Provided by: libsolv-doc_0.7.23-1_all bug

NAME

       libsolv-bindings - access libsolv from perl/python/ruby

DESCRIPTION

       Libsolv’s language bindings offer an abstract, object orientated interface to the library.
       The supported languages are currently perl, python, ruby and tcl. All example code (except
       in the specifics sections, of course) lists first the “C-ish” interface, then the syntax
       for perl, python, and ruby (in that order).

PERL SPECIFICS

       Libsolv’s perl bindings can be loaded with the following statement:

           use solv;

       Objects are either created by calling the new() method on a class or they are returned by
       calling methods on other objects.

           my $pool = solv::Pool->new();
           my $repo = $pool->add_repo("my_first_repo");

       Swig encapsulates all objects as tied hashes, thus the attributes can be accessed by
       treating the object as standard hash reference:

           $pool->{appdata} = 42;
           printf "appdata is %d\n", $pool->{appdata};

       A special exception to this are iterator objects, they are encapsulated as tied arrays so
       that it is possible to iterate with a for() statement:

           my $iter = $pool->solvables_iter();
           for my $solvable (@$iter) { ... };

       As a downside of this approach, iterator objects cannot have attributes.

       If an array needs to be passed to a method it is usually done by reference, if a method
       returns an array it returns it on the perl stack:

           my @problems = $solver->solve(\@jobs);

       Due to a bug in swig, stringification does not work for libsolv’s objects. Instead, you
       have to call the object’s str() method.

           print $dep->str() . "\n";

       Swig implements all constants as numeric variables (instead of the more natural constant
       subs), so don’t forget the leading “$” when accessing a constant. Also do not forget to
       prepend the namespace of the constant:

           $pool->set_flag($solv::Pool::POOL_FLAG_OBSOLETEUSESCOLORS, 1);

PYTHON SPECIFICS

       The python bindings can be loaded with:

           import solv

       Objects are either created by calling the constructor method for a class or they are
       returned by calling methods on other objects.

           pool = solv.Pool()
           repo = pool.add_repo("my_first_repo")

       Attributes can be accessed as usual:

           pool.appdata = 42
           print "appdata is %d" % (pool.appdata)

       Iterators also work as expected:

           for solvable in pool.solvables_iter():

       Arrays are passed and returned as list objects:

           jobs = []
           problems = solver.solve(jobs)

       The bindings define stringification for many classes, some also have a repr method to ease
       debugging.

           print dep
           print repr(repo)

       Constants are attributes of the corresponding classes:

           pool.set_flag(solv.Pool.POOL_FLAG_OBSOLETEUSESCOLORS, 1);

RUBY SPECIFICS

       The ruby bindings can be loaded with:

           require 'solv'

       Objects are either created by calling the new method on a class or they are returned by
       calling methods on other objects. Note that all classes start with an uppercase letter in
       ruby, so the class is called “Solv”.

           pool = Solv::Pool.new
           repo = pool.add_repo("my_first_repo")

       Attributes can be accessed as usual:

           pool.appdata = 42
           puts "appdata is #{pool.appdata}"

       Iterators also work as expected:

           for solvable in pool.solvables_iter() do ...

       Arrays are passed and returned as array objects:

           jobs = []
           problems = solver.solve(jobs)

       Most classes define a to_s method, so objects can be easily stringified. Many also define
       an inspect() method.

           puts dep
           puts repo.inspect

       Constants live in the namespace of the class they belong to:

           pool.set_flag(Solv::Pool::POOL_FLAG_OBSOLETEUSESCOLORS, 1);

       Note that boolean methods have an added trailing “?”, to be consistent with other ruby
       modules:

           puts "empty" if repo.isempty?

TCL SPECIFICS

       Libsolv’s tcl bindings can be loaded with the following statement:

           package require solv

       Objects are either created by calling class name prefixed with “new_”, or they are
       returned by calling methods on other objects.

           set pool [solv::new_Pool]
           set repo [$pool add_repo "my_first_repo"]

       Swig provides a “cget” method to read object attributes, and a “configure” method to write
       them:

           $pool configure -appdata 42
           puts "appdata is [$pool cget -appdata]"

       The tcl bindings provide a little helper to work with iterators in a foreach style:

           set iter [$pool solvables_iter]
           solv::iter s $iter { ... }

       libsolv’s arrays are mapped to tcl’s lists:

           set jobs [list $job1 $job2]
           set problems [$solver solve $jobs]
           puts "We have [llength $problems] problems..."

       Stringification is done by calling the object’s “str” method.

           puts [$dep str]

       There is one exception: you have to use “stringify” for Datamatch objects, as swig reports
       a clash with the “str” attribute. Some objects also support a “==” method for equality
       tests, and a “!=” method.

       Swig implements all constants as numeric variables, constants belonging to a libsolv class
       are prefixed with the class name:

           $pool set_flag $solv::Pool_POOL_FLAG_OBSOLETEUSESCOLORS 1
           puts [$solvable lookup_str $solv::SOLVABLE_SUMMARY]

THE SOLV CLASS

       This is the main namespace of the library, you cannot create objects of this type but it
       contains some useful constants.

   CONSTANTS
       Relational flag constants, the first three can be or-ed together

       REL_LT
           the “less than” bit

       REL_EQ
           the “equals to” bit

       REL_GT
           the “greater than” bit

       REL_ARCH
           used for relations that describe an extra architecture filter, the version part of the
           relation is interpreted as architecture.

       Special Solvable Ids

       SOLVID_META
           Access the meta section of a repository or repodata area. This is like an extra
           Solvable that has the Id SOLVID_META.

       SOLVID_POS
           Use the data position stored inside of the pool instead of accessing some solvable by
           Id. The bindings have the Datapos objects as an abstraction mechanism, so you most
           likely do not need this constant.

       Constant string Ids

       ID_NULL
           Always zero

       ID_EMPTY
           Always one, describes the empty string

       SOLVABLE_NAME
           The keyname Id of the name of the solvable.

       ...
           see the libsolv-constantids manpage for a list of fixed Ids.

THE POOL CLASS

       The pool is libsolv’s central resource manager. A pool consists of Solvables,
       Repositories, Dependencies, each indexed by Ids.

   CLASS METHODS
           Pool *Pool()
           my $pool = solv::Pool->new();
           pool = solv.Pool()
           pool = Solv::Pool.new()

       Create a new pool instance. In most cases you just need one pool. Note that the returned
       object "owns" the pool, i.e. if the object is freed, the pool is also freed. You can use
       the disown method to break this ownership relation.

   ATTRIBUTES
           void *appdata;                  /* read/write */
           $pool->{appdata}
           pool.appdata
           pool.appdata

       Application specific data that may be used in any way by the code using the pool.

           Solvable solvables[];           /* read only */
           my $solvable = $pool->{solvables}->[$solvid];
           solvable = pool.solvables[solvid]
           solvable = pool.solvables[solvid]

       Look up a Solvable by its id.

           Repo repos[];                   /* read only */
           my $repo = $pool->{repos}->[$repoid];
           repo = pool.repos[repoid]
           repo = pool.repos[repoid]

       Look up a Repository by its id.

           Repo *installed;                /* read/write */
           $pool->{installed} = $repo;
           pool.installed = repo
           pool.installed = repo

       Define which repository contains all the installed packages.

           const char *errstr;             /* read only */
           my $err = $pool->{errstr};
           err = pool.errstr
           err = pool.errstr

       Return the last error string that was stored in the pool.

   CONSTANTS
       POOL_FLAG_PROMOTEEPOCH
           Promote the epoch of the providing dependency to the requesting dependency if it does
           not contain an epoch. Used at some time in old rpm versions, modern systems should
           never need this.

       POOL_FLAG_FORBIDSELFCONFLICTS
           Disallow the installation of packages that conflict with themselves. Debian always
           allows self-conflicting packages, rpm used to forbid them but switched to also
           allowing them since rpm-4.9.0.

       POOL_FLAG_OBSOLETEUSESPROVIDES
           Make obsolete type dependency match against provides instead of just the name and
           version of packages. Very old versions of rpm used the name/version, then it got
           switched to provides and later switched back again to just name/version.

       POOL_FLAG_IMPLICITOBSOLETEUSESPROVIDES
           An implicit obsoletes is the internal mechanism to remove the old package on an
           update. The default is to remove all packages with the same name, rpm-5 switched to
           also removing packages providing the same name.

       POOL_FLAG_OBSOLETEUSESCOLORS
           Rpm’s multilib implementation distinguishes between 32bit and 64bit packages (the
           terminology is that they have a different color). If obsoleteusescolors is set,
           packages with different colors will not obsolete each other.

       POOL_FLAG_IMPLICITOBSOLETEUSESCOLORS
           Same as POOL_FLAG_OBSOLETEUSESCOLORS, but used to find out if packages of the same
           name can be installed in parallel. For current Fedora systems,
           POOL_FLAG_OBSOLETEUSESCOLORS should be false and POOL_FLAG_IMPLICITOBSOLETEUSESCOLORS
           should be true (this is the default if FEDORA is defined when libsolv is compiled).

       POOL_FLAG_NOINSTALLEDOBSOLETES
           Since version 4.9.0 rpm considers the obsoletes of installed packages when checking
           for dependency conflicts, thus you may not install a package that is obsoleted by some
           other installed package unless you also erase the other package.

       POOL_FLAG_HAVEDISTEPOCH
           Mandriva added a new field called distepoch that gets checked in version comparison if
           the epoch/version/release of two packages are the same.

       POOL_FLAG_NOOBSOLETESMULTIVERSION
           If a package is installed in multiversion mode, rpm used to ignore both the implicit
           obsoletes and the obsolete dependency of a package. This was changed to ignoring just
           the implicit obsoletes, thus you may install multiple versions of the same name, but
           obsoleted packages still get removed.

       POOL_FLAG_ADDFILEPROVIDESFILTERED
           Make the addfileprovides method only add files from the standard locations (i.e. the
           “bin” and “etc” directories). This is useful if you have only few packages that use
           non-standard file dependencies, but you still want the fast speed that
           addfileprovides() generates.

   METHODS
           void free()
           $pool->free();
           pool.free()
           pool.free()

       Force a free of the pool. After this call, you must not access any object that still
       references the pool.

           void disown()
           $pool->disown();
           pool.disown()
           pool.disown()

       Break the ownership relation between the binding object and the pool. After this call, the
       pool will not get freed even if the object goes out of scope. This also means that you
       must manually call the free method to free the pool data.

           void setdebuglevel(int level)
           $pool->setdebuglevel($level);
           pool.setdebuglevel(level)
           pool.setdebuglevel(level)

       Set the debug level. A value of zero means no debug output, the higher the value, the more
       output is generated.

           int set_flag(int flag, int value)
           my $oldvalue = $pool->set_flag($flag, $value);
           oldvalue = pool.set_flag(flag, value)
           oldvalue = pool.set_flag(flag, value)

           int get_flag(int flag)
           my $value = $pool->get_flag($flag);
           value = pool.get_flag(flag)
           value = pool.get_flag(flag)

       Set/get a pool specific flag. The flags define how the system works, e.g. how the package
       manager treats obsoletes. The default flags should be sane for most applications, but in
       some cases you may want to tweak a flag, for example if you want to solve package
       dependencies for some other system.

           void set_rootdir(const char *rootdir)
           $pool->set_rootdir(rootdir);
           pool.set_rootdir(rootdir)
           pool.set_rootdir(rootdir)

           const char *get_rootdir()
           my $rootdir = $pool->get_rootdir();
           rootdir = pool.get_rootdir()
           rootdir = pool.get_rootdir()

       Set/get the rootdir to use. This is useful if you want package management to work only in
       some directory, for example if you want to setup a chroot jail. Note that the rootdir will
       only be prepended to file paths if the REPO_USE_ROOTDIR flag is used.

           void setarch(const char *arch = 0)
           $pool->setarch();
           pool.setarch()
           pool.setarch()

       Set the architecture for your system. The architecture is used to determine which packages
       are installable. It defaults to the result of “uname -m”.

           Repo add_repo(const char *name)
           $repo = $pool->add_repo($name);
           repo = pool.add_repo(name)
           repo = pool.add_repo(name)

       Add a Repository with the specified name to the pool. The repository is empty on creation,
       use the repository methods to populate it with packages.

           Repoiterator repos_iter()
           for my $repo (@{$pool->repos_iter()})
           for repo in pool.repos_iter():
           for repo in pool.repos_iter()

       Iterate over the existing repositories.

           Solvableiterator solvables_iter()
           for my $solvable (@{$pool->solvables_iter()})
           for solvable in pool.solvables_iter():
           for solvable in pool.solvables_iter()

       Iterate over the existing solvables.

           Dep Dep(const char *str, bool create = 1)
           my $dep = $pool->Dep($string);
           dep = pool.Dep(string)
           dep = pool.Dep(string)

       Create an object describing a string or dependency. If the string is currently not in the
       pool and create is false, undef/None/nil is returned.

           void addfileprovides()
           $pool->addfileprovides();
           pool.addfileprovides()
           pool.addfileprovides()

           Id *addfileprovides_queue()
           my @ids = $pool->addfileprovides_queue();
           ids = pool.addfileprovides_queue()
           ids = pool.addfileprovides_queue()

       Some package managers like rpm allow dependencies on files contained in other packages. To
       allow libsolv to deal with those dependencies in an efficient way, you need to call the
       addfileprovides method after creating and reading all repositories. This method will scan
       all dependency for file names and then scan all packages for matching files. If a filename
       has been matched, it will be added to the provides list of the corresponding package. The
       addfileprovides_queue variant works the same way but returns an array containing all file
       dependencies. This information can be stored in the meta section of the repositories to
       speed up the next time the repository is loaded and addfileprovides is called.

           void createwhatprovides()
           $pool->createwhatprovides();
           pool.createwhatprovides()
           pool.createwhatprovides()

       Create the internal “whatprovides” hash over all of the provides of all installable
       packages. This method must be called before doing any lookups on provides. It’s encouraged
       to do it right after all repos are set up, usually right after the call to
       addfileprovides().

           Solvable *whatprovides(DepId dep)
           my @solvables = $pool->whatprovides($dep);
           solvables = pool.whatprovides(dep)
           solvables = pool.whatprovides(dep)

       Return all solvables that provide the specified dependency. You can use either a Dep
       object or a simple Id as argument.

           Solvable *best_solvables(Solvable *solvables, int flags = 0)
           my @solvables = $pool->best_solvables($solvables);
           solvables = pool.best_solvables(solvables)
           solvables = pool.best_solvables(solvables)

       Filter list of solvables by repo priority, architecture and version.

           Solvable *whatcontainsdep(Id keyname, DepId dep, Id marker = -1)
           my @solvables = $pool->whatcontainsdep($keyname, $dep);
           solvables = pool.whatcontainsdep(keyname, dep)
           solvables = pool.whatcontainsdep(keyname, dep)

       Return all solvables for which keyname contains the dependency.

           Solvable *whatmatchesdep(Id keyname, DepId dep, Id marker = -1)
           my @solvables = $pool->whatmatchesdep($keyname, $sdep);
           solvables = pool.whatmatchesdep(keyname, dep)
           solvables = pool.whatmatchesdep(keyname, dep)

       Return all solvables that have dependencies in keyname that match the dependency.

           Solvable *whatmatchessolvable(Id keyname, Solvable solvable, Id marker = -1)
           my @solvables = $pool->whatmatchessolvable($keyname, $solvable);
           solvables = pool.whatmatchessolvable(keyname, solvable)
           solvables = pool.whatmatchessolvable(keyname, solvable)

       Return all solvables that match package dependencies against solvable’s provides.

           Id *matchprovidingids(const char *match, int flags)
           my @ids = $pool->matchprovidingids($match, $flags);
           ids = pool.matchprovidingids(match, flags)
           ids = pool.matchprovidingids(match, flags)

       Search the names of all provides and return the ones matching the specified string. See
       the Dataiterator class for the allowed flags.

           Id towhatprovides(Id *ids)
           my $offset = $pool->towhatprovides(\@ids);
           offset = pool.towhatprovides(ids)
           offset = pool.towhatprovides(ids)

       “Internalize” an array containing Ids. The returned value can be used to create solver
       jobs working on a specific set of packages. See the Solver class for more information.

           void set_namespaceproviders(DepId ns, DepId evr, bool value = 1)
           $pool->set_namespaceproviders($ns, $evr, 1);
           pool.set_namespaceproviders(ns, evr, True)
           pool.set_namespaceproviders(ns, evr, true)

       Manually set a namespace provides entry in the whatprovides index.

           void flush_namespaceproviders(DepId ns, DepId evr)
           $pool->flush_namespaceproviders($ns, $evr);
           $pool.flush_namespaceproviders(ns, evr)
           $pool.flush_namespaceproviders(ns, evr)

       Flush the cache of all namespaceprovides matching the specified namespace dependency. You
       can use zero as a wildcard argument.

           bool isknownarch(DepId id)
           my $bool = $pool->isknownarch($id);
           bool = pool.isknownarch(id)
           bool = pool.isknownarch?(id)

       Return true if the specified Id describes a known architecture.

           Solver Solver()
           my $solver = $pool->Solver();
           solver = pool.Solver()
           solver = pool.Solver()

       Create a new solver object.

           Job Job(int how, Id what)
           my $job = $pool->Job($how, $what);
           job = pool.Job(how, what)
           job = pool.Job(how, what)

       Create a new Job object. Kind of low level, in most cases you would instead use a
       Selection or Dep job constructor.

           Selection Selection()
           my $sel = $pool->Selection();
           sel = pool.Selection()
           sel = pool.Selection()

       Create an empty selection. Useful as a starting point for merging other selections.

           Selection Selection_all()
           my $sel = $pool->Selection_all();
           sel = pool.Selection_all()
           sel = pool.Selection_all()

       Create a selection containing all packages. Useful as starting point for intersecting
       other selections or for update/distupgrade jobs.

           Selection select(const char *name, int flags)
           my $sel = $pool->select($name, $flags);
           sel = pool.select(name, flags)
           sel = pool.select(name, flags)

       Create a selection by matching packages against the specified string. See the Selection
       class for a list of flags and how to create solver jobs from a selection.

           Selection matchdeps(const char *name, int flags, Id keyname, Id marker = -1)
           my $sel = $pool->matchdeps($name, $flags, $keyname);
           sel = pool.matchdeps(name, flags, keyname)
           sel = pool.matchdeps(name, flags, keyname)

       Create a selection by matching package dependencies against the specified string. This can
       be used if you want to match other dependency types than “provides”.

           Selection matchdepid(DepId dep, int flags, Id keyname, Id marker = -1)
           my $sel = $pool->matchdepid($dep, $flags, $keyname);
           sel = pool.matchdepid(dep, flags, keyname)
           sel = pool.matchdepid(dep, flags, keyname)

       Create a selection by matching package dependencies against the specified dependency. This
       may be faster than matchdeps and also works with complex dependencies. The downside is
       that you cannot use globs or case insensitive matching.

           Selection matchsolvable(Solvable solvable, int flags, Id keyname, Id marker = -1)
           my $sel = $pool->matchsolvable($solvable, $flags, $keyname);
           sel = pool.matchsolvable(solvable, flags, keyname)
           sel = pool.matchsolvable(solvable, flags, keyname)

       Create a selection by matching package dependencies against the specified solvable’s
       provides.

           void setpooljobs(Jobs *jobs)
           $pool->setpooljobs(\@jobs);
           pool.setpooljobs(jobs)
           pool.setpooljobs(jobs)

           Job *getpooljobs()
           @jobs = $pool->getpooljobs();
           jobs = pool.getpooljobs()
           jobs = pool.getpooljobs()

       Get/Set fixed jobs stored in the pool. Those jobs are automatically appended to all solver
       jobs, they are meant for fixed configurations like which packages can be multiversion
       installed, which packages were userinstalled, or which packages must not be erased.

           void set_loadcallback(Callable *callback)
           $pool->setloadcallback(\&callbackfunction);
           pool.setloadcallback(callbackfunction)
           pool.setloadcallback { |repodata| ... }

       Set the callback function called when repository metadata needs to be loaded on demand. To
       make use of this feature, you need to create repodata stubs that tell the library which
       data is available but not loaded. If later on the data needs to be accessed, the callback
       function is called with a repodata argument. You can then load the data (maybe fetching it
       first from a remote server). The callback should return true if the data has been made
       available.

           /* bindings only */
           $pool->appdata_disown()
           pool.appdata_disown()
           pool.appdata_disown()

       Decrement the reference count of the appdata object. This can be used to break circular
       references (e.g. if the pool’s appdata value points to some meta data structure that
       contains a pool handle). If used incorrectly, this method can lead to application crashes,
       so beware. (This method is a no-op for ruby and tcl.)

           Id *get_considered_list()
           my @ids = $pool->get_considered_list();
           ids = pool.get_considered_list()
           ids = pool.get_considered_list()

           void set_considered_list(Id *ids)
           $pool->set_considered_list(\@ids);
           pool.set_considered_list(ids)
           pool.set_considered_list(ids)

       Get/set the list of solvables that are eligible for installation. Note that you need to
       recreate the whatprovides hash after changing the list.

           Id *get_disabled_list()
           my @ids = $pool->get_disabled_list();
           ids = pool.get_disabled_list()
           ids = pool.get_disabled_list()

           void set_disabled_list(Id *ids)
           $pool->set_disabled_list(\@ids);
           pool.set_disabled_list(ids)
           pool.set_disabled_list(ids)

       Get/set the list of solvables that are not eligible for installation. This is basically
       the inverse of the “considered” methods above, i.e. calling “set_disabled_list()” with an
       empty list will make all solvables eligible for installation. Note you need to recreate
       the whatprovides hash after changing the list.

           const char *solvableset2str(Solvable *solvables)
           my $str = $pool->solvableset2str($solvables);
           str = pool.solvableset2str(solvables)
           str = pool.solvableset2str(solvables)

       Return a string describing a list of solvables. The method tries to reduce the output by
       using version ranges if possible.

   DATA RETRIEVAL METHODS
       In the following functions, the keyname argument describes what to retrieve. For the
       standard cases you can use the available Id constants. For example,

           $solv::SOLVABLE_SUMMARY
           solv.SOLVABLE_SUMMARY
           Solv::SOLVABLE_SUMMARY

       selects the “Summary” entry of a solvable. The solvid argument selects the desired
       solvable by Id.

           const char *lookup_str(Id solvid, Id keyname)
           my $string = $pool->lookup_str($solvid, $keyname);
           string = pool.lookup_str(solvid, keyname)
           string = pool.lookup_str(solvid, keyname)

           Id lookup_id(Id solvid, Id keyname)
           my $id = $pool->lookup_id($solvid, $keyname);
           id = pool.lookup_id(solvid, keyname)
           id = pool.lookup_id(solvid, keyname)

           unsigned long long lookup_num(Id solvid, Id keyname, unsigned long long notfound = 0)
           my $num = $pool->lookup_num($solvid, $keyname);
           num = pool.lookup_num(solvid, keyname)
           num = pool.lookup_num(solvid, keyname)

           bool lookup_void(Id solvid, Id keyname)
           my $bool = $pool->lookup_void($solvid, $keyname);
           bool = pool.lookup_void(solvid, keyname)
           bool = pool.lookup_void(solvid, keyname)

           Id *lookup_idarray(Id solvid, Id keyname)
           my @ids = $pool->lookup_idarray($solvid, $keyname);
           ids = pool.lookup_idarray(solvid, keyname)
           ids = pool.lookup_idarray(solvid, keyname)

           Chksum lookup_checksum(Id solvid, Id keyname)
           my $chksum = $pool->lookup_checksum($solvid, $keyname);
           chksum = pool.lookup_checksum(solvid, keyname)
           chksum = pool.lookup_checksum(solvid, keyname)

       Lookup functions. Return the data element stored in the specified solvable. You should
       probably use the methods of the Solvable class instead.

           Dataiterator Dataiterator(Id keyname, const char *match = 0, int flags = 0)
           my $di = $pool->Dataiterator($keyname, $match, $flags);
           di = pool.Dataiterator(keyname, match, flags)
           di = pool.Dataiterator(keyname, match, flags)

           Dataiterator Dataiterator_solvid(Id solvid, Id keyname, const char *match = 0, int flags = 0)
           my $di = $pool->Dataiterator($solvid, $keyname, $match, $flags);
           di = pool.Dataiterator(solvid, keyname, match, flags)
           di = pool.Dataiterator(solvid, keyname, match, flags)

           for my $d (@$di)
           for d in di:
           for d in di

       Iterate over the matching data elements. See the Dataiterator class for more information.
       The Dataiterator method iterates over all solvables in the pool, whereas the
       Dataiterator_solvid only iterates over the specified solvable.

   ID METHODS
       The following methods deal with Ids, i.e. integers representing objects in the pool. They
       are considered “low level”, in most cases you would not use them but instead the object
       orientated methods.

           Repo id2repo(Id id)
           $repo = $pool->id2repo($id);
           repo = pool.id2repo(id)
           repo = pool.id2repo(id)

       Lookup an existing Repository by id. You can also do this by using the repos attribute.

           Solvable id2solvable(Id id)
           $solvable = $pool->id2solvable($id);
           solvable = pool.id2solvable(id)
           solvable = pool.id2solvable(id)

       Lookup an existing Repository by id. You can also do this by using the solvables
       attribute.

           const char *solvid2str(Id id)
           my $str = $pool->solvid2str($id);
           str = pool.solvid2str(id)
           str = pool.solvid2str(id)

       Return a string describing the Solvable with the specified id. The string consists of the
       name, version, and architecture of the Solvable.

           const char *solvidset2str(Id *solvids)
           my $str = $pool->solvidset2str(\@solvids);
           str = pool.solvidset2str(solvids)
           str = pool.solvidset2str(solvids)

       Return a string describing a list of solvables. The method tries to reduce the output by
       using version ranges if possible.

           Id str2id(const char *str, bool create = 1)
           my $id = pool->str2id($string);
           id = pool.str2id(string)
           id = pool.str2id(string)

           const char *id2str(Id id)
           $string = pool->id2str($id);
           string = pool.id2str(id)
           string = pool.id2str(id)

       Convert a string into an Id and back. If the string is currently not in the pool and
       create is false, zero is returned.

           Id rel2id(Id name, Id evr, int flags, bool create = 1)
           my $id = pool->rel2id($nameid, $evrid, $flags);
           id = pool.rel2id(nameid, evrid, flags)
           id = pool.rel2id(nameid, evrid, flags)

       Create a “relational” dependency. Such dependencies consist of a name part, flags
       describing the relation, and a version part. The flags are:

           $solv::REL_EQ | $solv::REL_GT | $solv::REL_LT
           solv.REL_EQ | solv.REL_GT | solv.REL_LT
           Solv::REL_EQ | Solv::REL_GT | Solv::REL_LT

       Thus, if you want a “<=” relation, you would use REL_LT | REL_EQ.

           Id id2langid(Id id, const char *lang, bool create = 1)
           my $id = $pool->id2langid($id, $language);
           id = pool.id2langid(id, language)
           id = pool.id2langid(id, language)

       Create a language specific Id from some other id. This function simply converts the id
       into a string, appends a dot and the specified language to the string and converts the
       result back into an Id.

           const char *dep2str(Id id)
           $string = pool->dep2str($id);
           string = pool.dep2str(id)
           string = pool.dep2str(id)

       Convert a dependency id into a string. If the id is just a string, this function has the
       same effect as id2str(). For relational dependencies, the result is the correct “name
       relation evr” string.

THE DEPENDENCY CLASS

       The dependency class is an object orientated way to work with strings and dependencies.
       Internally, dependencies are represented as Ids, i.e. simple numbers. Dependency objects
       can be constructed by using the Pool’s Dep() method.

   ATTRIBUTES
           Pool *pool;             /* read only */
           $dep->{pool}
           dep.pool
           dep.pool

       Back reference to the pool this dependency belongs to.

           Id id;          /* read only */
           $dep->{id}
           dep.id
           dep.id

       The id of this dependency.

   METHODS
           Dep Rel(int flags, DepId evrid, bool create = 1)
           my $reldep = $dep->Rel($flags, $evrdep);
           reldep = dep.Rel(flags, evrdep)
           reldep = dep.Rel(flags, evrdep)

       Create a relational dependency from the caller dependency, the flags, and a dependency
       describing the “version” part. See the pool’s rel2id method for a description of the
       flags.

           Selection Selection_name(int setflags = 0)
           my $sel = $dep->Selection_name();
           sel = dep.Selection_name()
           sel = dep.Selection_name()

       Create a Selection from a dependency. The selection consists of all packages that have a
       name equal to the dependency. If the dependency is of a relational type, the packages
       version must also fulfill the dependency.

           Selection Selection_provides(int setflags = 0)
           my $sel = $dep->Selection_provides();
           sel = dep.Selection_provides()
           sel = dep.Selection_provides()

       Create a Selection from a dependency. The selection consists of all packages that have at
       least one provides matching the dependency.

           const char *str()
           my $str = $dep->str();
           str = $dep.str()
           str = $dep.str()

       Return a string describing the dependency.

           <stringification>
           my $str = $dep->str;
           str = str(dep)
           str = dep.to_s

       Same as calling the str() method.

           <equality>
           if ($dep1 == $dep2)
           if dep1 == dep2:
           if dep1 == dep2

       Two dependencies are equal if they are part of the same pool and have the same ids.

THE REPOSITORY CLASS

       A Repository describes a group of packages, normally coming from the same source.
       Repositories are created by the Pool’s add_repo() method.

   ATTRIBUTES
           Pool *pool;                     /* read only */
           $repo->{pool}
           repo.pool
           repo.pool

       Back reference to the pool this dependency belongs to.

           Id id;                          /* read only */
           $repo->{id}
           repo.id
           repo.id

       The id of the repository.

           const char *name;               /* read/write */
           $repo->{name}
           repo.name
           repo.name

       The repositories name. To libsolv, the name is just a string with no specific meaning.

           int priority;                   /* read/write */
           $repo->{priority}
           repo.priority
           repo.priority

       The priority of the repository. A higher number means that packages of this repository
       will be chosen over other repositories, even if they have a greater package version.

           int subpriority;                /* read/write */
           $repo->{subpriority}
           repo.subpriority
           repo.subpriority

       The sub-priority of the repository. This value is compared when the priorities of two
       repositories are the same. It is useful to make the library prefer on-disk repositories to
       remote ones.

           int nsolvables;                 /* read only */
           $repo->{nsolvables}
           repo.nsolvables
           repo.nsolvables

       The number of solvables in this repository.

           void *appdata;                  /* read/write */
           $repo->{appdata}
           repo.appdata
           repo.appdata

       Application specific data that may be used in any way by the code using the repository.

           Datapos *meta;                  /* read only */
           $repo->{meta}
           repo.meta
           repo.meta

       Return a Datapos object of the repodata’s metadata. You can use the lookup methods of the
       Datapos class to lookup metadata attributes, like the repository timestamp.

   CONSTANTS
       REPO_REUSE_REPODATA
           Reuse the last repository data area (“repodata”) instead of creating a new area.

       REPO_NO_INTERNALIZE
           Do not internalize the added repository data. This is useful if you plan to add more
           data because internalization is a costly operation.

       REPO_LOCALPOOL
           Use the repodata’s pool for Id storage instead of the global pool. Useful if you don’t
           want to pollute the global pool with many unneeded ids, like when storing the
           filelist.

       REPO_USE_LOADING
           Use the repodata that is currently being loaded instead of creating a new one. This
           only makes sense if used in a load callback.

       REPO_EXTEND_SOLVABLES
           Do not create new solvables for the new data, but match existing solvables and add the
           data to them. Repository metadata is often split into multiple parts, with one primary
           file describing all packages and other parts holding information that is normally not
           needed, like the changelog.

       REPO_USE_ROOTDIR
           Prepend the pool’s rootdir to the path when doing file operations.

       REPO_NO_LOCATION
           Do not add a location element to the solvables. Useful if the solvables are not in the
           final position, so you can add the correct location later in your code.

       SOLV_ADD_NO_STUBS
           Do not create stubs for repository parts that can be downloaded on demand.

       SUSETAGS_RECORD_SHARES
           This is specific to the add_susetags() method. Susetags allows one to refer to already
           read packages to save disk space. If this data sharing needs to work over multiple
           calls to add_susetags, you need to specify this flag so that the share information is
           made available to subsequent calls.

   METHODS
           void free(bool reuseids = 0)
           $repo->free();
           repo.free()
           repo.free()

       Free the repository and all solvables it contains. If reuseids is set to true, the
       solvable ids and the repository id may be reused by the library when added new solvables.
       Thus you should leave it false if you are not sure that somebody holds a reference.

           void empty(bool reuseids = 0)
           $repo->empty();
           repo.empty()
           repo.empty()

       Free all the solvables in a repository. The repository will be empty after this call. See
       the free() method for the meaning of reuseids.

           bool isempty()
           $repo->isempty()
           repo.empty()
           repo.empty?

       Return true if there are no solvables in this repository.

           void internalize()
           $repo->internalize();
           repo.internalize()
           repo.internalize()

       Internalize added data. Data must be internalized before it is available to the lookup and
       data iterator functions.

           bool write(FILE *fp)
           $repo->write($fp)
           repo.write(fp)
           repo.write(fp)

       Write a repo as a “solv” file. These files can be read very fast and thus are a good way
       to cache repository data. Returns false if there was some error writing the file.

           Solvableiterator solvables_iter()
           for my $solvable (@{$repo->solvables_iter()})
           for solvable in repo.solvables_iter():
           for solvable in repo.solvables_iter()

       Iterate over all solvables in a repository.

           Repodata add_repodata(int flags = 0)
           my $repodata = $repo->add_repodata();
           repodata = repo.add_repodata()
           repodata = repo.add_repodata()

       Add a new repodata area to the repository. This is normally automatically done by the
       repo_add methods, so you need this method only in very rare circumstances.

           void create_stubs()
           $repo->create_stubs();
           repo.create_stubs()
           repo.create_stubs()

       Calls the create_stubs() repodata method for the last repodata of the repository.

           bool iscontiguous()
           $repo->iscontiguous()
           repo.iscontiguous()
           repo.iscontiguous?

       Return true if the solvables of this repository are all in a single block with no holes,
       i.e. they have consecutive ids.

           Repodata first_repodata()
           my $repodata = $repo->first_repodata();
           repodata = repo.first_repodata()
           repodata = repo.first_repodata()

       Checks if all repodatas but the first repodata are extensions, and return the first
       repodata if this is the case. Useful if you want to do a store/retrieve sequence on the
       repository to reduce the memory using and enable paging, as this does not work if the
       repository contains multiple non-extension repodata areas.

           Selection Selection(int setflags = 0)
           my $sel = $repo->Selection();
           sel = repo.Selection()
           sel = repo.Selection()

       Create a Selection consisting of all packages in the repository.

           Dataiterator Dataiterator(Id key, const char *match = 0, int flags = 0)
           my $di = $repo->Dataiterator($keyname, $match, $flags);
           di = repo.Dataiterator(keyname, match, flags)
           di = repo.Dataiterator(keyname, match, flags)

           Dataiterator Dataiterator_meta(Id key, const char *match = 0, int flags = 0)
           my $di = $repo->Dataiterator_meta($keyname, $match, $flags);
           di = repo.Dataiterator_meta(keyname, match, flags)
           di = repo.Dataiterator_meta(keyname, match, flags)

           for my $d (@$di)
           for d in di:
           for d in di

       Iterate over the matching data elements in this repository. See the Dataiterator class for
       more information. The Dataiterator() method iterates over all solvables in a repository,
       whereas the Dataiterator_meta method only iterates over the repository’s meta data.

           <stringification>
           my $str = $repo->str;
           str = str(repo)
           str = repo.to_s

       Return the name of the repository, or "Repo#<id>" if no name is set.

           <equality>
           if ($repo1 == $repo2)
           if repo1 == repo2:
           if repo1 == repo2

       Two repositories are equal if they belong to the same pool and have the same id.

   DATA ADD METHODS
           Solvable add_solvable()
           $repo->add_solvable();
           repo.add_solvable()
           repo.add_solvable()

       Add a single empty solvable to the repository. Returns a Solvable object, see the Solvable
       class for more information.

           bool add_solv(const char *name, int flags = 0)
           $repo->add_solv($name);
           repo.add_solv(name)
           repo.add_solv(name)

           bool add_solv(FILE *fp, int flags = 0)
           $repo->add_solv($fp);
           repo.add_solv(fp)
           repo.add_solv(fp)

       Read a “solv” file and add its contents to the repository. These files can be written with
       the write() method and are normally used as fast cache for repository metadata.

           bool add_rpmdb(int flags = 0)
           $repo->add_rpmdb();
           repo.add_rpmdb()
           repo.add_rpmdb()

           bool add_rpmdb_reffp(FILE *reffp, int flags = 0)
           $repo->add_rpmdb_reffp($reffp);
           repo.add_rpmdb_reffp(reffp)
           repo.add_rpmdb_reffp(reffp)

       Add the contents of the rpm database to the repository. If a solv file containing an old
       version of the database is available, it can be passed as reffp to speed up reading.

           Solvable add_rpm(const char *filename, int flags = 0)
           my $solvable = $repo->add_rpm($filename);
           solvable = repo.add_rpm(filename)
           solvable = repo.add_rpm(filename)

       Add the metadata of a single rpm package to the repository.

           bool add_rpmdb_pubkeys(int flags = 0)
           $repo->add_rpmdb_pubkeys();
           repo.add_rpmdb_pubkeys()
           repo.add_rpmdb_pubkeys()

       Add all pubkeys contained in the rpm database to the repository. Note that newer rpm
       versions also allow one to store the pubkeys in some directory instead of the rpm
       database.

           Solvable add_pubkey(const char *keyfile, int flags = 0)
           my $solvable = $repo->add_pubkey($keyfile);
           solvable = repo.add_pubkey(keyfile)
           solvable = repo.add_pubkey(keyfile)

       Add a pubkey from a file to the repository.

           bool add_rpmmd(FILE *fp, const char *language, int flags = 0)
           $repo->add_rpmmd($fp, undef);
           repo.add_rpmmd(fp, None)
           repo.add_rpmmd(fp, nil)

       Add metadata stored in the "rpm-md" format (i.e. from files in the “repodata” directory)
       to a repository. Supported files are "primary", "filelists", "other", "suseinfo". Do not
       forget to specify the REPO_EXTEND_SOLVABLES for extension files like "filelists" and
       "other". Use the language parameter if you have language extension files, otherwise simply
       use a undef/None/nil parameter.

           bool add_repomdxml(FILE *fp, int flags = 0)
           $repo->add_repomdxml($fp);
           repo.add_repomdxml(fp)
           repo.add_repomdxml(fp)

       Add the repomd.xml meta description from the "rpm-md" format to the repository. This file
       contains information about the repository like keywords, and also a list of all database
       files with checksums. The data is added to the "meta" section of the repository, i.e. no
       package gets created.

           bool add_updateinfoxml(FILE *fp, int flags = 0)
           $repo->add_updateinfoxml($fp);
           repo.add_updateinfoxml(fp)
           repo.add_updateinfoxml(fp)

       Add the updateinfo.xml file containing available maintenance updates to the repository.
       All updates are created as special packages that have a "patch:" prefix in their name.

           bool add_deltainfoxml(FILE *fp, int flags = 0)
           $repo->add_deltainfoxml($fp);
           repo.add_deltainfoxml(fp)
           repo.add_deltainfoxml(fp)

       Add the deltainfo.xml file (also called prestodelta.xml) containing available delta-rpms
       to the repository. The data is added to the "meta" section, i.e. no package gets created.

           bool add_debdb(int flags = 0)
           $repo->add_debdb();
           repo.add_debdb()
           repo.add_debdb()

       Add the contents of the debian installed package database to the repository.

           bool add_debpackages(FILE *fp, int flags = 0)
           $repo->add_debpackages($fp);
           repo.add_debpackages($fp)
           repo.add_debpackages($fp)

       Add the contents of the debian repository metadata (the "packages" file) to the
       repository.

           Solvable add_deb(const char *filename, int flags = 0)
           my $solvable = $repo->add_deb($filename);
           solvable = repo.add_deb(filename)
           solvable = repo.add_deb(filename)

       Add the metadata of a single deb package to the repository.

           bool add_mdk(FILE *fp, int flags = 0)
           $repo->add_mdk($fp);
           repo.add_mdk(fp)
           repo.add_mdk(fp)

       Add the contents of the mageia/mandriva repository metadata (the "synthesis.hdlist" file)
       to the repository.

           bool add_mdk_info(FILE *fp, int flags = 0)
           $repo->add_mdk_info($fp);
           repo.add_mdk_info(fp)
           repo.add_mdk_info(fp)

       Extend the packages from the synthesis file with the info.xml and files.xml data. Do not
       forget to specify REPO_EXTEND_SOLVABLES.

           bool add_arch_repo(FILE *fp, int flags = 0)
           $repo->add_arch_repo($fp);
           repo.add_arch_repo(fp)
           repo.add_arch_repo(fp)

       Add the contents of the archlinux repository metadata (the ".db.tar" file) to the
       repository.

           bool add_arch_local(const char *dir, int flags = 0)
           $repo->add_arch_local($dir);
           repo.add_arch_local(dir)
           repo.add_arch_local(dir)

       Add the contents of the archlinux installed package database to the repository. The dir
       parameter is usually set to "/var/lib/pacman/local".

           bool add_content(FILE *fp, int flags = 0)
           $repo->add_content($fp);
           repo.add_content(fp)
           repo.add_content(fp)

       Add the “content” meta description from the susetags format to the repository. This file
       contains information about the repository like keywords, and also a list of all database
       files with checksums. The data is added to the "meta" section of the repository, i.e. no
       package gets created.

           bool add_susetags(FILE *fp, Id defvendor, const char *language, int flags = 0)
           $repo->add_susetags($fp, $defvendor, $language);
           repo.add_susetags(fp, defvendor, language)
           repo.add_susetags(fp, defvendor, language)

       Add repository metadata in the susetags format to the repository. Like with add_rpmmd, you
       can specify a language if you have language extension files. The defvendor parameter
       provides a default vendor for packages with missing vendors, it is usually provided in the
       content file.

           bool add_products(const char *dir, int flags = 0)
           $repo->add_products($dir);
           repo.add_products(dir)
           repo.add_products(dir)

       Add the installed SUSE products database to the repository. The dir parameter is usually
       "/etc/products.d".

THE SOLVABLE CLASS

       A solvable describes all the information of one package. Each solvable belongs to one
       repository, it can be added and filled manually but in most cases solvables will get
       created by the repo_add methods.

   ATTRIBUTES
           Repo *repo;                     /* read only */
           $solvable->{repo}
           solvable.repo
           solvable.repo

       The repository this solvable belongs to.

           Pool *pool;                     /* read only */
           $solvable->{pool}
           solvable.pool
           solvable.pool

       The pool this solvable belongs to, same as the pool of the repo.

           Id id;                          /* read only */
           $solvable->{id}
           solvable.id
           solvable.id

       The specific id of the solvable.

           char *name;                     /* read/write */
           $solvable->{name}
           solvable.name
           solvable.name

           char *evr;                      /* read/write */
           $solvable->{evr}
           solvable.evr
           solvable.evr

           char *arch;                     /* read/write */
           $solvable->{arch}
           solvable.arch
           solvable.arch

           char *vendor;                   /* read/write */
           $solvable->{vendor}
           solvable.vendor
           solvable.vendor

       Easy access to often used attributes of solvables. They are internally stored as Ids.

           Id nameid;                      /* read/write */
           $solvable->{nameid}
           solvable.nameid
           solvable.nameid

           Id evrid;                       /* read/write */
           $solvable->{evrid}
           solvable.evrid
           solvable.evrid

           Id archid;                      /* read/write */
           $solvable->{archid}
           solvable.archid
           solvable.archid

           Id vendorid;                    /* read/write */
           $solvable->{vendorid}
           solvable.vendorid
           solvable.vendorid

       Raw interface to the ids. Useful if you want to search for a specific id and want to avoid
       the string compare overhead.

   METHODS
           const char *lookup_str(Id keyname)
           my $string = $solvable->lookup_str($keyname);
           string = solvable.lookup_str(keyname)
           string = solvable.lookup_str(keyname)

           Id lookup_id(Id keyname)
           my $id = $solvable->lookup_id($keyname);
           id = solvable.lookup_id(keyname)
           id = solvable.lookup_id(keyname)

           unsigned long long lookup_num(Id keyname, unsigned long long notfound = 0)
           my $num = $solvable->lookup_num($keyname);
           num = solvable.lookup_num(keyname)
           num = solvable.lookup_num(keyname)

           bool lookup_void(Id keyname)
           my $bool = $solvable->lookup_void($keyname);
           bool = solvable.lookup_void(keyname)
           bool = solvable.lookup_void(keyname)

           Chksum lookup_checksum(Id keyname)
           my $chksum = $solvable->lookup_checksum($keyname);
           chksum = solvable.lookup_checksum(keyname)
           chksum = solvable.lookup_checksum(keyname)

           Id *lookup_idarray(Id keyname, Id marker = -1)
           my @ids = $solvable->lookup_idarray($keyname);
           ids = solvable.lookup_idarray(keyname)
           ids = solvable.lookup_idarray(keyname)

           Dep *lookup_deparray(Id keyname, Id marker = -1)
           my @deps = $solvable->lookup_deparray($keyname);
           deps = solvable.lookup_deparray(keyname)
           deps = solvable.lookup_deparray(keyname)

       Generic lookup methods. Retrieve data stored for the specific keyname. The
       lookup_idarray() method will return an array of Ids, use lookup_deparray if you want an
       array of Dependency objects instead. Some Id arrays contain two parts of data divided by a
       specific marker, for example the provides array uses the SOLVABLE_FILEMARKER id to store
       both the ids provided by the package and the ids added by the addfileprovides method. The
       default, -1, translates to the correct marker for the keyname and returns the first part
       of the array, use 1 to select the second part or 0 to retrieve all ids including the
       marker.

           const char *lookup_location(unsigned int *OUTPUT)
           my ($location, $mediano) = $solvable->lookup_location();
           location, mediano = solvable.lookup_location()
           location, mediano = solvable.lookup_location()

       Return a tuple containing the on-media location and an optional media number for
       multi-part repositories (e.g. repositories spawning multiple DVDs).

           const char *lookup_sourcepkg()
           my $sourcepkg = $solvable->lookup_sourcepkg();
           sourcepkg = solvable.lookup_sourcepkg()
           sourcepkg = solvable.lookup_sourcepkg()

       Return a sourcepkg name associated with solvable.

           Dataiterator Dataiterator(Id keyname, const char *match = 0, int flags = 0)
           my $di = $solvable->Dataiterator($keyname, $match, $flags);
           di = solvable.Dataiterator(keyname, match, flags)
           di = solvable.Dataiterator(keyname, match, flags)

           for my $d (@$di)
           for d in di:
           for d in di

       Iterate over the matching data elements. See the Dataiterator class for more information.

           void add_deparray(Id keyname, DepId dep, Id marker = -1)
           $solvable->add_deparray($keyname, $dep);
           solvable.add_deparray(keyname, dep)
           solvable.add_deparray(keyname, dep)

       Add a new dependency to the attributes stored in keyname.

           void unset(Id keyname)
           $solvable->unset($keyname);
           solvable.unset(keyname)
           solvable.unset(keyname)

       Delete data stored for the specific keyname.

           bool installable()
           $solvable->installable()
           solvable.installable()
           solvable.installable?

       Return true if the solvable is installable on the system. Solvables are not installable if
       the system does not support their architecture.

           bool isinstalled()
           $solvable->isinstalled()
           solvable.isinstalled()
           solvable.isinstalled?

       Return true if the solvable is installed on the system.

           bool identical(Solvable *other)
           $solvable->identical($other)
           solvable.identical(other)
           solvable.identical?(other)

       Return true if the two solvables are identical.

           int evrcmp(Solvable *other)
           $solvable->evrcmp($other)
           solvable.evrcmp(other)
           solvable.evrcmp(other)

       Returns -1 if the epoch/version/release of the solvable is less than the one from the
       other solvable, 1 if it is greater, and 0 if they are equal. Note that "equal" does not
       mean that the evr is identical.

           int matchesdep(Id keyname, DepId id, Id marker = -1)
           $solvable->matchesdep($keyname, $dep)
           solvable.matchesdep(keyname, dep)
           solvable.matchesdep?(keyname, dep)

       Return true if the dependencies stored in keyname match the specified dependency.

           Selection Selection(int setflags = 0)
           my $sel = $solvable->Selection();
           sel = solvable.Selection()
           sel = solvable.Selection()

       Create a Selection containing just the single solvable.

           const char *str()
           my $str = $solvable->str();
           str = $solvable.str()
           str = $solvable.str()

       Return a string describing the solvable. The string consists of the name, version, and
       architecture of the Solvable.

           <stringification>
           my $str = $solvable->str;
           str = str(solvable)
           str = solvable.to_s

       Same as calling the str() method.

           <equality>
           if ($solvable1 == $solvable2)
           if solvable1 == solvable2:
           if solvable1 == solvable2

       Two solvables are equal if they are part of the same pool and have the same ids.

THE DATAITERATOR CLASS

       Dataiterators can be used to do complex string searches or to iterate over arrays. They
       can be created via the constructors in the Pool, Repo, and Solvable classes. The Repo and
       Solvable constructors will limit the search to the repository or the specific package.

   CONSTANTS
       SEARCH_STRING
           Return a match if the search string matches the value.

       SEARCH_STRINGSTART
           Return a match if the value starts with the search string.

       SEARCH_STRINGEND
           Return a match if the value ends with the search string.

       SEARCH_SUBSTRING
           Return a match if the search string can be matched somewhere in the value.

       SEARCH_GLOB
           Do a glob match of the search string against the value.

       SEARCH_REGEX
           Do a regular expression match of the search string against the value.

       SEARCH_NOCASE
           Ignore case when matching strings. Works for all the above match types.

       SEARCH_FILES
           Match the complete filenames of the file list, not just the base name.

       SEARCH_COMPLETE_FILELIST
           When matching the file list, check every file of the package not just the subset from
           the primary metadata.

       SEARCH_CHECKSUMS
           Allow the matching of checksum entries.

   METHODS
           void prepend_keyname(Id keyname);
           $di->prepend_keyname($keyname);
           di.prepend_keyname(keyname)
           di.prepend_keyname(keyname)

       Do a sub-search in the array stored in keyname.

           void skip_solvable();
           $di->skip_solvable();
           di.skip_solvable()
           di.skip_solvable()

       Stop matching the current solvable and advance to the next one.

           <iteration>
           for my $d (@$di)
           for d in di:
           for d in di

       Iterate through the matches. If there is a match, the object in d will be of type
       Datamatch.

THE DATAMATCH CLASS

       Objects of this type will be created for every value matched by a dataiterator.

   ATTRIBUTES
           Pool *pool;                             /* read only */
           $d->{pool}
           d.pool
           d.pool

       Back pointer to pool.

           Repo *repo;                             /* read only */
           $d->{repo}
           d.repo
           d.repo

       The repository containing the matched object.

           Solvable *solvable;                     /* read only */
           $d->{solvable}
           d.solvable
           d.solvable

       The solvable containing the value that was matched.

           Id solvid;                              /* read only */
           $d->{solvid}
           d.solvid
           d.solvid

       The id of the solvable that matched.

           Id key_id;
           $d->{key_id}
           d.key_id
           d.key_id

           const char *key_idstr;
           $d->{key_idstr}
           d.key_idstr
           d.key_idstr

       The keyname that matched, either as id or string.

           Id type_id;
           $d->{type_id}
           d.type_id
           d.type_id

           const char *type_idstr;
           $d->{type_idstr};
           d.type_idstr
           d.type_idstr

       The key type of the value that was matched, either as id or string.

           Id id;
           $d->{id}
           d.id
           d.id

           Id idstr;
           $d->{idstr}
           d.idstr
           d.idstr

       The Id of the value that was matched (only valid for id types), either as id or string.

           const char *str;
           $d->{str}
           d.str
           d.str

       The string value that was matched (only valid for string types).

           unsigned long long num;
           $d->{num}
           d.num
           d.num

       The numeric value that was matched (only valid for numeric types).

           unsigned int num2;
           $d->{num2}
           d.num2
           d.num2

       The secondary numeric value that was matched (only valid for types containing two values).

           unsigned int binary;
           $d->{binary}
           d.binary
           d.binary

       The value in binary form, useful for checksums and other data that cannot be represented
       as a string.

   METHODS
           Datapos pos()
           my $pos = $d->pos();
           pos = d.pos()
           pos = d.pos()

       The position object of the current match. It can be used to do sub-searches starting at
       the match (if it is of an array type). See the Datapos class for more information.

           Datapos parentpos()
           my $pos = $d->parentpos();
           pos = d.parentpos()
           pos = d.parentpos()

       The position object of the array containing the current match. It can be used to do
       sub-searches, see the Datapos class for more information.

           <stringification>
           my $str = $d->str;
           str = str(d)
           str = d.to_s

       Return the stringification of the matched value. Stringification depends on the search
       flags, for file list entries it will return just the base name unless SEARCH_FILES is
       used, for checksums it will return an empty string unless SEARCH_CHECKSUMS is used.
       Numeric values are currently stringified to an empty string.

THE SELECTION CLASS

       Selections are a way to easily deal with sets of packages. There are multiple constructors
       to create them, the most useful is probably the select() method in the Pool class.

   CONSTANTS
       SELECTION_NAME
           Create the selection by matching package names.

       SELECTION_PROVIDES
           Create the selection by matching package provides.

       SELECTION_FILELIST
           Create the selection by matching package files.

       SELECTION_CANON
           Create the selection by matching the canonical representation of the package. This is
           normally a combination of the name, the version, and the architecture of a package.

       SELECTION_DOTARCH
           Allow an ".<architecture>" suffix when matching names or provides.

       SELECTION_REL
           Allow the specification of a relation when matching names or dependencies, e.g. "name
           >= 1.2".

       SELECTION_GLOB
           Allow glob matching for package names, package provides, and file names.

       SELECTION_NOCASE
           Ignore case when matching package names, package provides, and file names.

       SELECTION_FLAT
           Return only one selection element describing the selected packages. The default is to
           create multiple elements for all globbed packages. Multiple elements are useful if you
           want to turn the selection into an install job, in that case you want an install job
           for every globbed package.

       SELECTION_SKIP_KIND
           Remove a "packagekind:" prefix from the package names.

       SELECTION_MATCH_DEPSTR
           When matching dependencies, do a string match on the result of dep2str instead of
           using the normal dependency intersect algorithm.

       SELECTION_INSTALLED_ONLY
           Limit the package search to installed packages.

       SELECTION_SOURCE_ONLY
           Limit the package search to source packages only.

       SELECTION_WITH_SOURCE
           Extend the package search to also match source packages. The default is only to match
           binary packages.

       SELECTION_WITH_DISABLED
           Extend the package search to also include disabled packages.

       SELECTION_WITH_BADARCH
           Extend the package search to also include packages that are not installable on the
           configured architecture.

       SELECTION_WITH_ALL
           Shortcut for selecting the three modifiers above.

       SELECTION_ADD
           Add the result of the match to the current selection instead of replacing it.

       SELECTION_SUBTRACT
           Remove the result of the match to the current selection instead of replacing it.

       SELECTION_FILTER
           Intersect the result of the match to the current selection instead of replacing it.

   ATTRIBUTES
           Pool *pool;                             /* read only */
           $d->{pool}
           d.pool
           d.pool

       Back pointer to pool.

           int flags;                              /* read only */
           $sel->{flags}
           flags = sel.flags
           flags = sel.flags

       The result flags of the selection. The flags are a subset of the ones used when creating
       the selection, they describe which method was used to get the result. For example, if you
       create the selection with “SELECTION_NAME | SELECTION_PROVIDES”, the resulting flags will
       either be SELECTION_NAME or SELECTION_PROVIDES depending if there was a package that
       matched the name or not. If there was no match at all, the flags will be zero.

   METHODS
           bool isempty()
           $sel->isempty()
           sel.isempty()
           sel.isempty?

       Return true if the selection is empty, i.e. no package could be matched.

           Selection clone(int flags = 0)
           my $cloned = $sel->clone();
           cloned = sel.clone()
           cloned = sel.clone()

       Return a copy of a selection.

           void filter(Selection *other)
           $sel->filter($other);
           sel.filter(other)
           sel.filter(other)

       Intersect two selections. Packages will only stay in the selection if there are also
       included in the other selecting. Does an in-place modification.

           void add(Selection *other)
           $sel->add($other);
           sel.add(other)
           sel.add(other)

       Build the union of two selections. All packages of the other selection will be added to
       the set of packages of the selection object. Does an in-place modification. Note that the
       selection flags are no longer meaningful after the add operation.

           void subtract(Selection *other)
           $sel->subtract($other);
           sel.subtract(other)
           sel.subtract(other)

       Remove the packages of the other selection from the packages of the selection object. Does
       an in-place modification.

           void add_raw(Id how, Id what)
           $sel->add_raw($how, $what);
           sel.add_raw(how, what)
           sel.add_raw(how, what)

       Add a raw element to the selection. Check the Job class for information about the how and
       what parameters. Note that the selection flags are no longer meaningful after the add_raw
       operation.

           Job *jobs(int action)
           my @jobs = $sel->jobs($action);
           jobs = sel.jobs(action)
           jobs = sel.jobs(action)

       Convert a selection into an array of Job objects. The action parameter is or-ed to the
       “how” part of the job, it describes the type of job (e.g. install, erase). See the Job
       class for the action and action modifier constants.

           Solvable *solvables()
           my @solvables = $sel->solvables();
           solvables = sel.solvables()
           solvables = sel.solvables()

       Convert a selection into an array of Solvable objects.

           void select(const char *name, int flags)
           $sel->select($name, $flags);
           sel.select(name, flags)
           sel.select(name, flags)

       Do a select operation and combine the result with the current selection. You can choose
       the desired combination method by using either the SELECTION_ADD, SELECTION_SUBTRACT, or
       SELECTION_FILTER flag. If none of the flags are used, SELECTION_FILTER|SELECTION_WITH_ALL
       is assumed.

           void matchdeps(const char *name, int flags, Id keyname, Id marker = -1)
           $sel->matchdeps($name, $flags, $keyname);
           sel.matchdeps(name, flags, keyname)
           sel.matchdeps(name, flags, keyname)

       Do a matchdeps operation and combine the result with the current selection.

           void matchdepid(DepId dep, int flags, Id keyname, Id marker = -1)
           $sel->matchdepid($dep, $flags, $keyname);
           sel.matchdepid(dep, flags, keyname)
           sel.matchdepid(dep, flags, keyname)

       Do a matchdepid operation and combine the result with the current selection.

           void matchsolvable(Solvable solvable, int flags, Id keyname, Id marker = -1)
           $sel->matchsolvable($solvable, $flags, $keyname);
           sel.matchsolvable(solvable, flags, keyname)
           sel.matchsolvable(solvable, flags, keyname)

       Do a matchsolvable operation and combine the result with the current selection.

           <stringification>
           my $str = $sel->str;
           str = str(sel)
           str = sel.to_s

       Return a string describing the selection.

THE JOB CLASS

       Jobs are the way to specify to the dependency solver what to do. Most of the times jobs
       will get created by calling the jobs() method on a Selection object, but there is also a
       Job() constructor in the Pool class.

   CONSTANTS
       Selection constants:

       SOLVER_SOLVABLE
           The “what” part is the id of a solvable.

       SOLVER_SOLVABLE_NAME
           The “what” part is the id of a package name.

       SOLVER_SOLVABLE_PROVIDES
           The “what” part is the id of a package provides.

       SOLVER_SOLVABLE_ONE_OF
           The “what” part is an offset into the “whatprovides” data, created by calling the
           towhatprovides() pool method.

       SOLVER_SOLVABLE_REPO
           The “what” part is the id of a repository.

       SOLVER_SOLVABLE_ALL
           The “what” part is ignored, all packages are selected.

       SOLVER_SOLVABLE_SELECTMASK
           A mask containing all the above selection bits.

       Action constants:

       SOLVER_NOOP
           Do nothing.

       SOLVER_INSTALL
           Install a package of the specified set of packages. It tries to install the best
           matching package (i.e. the highest version of the packages from the repositories with
           the highest priority).

       SOLVER_ERASE
           Erase all of the packages from the specified set. If a package is not installed,
           erasing it will keep it from getting installed.

       SOLVER_UPDATE
           Update the matching installed packages to their best version. If none of the specified
           packages are installed, try to update the installed packages to the specified
           versions. See the section about targeted updates about more information.

       SOLVER_WEAKENDEPS
           Allow one to break the dependencies of the matching packages. Handle with care.

       SOLVER_MULTIVERSION
           Mark the matched packages for multiversion install. If they get to be installed
           because of some other job, the installation will keep the old version of the package
           installed (for rpm this is done by using “-i” instead of “-U”).

       SOLVER_LOCK
           Do not change the state of the matched packages, i.e. when they are installed they
           stay installed, if not they are not selected for installation.

       SOLVER_DISTUPGRADE
           Update the matching installed packages to the best version included in one of the
           repositories. After this operation, all come from one of the available repositories
           except orphaned packages. Orphaned packages are packages that have no relation to the
           packages in the repositories, i.e. no package in the repositories have the same name
           or obsolete the orphaned package. This action brings the installed packages in sync
           with the ones in the repository. By default it also turns of arch/vendor/version
           locking for the affected packages to simulate a fresh installation. This means that
           distupgrade can actually downgrade packages if only lower versions of a package are
           available in the repositories. You can tweak this behavior with the SOLVER_FLAG_DUP_
           solver flags.

       SOLVER_DROP_ORPHANED
           Erase all the matching installed packages if they are orphaned. This only makes sense
           if there is a “distupgrade all packages” job. The default is to erase orphaned
           packages only if they block the installation of other packages.

       SOLVER_VERIFY
           Fix dependency problems of matching installed packages. The default is to ignore
           dependency problems for installed packages.

       SOLVER_USERINSTALLED
           The matching installed packages are considered to be installed by a user, thus not
           installed to fulfill some dependency. This is needed input for the calculation of
           unneeded packages for jobs that have the SOLVER_CLEANDEPS flag set.

       SOLVER_ALLOWUNINSTALL
           Allow the solver to deinstall the matching installed packages if they get into the way
           of resolving a dependency. This is like the SOLVER_FLAG_ALLOW_UNINSTALL flag, but
           limited to a specific set of packages.

       SOLVER_FAVOR
           Prefer the specified packages if the solver encounters an alternative. If a job
           contains multiple matching favor/disfavor elements, the last one takes precedence.

       SOLVER_DISFAVOR
           Avoid the specified packages if the solver encounters an alternative. This can also be
           used to block recommended or supplemented packages from being installed.

       SOLVER_EXCLUDEFROMWEAK
           Avoid the specified packages to satisfy recommended or supplemented dependencies.
           Unlike SOLVER_DISFAVOR, it does not interfere with other rules.

       SOLVER_JOBMASK
           A mask containing all the above action bits.

       Action modifier constants:

       SOLVER_WEAK
           Makes the job a weak job. The solver tries to fulfill weak jobs, but does not report a
           problem if it is not possible to do so.

       SOLVER_ESSENTIAL
           Makes the job an essential job. If there is a problem with the job, the solver will
           not propose to remove the job as one solution (unless all other solutions are also to
           remove essential jobs).

       SOLVER_CLEANDEPS
           The solver will try to also erase all packages dragged in through dependencies when
           erasing the package. This needs SOLVER_USERINSTALLED jobs to maximize user
           satisfaction.

       SOLVER_FORCEBEST
           Insist on the best package for install, update, and distupgrade jobs. If this flag is
           not used, the solver will use the second-best package if the best package cannot be
           installed for some reason. When this flag is used, the solver will generate a problem
           instead.

       SOLVER_TARGETED
           Forces targeted operation update and distupgrade jobs. See the section about targeted
           updates about more information.

       Set constants.

       SOLVER_SETEV
           The job specified the exact epoch and version of the package set.

       SOLVER_SETEVR
           The job specified the exact epoch, version, and release of the package set.

       SOLVER_SETARCH
           The job specified the exact architecture of the packages from the set.

       SOLVER_SETVENDOR
           The job specified the exact vendor of the packages from the set.

       SOLVER_SETREPO
           The job specified the exact repository of the packages from the set.

       SOLVER_SETNAME
           The job specified the exact name of the packages from the set.

       SOLVER_NOAUTOSET
           Turn of automatic set flag generation for SOLVER_SOLVABLE jobs.

       SOLVER_SETMASK
           A mask containing all the above set bits.

       See the section about set bits for more information.

   ATTRIBUTES
           Pool *pool;                             /* read only */
           $job->{pool}
           d.pool
           d.pool

       Back pointer to pool.

           Id how;                                 /* read/write */
           $job->{how}
           d.how
           d.how

       Union of the selection, action, action modifier, and set flags. The selection part
       describes the semantics of the “what” Id.

           Id what;                                /* read/write */
           $job->{what}
           d.what
           d.what

       Id describing the set of packages, the meaning depends on the selection part of the “how”
       attribute.

   METHODS
           Solvable *solvables()
           my @solvables = $job->solvables();
           solvables = job.solvables()
           solvables = job.solvables()

       Return the set of solvables of the job as an array of Solvable objects.

           bool isemptyupdate()
           $job->isemptyupdate()
           job.isemptyupdate()
           job.isemptyupdate?

       Convenience function to find out if the job describes an update job with no matching
       packages, i.e. a job that does nothing. Some package managers like “zypper” like to turn
       those jobs into install jobs, i.e. an update of a not-installed package will result into
       the installation of the package.

           <stringification>
           my $str = $job->str;
           str = str(job)
           str = job.to_s

       Return a string describing the job.

           <equality>
           if ($job1 == $job2)
           if job1 == job2:
           if job1 == job2

       Two jobs are equal if they belong to the same pool and both the “how” and the “what”
       attributes are the same.

   TARGETED UPDATES
       Libsolv has two modes for upgrades and distupgrade: targeted and untargeted. Untargeted
       mode means that the installed packages from the specified set will be updated to the best
       version. Targeted means that packages that can be updated to a package in the specified
       set will be updated to the best package of the set.

       Here’s an example to explain the subtle difference. Suppose that you have package A
       installed in version "1.1", "A-1.2" is available in one of the repositories and there is
       also package "B" that obsoletes package A.

       An untargeted update of "A" will update the installed "A-1.1" to package "B", because that
       is the newest version (B obsoletes A and is thus newer).

       A targeted update of "A" will update "A-1.1" to "A-1.2", as the set of packages contains
       both "A-1.1" and "A-1.2", and "A-1.2" is the newer one.

       An untargeted update of "B" will do nothing, as "B" is not installed.

       An targeted update of "B" will update "A-1.1" to "B".

       Note that the default is to do "auto-targeting", thus if the specified set of packages
       does not include an installed package, the solver will assume targeted operation even if
       SOLVER_TARGETED is not used.

       This mostly matches the intent of the user, with one exception: In the example above, an
       update of "A-1.2" will update "A-1.1" to "A-1.2" (targeted mode), but a second update of
       "A-1.2" will suddenly update to "B", as untargeted mode is chosen because "A-1.2" is now
       installed.

       If you want to have full control over when targeting mode is chosen, turn off
       auto-targeting with the SOLVER_FLAG_NO_AUTOTARGET solver option. In that case, all updates
       are considered to be untargeted unless they include the SOLVER_TARGETED flag.

   SET BITS
       Set bits specify which parts of the specified packages where specified by the user. It is
       used by the solver when checking if an operation is allowed or not. For example, the
       solver will normally not allow the downgrade of an installed package. But it will not
       report a problem if the SOLVER_SETEVR flag is used, as it then assumes that the user
       specified the exact version and thus knows what he is doing.

       So if a package "screen-1-1" is installed for the x86_64 architecture and version "2-1" is
       only available for the i586 architecture, installing package "screen-2.1" will ask the
       user for confirmation because of the different architecture. When using the Selection
       class to create jobs the set bits are automatically added, e.g. selecting “screen.i586”
       will automatically add SOLVER_SETARCH, and thus no problem will be reported.

THE SOLVER CLASS

       Dependency solving is what this library is about. A solver object is needed for solving to
       store the result of the solver run. The solver object can be used multiple times for
       different jobs, reusing it allows the solver to re-use the dependency rules it already
       computed.

   CONSTANTS
       Flags to modify some of the solver’s behavior:

       SOLVER_FLAG_ALLOW_DOWNGRADE
           Allow the solver to downgrade packages without asking for confirmation (i.e. reporting
           a problem).

       SOLVER_FLAG_ALLOW_ARCHCHANGE
           Allow the solver to change the architecture of an installed package without asking for
           confirmation. Note that changes to/from noarch are always considered to be allowed.

       SOLVER_FLAG_ALLOW_VENDORCHANGE
           Allow the solver to change the vendor of an installed package without asking for
           confirmation. Each vendor is part of one or more vendor equivalence classes, normally
           installed packages may only change their vendor if the new vendor shares at least one
           equivalence class.

       SOLVER_FLAG_ALLOW_NAMECHANGE
           Allow the solver to change the name of an installed package, i.e. install a package
           with a different name that obsoletes the installed package. This option is on by
           default.

       SOLVER_FLAG_ALLOW_UNINSTALL
           Allow the solver to erase installed packages to fulfill the jobs. This flag also
           includes the above flags. You may want to set this flag if you only have SOLVER_ERASE
           jobs, as in that case it’s better for the user to check the transaction overview
           instead of approving every single package that needs to be erased.

       SOLVER_FLAG_DUP_ALLOW_DOWNGRADE
           Like SOLVER_FLAG_ALLOW_DOWNGRADE, but used in distupgrade mode.

       SOLVER_FLAG_DUP_ALLOW_ARCHCHANGE
           Like SOLVER_FLAG_ALLOW_ARCHCHANGE, but used in distupgrade mode.

       SOLVER_FLAG_DUP_ALLOW_VENDORCHANGE
           Like SOLVER_FLAG_ALLOW_VENDORCHANGE, but used in distupgrade mode.

       SOLVER_FLAG_DUP_ALLOW_NAMECHANGE
           Like SOLVER_FLAG_ALLOW_NAMECHANGE, but used in distupgrade mode.

       SOLVER_FLAG_NO_UPDATEPROVIDE
           If multiple packages obsolete an installed package, the solver checks the provides of
           every such package and ignores all packages that do not provide the installed package
           name. Thus, you can have an official update candidate that provides the old name, and
           other packages that also obsolete the package but are not considered for updating. If
           you cannot use this feature, you can turn it off by setting this flag.

       SOLVER_FLAG_NEED_UPDATEPROVIDE
           This is somewhat the opposite of SOLVER_FLAG_NO_UPDATEPROVIDE: Only packages that
           provide the installed package names are considered for updating.

       SOLVER_FLAG_SPLITPROVIDES
           Make the solver aware of special provides of the form “<packagename>:<path>” used in
           SUSE systems to support package splits.

       SOLVER_FLAG_IGNORE_RECOMMENDED
           Do not process optional (aka weak) dependencies.

       SOLVER_FLAG_ADD_ALREADY_RECOMMENDED
           Install recommended or supplemented packages even if they have no connection to the
           current transaction. You can use this feature to implement a simple way for the user
           to install new recommended packages that were not available in the past.

       SOLVER_FLAG_NO_INFARCHCHECK
           Turn off the inferior architecture checking that is normally done by the solver.
           Normally, the solver allows only the installation of packages from the "best"
           architecture if a package is available for multiple architectures.

       SOLVER_FLAG_BEST_OBEY_POLICY
           Make the SOLVER_FORCEBEST job option consider only packages that meet the policies for
           installed packages, i.e. no downgrades, no architecture change, no vendor change (see
           the first flags of this section). If the flag is not specified, the solver will
           enforce the installation of the best package ignoring the installed packages, which
           may conflict with the set policy.

       SOLVER_FLAG_NO_AUTOTARGET
           Do not enable auto-targeting up update and distupgrade jobs. See the section on
           targeted updates for more information.

       SOLVER_FLAG_KEEP_ORPHANS
           Do not allow orphaned packages to be deinstalled if they get in the way of resolving
           other packages.

       SOLVER_FLAG_BREAK_ORPHANS
           Ignore dependencies of orphaned packages that get in the way of resolving non-orphaned
           ones. Setting the flag might result in no longer working packages in case they are
           orphaned.

       SOLVER_FLAG_FOCUS_INSTALLED
           Resolve installed packages before resolving the given jobs. Setting this flag means
           that the solver will prefer picking a package version that fits the other installed
           packages over updating installed packages.

       SOLVER_FLAG_FOCUS_BEST
           First resolve the given jobs, then the dependencies of the resulting packages, then
           resolve all already installed packages. This will result in more packages being
           updated as when the flag is not used.

       SOLVER_FLAG_INSTALL_ALSO_UPDATES
           Update the package if a job is already fulfilled by an installed package.

       SOLVER_FLAG_YUM_OBSOLETES
           Turn on yum-like package split handling. See the yum documentation for more details.

       SOLVER_FLAG_URPM_REORDER
           Turn on urpm like package reordering for kernel packages. See the urpm documentation
           for more details.

       Basic rule types:

       SOLVER_RULE_UNKNOWN
           A rule of an unknown class. You should never encounter those.

       SOLVER_RULE_PKG
           A rule generated because of a package dependency.

       SOLVER_RULE_UPDATE
           A rule to implement the update policy of installed packages. Every installed package
           has an update rule that consists of the packages that may replace the installed
           package.

       SOLVER_RULE_FEATURE
           Feature rules are fallback rules used when an update rule is disabled. They include
           all packages that may replace the installed package ignoring the update policy, i.e.
           they contain downgrades, arch changes and so on. Without them, the solver would simply
           erase installed packages if their update rule gets disabled.

       SOLVER_RULE_JOB
           Job rules implement the job given to the solver.

       SOLVER_RULE_DISTUPGRADE
           These are simple negative assertions that make sure that only packages are kept that
           are also available in one of the repositories.

       SOLVER_RULE_INFARCH
           Infarch rules are also negative assertions, they disallow the installation of packages
           when there are packages of the same name but with a better architecture.

       SOLVER_RULE_CHOICE
           Choice rules are used to make sure that the solver prefers updating to installing
           different packages when some dependency is provided by multiple packages with
           different names. The solver may always break choice rules, so you will not see them
           when a problem is found.

       SOLVER_RULE_LEARNT
           These rules are generated by the solver to keep it from running into the same problem
           multiple times when it has to backtrack. They are the main reason why a sat solver is
           faster than other dependency solver implementations.

       Special dependency rule types:

       SOLVER_RULE_PKG_NOT_INSTALLABLE
           This rule was added to prevent the installation of a package of an architecture that
           does not work on the system.

       SOLVER_RULE_PKG_NOTHING_PROVIDES_DEP
           The package contains a required dependency which was not provided by any package.

       SOLVER_RULE_PKG_REQUIRES
           The package contains a required dependency which was provided by at least one package.

       SOLVER_RULE_PKG_SELF_CONFLICT
           The package conflicts with itself. This is not allowed by older rpm versions.

       SOLVER_RULE_PKG_CONFLICTS
           The package conflices with some other package.

       SOLVER_RULE_PKG_SAME_NAME
           This rules make sure that only one version of a package is installed in the system.

       SOLVER_RULE_PKG_OBSOLETES
           To fulfill the dependencies two packages need to be installed, but one of the packages
           obsoletes the other one.

       SOLVER_RULE_PKG_IMPLICIT_OBSOLETES
           To fulfill the dependencies two packages need to be installed, but one of the packages
           has provides a dependency that is obsoleted by the other one. See the
           POOL_FLAG_IMPLICITOBSOLETEUSESPROVIDES flag.

       SOLVER_RULE_PKG_INSTALLED_OBSOLETES
           To fulfill the dependencies a package needs to be installed that is obsoleted by an
           installed package. See the POOL_FLAG_NOINSTALLEDOBSOLETES flag.

       SOLVER_RULE_PKG_RECOMMENDS
           The package contains a recommended dependency.

       SOLVER_RULE_PKG_SUPPLEMENTS
           The package contains a dependency to specify it supplements another package.

       SOLVER_RULE_PKG_CONSTRAINS
           The package contains a constraint against some other package (disttype conda).

       SOLVER_RULE_JOB_NOTHING_PROVIDES_DEP
           The user asked for installation of a package providing a specific dependency, but no
           available package provides it.

       SOLVER_RULE_JOB_UNKNOWN_PACKAGE
           The user asked for installation of a package with a specific name, but no available
           package has that name.

       SOLVER_RULE_JOB_PROVIDED_BY_SYSTEM
           The user asked for the erasure of a dependency that is provided by the system (i.e.
           for special hardware or language dependencies), this cannot be done with a job.

       SOLVER_RULE_JOB_UNSUPPORTED
           The user asked for something that is not yet implemented, e.g. the installation of all
           packages at once.

       Policy error constants

       POLICY_ILLEGAL_DOWNGRADE
           The solver ask for permission before downgrading packages.

       POLICY_ILLEGAL_ARCHCHANGE
           The solver ask for permission before changing the architecture of installed packages.

       POLICY_ILLEGAL_VENDORCHANGE
           The solver ask for permission before changing the vendor of installed packages.

       POLICY_ILLEGAL_NAMECHANGE
           The solver ask for permission before replacing an installed packages with a package
           that has a different name.

       Solution element type constants

       SOLVER_SOLUTION_JOB
           The problem can be solved by removing the specified job.

       SOLVER_SOLUTION_POOLJOB
           The problem can be solved by removing the specified job that is defined in the pool.

       SOLVER_SOLUTION_INFARCH
           The problem can be solved by allowing the installation of the specified package with
           an inferior architecture.

       SOLVER_SOLUTION_DISTUPGRADE
           The problem can be solved by allowing to keep the specified package installed.

       SOLVER_SOLUTION_BEST
           The problem can be solved by allowing to install the specified package that is not the
           best available package.

       SOLVER_SOLUTION_ERASE
           The problem can be solved by allowing to erase the specified package.

       SOLVER_SOLUTION_REPLACE
           The problem can be solved by allowing to replace the package with some other package.

       SOLVER_SOLUTION_REPLACE_DOWNGRADE
           The problem can be solved by allowing to replace the package with some other package
           that has a lower version.

       SOLVER_SOLUTION_REPLACE_ARCHCHANGE
           The problem can be solved by allowing to replace the package with some other package
           that has a different architecture.

       SOLVER_SOLUTION_REPLACE_VENDORCHANGE
           The problem can be solved by allowing to replace the package with some other package
           that has a different vendor.

       SOLVER_SOLUTION_REPLACE_NAMECHANGE
           The problem can be solved by allowing to replace the package with some other package
           that has a different name.

       Reason constants

       SOLVER_REASON_UNRELATED
           The package status did not change as it was not related to any job.

       SOLVER_REASON_UNIT_RULE
           The package was installed/erased/kept because of a unit rule, i.e. a rule where all
           literals but one were false.

       SOLVER_REASON_KEEP_INSTALLED
           The package was chosen when trying to keep as many packages installed as possible.

       SOLVER_REASON_RESOLVE_JOB
           The decision happened to fulfill a job rule.

       SOLVER_REASON_UPDATE_INSTALLED
           The decision happened to fulfill a package update request.

       SOLVER_REASON_CLEANDEPS_ERASE
           The package was erased when cleaning up dependencies from other erased packages.

       SOLVER_REASON_RESOLVE
           The package was installed to fulfill package dependencies.

       SOLVER_REASON_WEAKDEP
           The package was installed because of a weak dependency (Recommends or Supplements).

       SOLVER_REASON_RESOLVE_ORPHAN
           The decision about the package was made when deciding the fate of orphaned packages.

       SOLVER_REASON_RECOMMENDED
           This is a special case of SOLVER_REASON_WEAKDEP.

       SOLVER_REASON_SUPPLEMENTED
           This is a special case of SOLVER_REASON_WEAKDEP.

       SOLVER_REASON_UNSOLVABLE
           This is a special case where a rule cannot be fulfilled.

       SOLVER_REASON_PREMISE
           This is a special case for the premises of learnt rules.

   ATTRIBUTES
           Pool *pool;                             /* read only */
           $job->{pool}
           d.pool
           d.pool

       Back pointer to pool.

   METHODS
           int set_flag(int flag, int value)
           my $oldvalue = $solver->set_flag($flag, $value);
           oldvalue = solver.set_flag(flag, value)
           oldvalue = solver.set_flag(flag, value)

           int get_flag(int flag)
           my $value = $solver->get_flag($flag);
           value = solver.get_flag(flag)
           value = solver.get_flag(flag)

       Set/get a solver specific flag. The flags define the policies the solver has to obey. The
       flags are explained in the CONSTANTS section of this class.

           Problem *solve(Job *jobs)
           my @problems = $solver->solve(\@jobs);
           problems = solver.solve(jobs)
           problems = solver.solve(jobs)

       Solve a problem specified in the job list (plus the jobs defined in the pool). Returns an
       array of problems that need user interaction, or an empty array if no problems were
       encountered. See the Problem class on how to deal with problems.

           Transaction transaction()
           my $trans = $solver->transaction();
           trans = solver.transaction()
           trans = solver.transaction()

       Return the transaction to implement the calculated package changes. A transaction is
       available even if problems were found, this is useful for interactive user interfaces that
       show both the job result and the problems.

           Solvable *get_recommended(bool noselected=0)
           my @solvables = $solver->get_recommended();
           solvables = solver.get_recommended()
           solvables = solver.get_recommended()

       Return all solvables that are recommended by the solver run result. This includes
       solvables included in the result; set noselected if you want to filter those.

           Solvable *get_suggested(bool noselected=0)
           my @solvables = $solver->get_suggested();
           solvables = solver.get_suggested()
           solvables = solver.get_suggested()

       Return all solvables that are suggested by the solver run result. This includes solvables
       included in the result; set noselected if you want to filter those.

           Decision = get_decision(Solvable *s)
           my $decision = $solver->get_decision($solvable);
           decision = solver.get_decision(solvable);
           decision = solver.get_decision(solvable);

       Return a decision object that describes why a specific solvable was installed or erased.
       See the Decision class for more information.

           Decision *get_decisionlist(Solvable *s)
           my @decisions = $solver->get_decisionlist($solvable);
           decisions = solver.get_decisionlist(solvable)
           decisions = solver.get_decisionlist(solvable)

       Return a list of decisions that caused the specific solvable to be installed or erased.
       This is usually more useful than the get_decision() method, as it returns every involved
       decision instead of just a single one.

           Alternative *alternatives()
           my @alternatives = $solver->alternatives();
           alternatives = solver.alternatives()
           alternatives = solver.alternatives()

       Return all alternatives recorded in the solver run. See the Alternative class for more
       information.

           int alternatives_count()
           my $cnt = $solver->alternatives_count();
           cnt = solver.alternatives_count()
           cnt = solver.alternatives_count()

       Return the number of alternatives without creating alternative objects.

THE PROBLEM CLASS

       Problems are the way of the solver to interact with the user. You can simply list all
       problems and terminate your program, but a better way is to present solutions to the user
       and let him pick the ones he likes.

   ATTRIBUTES
           Solver *solv;                           /* read only */
           $problem->{solv}
           problem.solv
           problem.solv

       Back pointer to solver object.

           Id id;                                  /* read only */
           $problem->{id}
           problem.id
           problem.id

       Id of the problem. The first problem has Id 1, they are numbered consecutively.

   METHODS
           Rule findproblemrule()
           my $probrule = $problem->findproblemrule();
           probrule = problem.findproblemrule()
           probrule = problem.findproblemrule()

       Return the rule that caused the problem. Of course in most situations there is no single
       responsible rule, but many rules that interconnect with each created the problem.
       Nevertheless, the solver uses some heuristic approach to find a rule that somewhat
       describes the problem best to the user.

           Rule *findallproblemrules(bool unfiltered = 0)
           my @probrules = $problem->findallproblemrules();
           probrules = problem.findallproblemrules()
           probrules = problem.findallproblemrules()

       Return all rules responsible for the problem. The returned set of rules contains all the
       needed information why there was a problem, but it’s hard to present them to the user in a
       sensible way. The default is to filter out all update and job rules (unless the returned
       rules only consist of those types).

           Decision *get_decisionlist()
           my @decisions = $problem->get_decisionlist();
           decisions = problem.get_decisionlist()
           decisions = problem.get_decisionlist()

       Return a list of decisions prooving the problem. This is somewhat similar to the
       findallproblemrules(), but the output is in an order that makes it easier to understand
       why the solver could not find a solution.

           Decisionset *get_decisionsetlist()
           my @decisionsets = $problem->get_decisionsetlist();
           decisionsets = problem.get_decisionsetlist()
           decisionsets = problem.get_decisionsetlist()

       Like the get_decisionlist() method, but the decisions are merged into individual sets.

           Rule *get_learnt()
           my @learnt = $problem->get_learnt();
           learnt = problem.get_learnt()
           learnt = problem.get_lerant()

       Return a list of learnt rules that are part of the problem proof. This is useful for
       presenting a complete proof to the user.

           Solution *solutions()
           my @solutions = $problem->solutions();
           solutions = problem.solutions()
           solutions = problem.solutions()

       Return an array containing multiple possible solutions to fix the problem. See the
       solution class for more information.

           int solution_count()
           my $cnt = $problem->solution_count();
           cnt = problem.solution_count()
           cnt = problem.solution_count()

       Return the number of solutions without creating solution objects.

           <stringification>
           my $str = $problem->str;
           str = str(problem)
           str = problem.to_s

       Return a string describing the problem. This is a convenience function, it is a shorthand
       for calling findproblemrule(), then ruleinfo() on the problem rule and problemstr() on the
       ruleinfo object.

THE RULE CLASS

       Rules are the basic block of sat solving. Each package dependency gets translated into one
       or multiple rules.

   ATTRIBUTES
           Solver *solv;                           /* read only */
           $rule->{solv}
           rule.solv
           rule.solv

       Back pointer to solver object.

           Id id;                                  /* read only */
           $rule->{id}
           rule.id
           rule.id

       The id of the rule.

           int type;                               /* read only */
           $rule->{type}
           rule.type
           rule.type

       The basic type of the rule. See the constant section of the solver class for the type
       list.

   METHODS
           Ruleinfo info()
           my $ruleinfo = $rule->info();
           ruleinfo = rule.info()
           ruleinfo = rule.info()

       Return a Ruleinfo object that contains information about why the rule was created. But see
       the allinfos() method below.

           Ruleinfo *allinfos()
           my @ruleinfos = $rule->allinfos();
           ruleinfos = rule.allinfos()
           ruleinfos = rule.allinfos()

       As the same dependency rule can get created because of multiple dependencies, one Ruleinfo
       is not enough to describe the reason. Thus the allinfos() method returns an array of all
       infos about a rule.

           Decision *get_decisionlist()
           my @decisions = $rule->get_decisionlist();
           decisions = rule.get_decisionlist()
           decisions = rule.get_decisionlist()

       Return a list of decisions prooving a learnt rule.

           Decision *get_decisionsetlist()
           my @decisionsets = $rule->get_decisionsetlist();
           decisionsets = rule.get_decisionsetlist()
           decisionsets = rule.get_decisionsetlist()

       Like the get_decisionlist() method, but the decisions are merged into individual sets.

           Rule *get_learnt()
           my @learnt = $rule->get_learnt();
           learnt = rule.get_learnt()
           learnt = rule.get_lerant()

       Return a list of learnt rules that are part of the learnt rule proof.

           <equality>
           if ($rule1 == $rule2)
           if rule1 == rule2:
           if rule1 == rule2

       Two rules are equal if they belong to the same solver and have the same id.

THE RULEINFO CLASS

       A Ruleinfo describes one reason why a rule was created.

   ATTRIBUTES
           Solver *solv;                           /* read only */
           $ruleinfo->{solv}
           ruleinfo.solv
           ruleinfo.solv

       Back pointer to solver object.

           int type;                               /* read only */
           $ruleinfo->{type}
           ruleinfo.type
           ruleinfo.type

       The type of the ruleinfo. See the constant section of the solver class for the rule type
       list and the special type list.

           Dep *dep;                               /* read only */
           $ruleinfo->{dep}
           ruleinfo.dep
           ruleinfo.dep

       The dependency leading to the creation of the rule.

           Dep *dep_id;                            /* read only */
           $ruleinfo->{dep_id}
           ruleinfo.dep_id
           ruleinfo.dep_id

       The Id of the dependency leading to the creation of the rule, or zero.

           Solvable *solvable;                     /* read only */
           $ruleinfo->{solvable}
           ruleinfo.solvable
           ruleinfo.solvable

       The involved Solvable, e.g. the one containing the dependency.

           Solvable *othersolvable;                /* read only */
           $ruleinfo->{othersolvable}
           ruleinfo.othersolvable
           ruleinfo.othersolvable

       The other involved Solvable (if any), e.g. the one providing the dependency.

           const char *problemstr();
           my $str = $ruleinfo->problemstr();
           str = ruleinfo.problemstr()
           str = ruleinfo.problemstr()

       A string describing the ruleinfo from a problem perspective. This probably only makes
       sense if the rule is part of a problem.

           <stringification>
           my $str = $ruleinfo->str;
           str = str(ruleinfo)
           str = ruleinfo.to_s

       A string describing the ruleinfo, i.e. the reason why the corresponding rule has been
       created.

THE SOLUTION CLASS

       A solution solves one specific problem. It consists of multiple solution elements that all
       need to be executed.

   ATTRIBUTES
           Solver *solv;                           /* read only */
           $solution->{solv}
           solution.solv
           solution.solv

       Back pointer to solver object.

           Id problemid;                           /* read only */
           $solution->{problemid}
           solution.problemid
           solution.problemid

       Id of the problem the solution solves.

           Id id;                                  /* read only */
           $solution->{id}
           solution.id
           solution.id

       Id of the solution. The first solution has Id 1, they are numbered consecutively.

   METHODS
           Solutionelement *elements(bool expandreplaces = 0)
           my @solutionelements = $solution->elements();
           solutionelements = solution.elements()
           solutionelements = solution.elements()

       Return an array containing the elements describing what needs to be done to implement the
       specific solution. If expandreplaces is true, elements of type SOLVER_SOLUTION_REPLACE
       will be replaced by one or more elements replace elements describing the policy
       mismatches.

           int element_count()
           my $cnt = $solution->solution_count();
           cnt = solution.element_count()
           cnt = solution.element_count()

       Return the number of solution elements without creating objects. Note that the count does
       not match the number of objects returned by the elements() method of expandreplaces is set
       to true.

THE SOLUTIONELEMENT CLASS

       A solution element describes a single action of a solution. The action is always either to
       remove one specific job or to add a new job that installs or erases a single specific
       package.

   ATTRIBUTES
           Solver *solv;                           /* read only */
           $solutionelement->{solv}
           solutionelement.solv
           solutionelement.solv

       Back pointer to solver object.

           Id problemid;                           /* read only */
           $solutionelement->{problemid}
           solutionelement.problemid
           solutionelement.problemid

       Id of the problem the element (partly) solves.

           Id solutionid;                          /* read only */
           $solutionelement->{solutionid}
           solutionelement.solutionid
           solutionelement.solutionid

       Id of the solution the element is a part of.

           Id id;                                  /* read only */
           $solutionelement->{id}
           solutionelement.id
           solutionelement.id

       Id of the solution element. The first element has Id 1, they are numbered consecutively.

           Id type;                                /* read only */
           $solutionelement->{type}
           solutionelement.type
           solutionelement.type

       Type of the solution element. See the constant section of the solver class for the
       existing types.

           Solvable *solvable;                     /* read only */
           $solutionelement->{solvable}
           solutionelement.solvable
           solutionelement.solvable

       The installed solvable that needs to be replaced for replacement elements.

           Solvable *replacement;                  /* read only */
           $solutionelement->{replacement}
           solutionelement.replacement
           solutionelement.replacement

       The solvable that needs to be installed to fix the problem.

           int jobidx;                             /* read only */
           $solutionelement->{jobidx}
           solutionelement.jobidx
           solutionelement.jobidx

       The index of the job that needs to be removed to fix the problem, or -1 if the element is
       of another type. Note that it’s better to change the job to SOLVER_NOOP type so that the
       numbering of other elements does not get disturbed. This method works both for types
       SOLVER_SOLUTION_JOB and SOLVER_SOLUTION_POOLJOB.

   METHODS
           Solutionelement *replaceelements()
           my @solutionelements = $solutionelement->replaceelements();
           solutionelements = solutionelement.replaceelements()
           solutionelements = solutionelement.replaceelements()

       If the solution element is of type SOLVER_SOLUTION_REPLACE, return an array of elements
       describing the policy mismatches, otherwise return a copy of the element. See also the
       “expandreplaces” option in the solution’s elements() method.

           int illegalreplace()
           my $illegal = $solutionelement->illegalreplace();
           illegal = solutionelement.illegalreplace()
           illegal = solutionelement.illegalreplace()

       Return an integer that contains the policy mismatch bits or-ed together, or zero if there
       was no policy mismatch. See the policy error constants in the solver class.

           Job Job()
           my $job = $solutionelement->Job();
           illegal = solutionelement.Job()
           illegal = solutionelement.Job()

       Create a job that implements the solution element. Add this job to the array of jobs for
       all elements of type different to SOLVER_SOLUTION_JOB and SOLVER_SOLUTION_POOLJOB. For the
       latter two, a SOLVER_NOOB Job is created, you should replace the old job with the new one.

           const char *str()
           my $str = $solutionelement->str();
           str = solutionelement.str()
           str = solutionelement.str()

       A string describing the change the solution element consists of.

THE TRANSACTION CLASS

       Transactions describe the output of a solver run. A transaction contains a number of
       transaction elements, each either the installation of a new package or the removal of an
       already installed package. The Transaction class supports a classify() method that puts
       the elements into different groups so that a transaction can be presented to the user in a
       meaningful way.

   CONSTANTS
       Transaction element types, both active and passive

       SOLVER_TRANSACTION_IGNORE
           This element does nothing. Used to map element types that do not match the view mode.

       SOLVER_TRANSACTION_INSTALL
           This element installs a package.

       SOLVER_TRANSACTION_ERASE
           This element erases a package.

       SOLVER_TRANSACTION_MULTIINSTALL
           This element installs a package with a different version keeping the other versions
           installed.

       SOLVER_TRANSACTION_MULTIREINSTALL
           This element reinstalls an installed package keeping the other versions installed.

       Transaction element types, active view

       SOLVER_TRANSACTION_REINSTALL
           This element re-installs a package, i.e. installs the same package again.

       SOLVER_TRANSACTION_CHANGE
           This element installs a package with same name, version, architecture but different
           content.

       SOLVER_TRANSACTION_UPGRADE
           This element installs a newer version of an installed package.

       SOLVER_TRANSACTION_DOWNGRADE
           This element installs an older version of an installed package.

       SOLVER_TRANSACTION_OBSOLETES
           This element installs a package that obsoletes an installed package.

       Transaction element types, passive view

       SOLVER_TRANSACTION_REINSTALLED
           This element re-installs a package, i.e. installs the same package again.

       SOLVER_TRANSACTION_CHANGED
           This element replaces an installed package with one of the same name, version,
           architecture but different content.

       SOLVER_TRANSACTION_UPGRADED
           This element replaces an installed package with a new version.

       SOLVER_TRANSACTION_DOWNGRADED
           This element replaces an installed package with an old version.

       SOLVER_TRANSACTION_OBSOLETED
           This element replaces an installed package with a package that obsoletes it.

       Pseudo element types for showing extra information used by classify()

       SOLVER_TRANSACTION_ARCHCHANGE
           This element replaces an installed package with a package of a different architecture.

       SOLVER_TRANSACTION_VENDORCHANGE
           This element replaces an installed package with a package of a different vendor.

       Transaction mode flags

       SOLVER_TRANSACTION_SHOW_ACTIVE
           Filter for active view types. The default is to return passive view type, i.e. to show
           how the installed packages get changed.

       SOLVER_TRANSACTION_SHOW_OBSOLETES
           Do not map the obsolete view type into INSTALL/ERASE elements.

       SOLVER_TRANSACTION_SHOW_ALL
           If multiple packages replace an installed package, only the best of them is kept as
           OBSOLETE element, the other ones are mapped to INSTALL/ERASE elements. This is because
           most applications want to show just one package replacing the installed one. The
           SOLVER_TRANSACTION_SHOW_ALL makes the library keep all OBSOLETE elements.

       SOLVER_TRANSACTION_SHOW_MULTIINSTALL
           The library maps MULTIINSTALL elements to simple INSTALL elements. This flag can be
           used to disable the mapping.

       SOLVER_TRANSACTION_CHANGE_IS_REINSTALL
           Use this flag if you want to map CHANGE elements to the REINSTALL type.

       SOLVER_TRANSACTION_OBSOLETE_IS_UPGRADE
           Use this flag if you want to map OBSOLETE elements to the UPGRADE type.

       SOLVER_TRANSACTION_MERGE_ARCHCHANGES
           Do not add extra categories for every architecture change, instead cumulate them in
           one category.

       SOLVER_TRANSACTION_MERGE_VENDORCHANGES
           Do not add extra categories for every vendor change, instead cumulate them in one
           category.

       SOLVER_TRANSACTION_RPM_ONLY
           Special view mode that just returns IGNORE, ERASE, INSTALL, MULTIINSTALL elements.
           Useful if you want to find out what to feed to the underlying package manager.

       Transaction order flags

       SOLVER_TRANSACTION_KEEP_ORDERDATA
           Do not throw away the dependency graph used for ordering the transaction. This flag is
           needed if you want to do manual ordering.

   ATTRIBUTES
           Pool *pool;                             /* read only */
           $trans->{pool}
           trans.pool
           trans.pool

       Back pointer to pool.

   METHODS
           bool isempty()
           $trans->isempty()
           trans.isempty()
           trans.isempty?

       Returns true if the transaction does not do anything, i.e. has no elements.

           Solvable *newsolvables()
           my @newsolvables = $trans->newsolvables();
           newsolvables = trans.newsolvables()
           newsolvables = trans.newsolvables()

       Return all packages that are to be installed by the transaction. These are the packages
       that need to be downloaded from the repositories.

           Solvable *keptsolvables()
           my @keptsolvables = $trans->keptsolvables();
           keptsolvables = trans.keptsolvables()
           keptsolvables = trans.keptsolvables()

       Return all installed packages that the transaction will keep installed.

           Solvable *steps()
           my @steps = $trans->steps();
           steps = trans.steps()
           steps = trans.steps()

       Return all solvables that need to be installed (if the returned solvable is not already
       installed) or erased (if the returned solvable is installed). A step is also called a
       transaction element.

           int steptype(Solvable *solvable, int mode)
           my $type = $trans->steptype($solvable, $mode);
           type = trans.steptype(solvable, mode)
           type = trans.steptype(solvable, mode)

       Return the transaction type of the specified solvable. See the CONSTANTS sections for the
       mode argument flags and the list of returned types.

           TransactionClass *classify(int mode = 0)
           my @classes = $trans->classify();
           classes = trans.classify()
           classes = trans.classify()

       Group the transaction elements into classes so that they can be displayed in a structured
       way. You can use various mapping mode flags to tweak the result to match your preferences,
       see the mode argument flag in the CONSTANTS section. See the TransactionClass class for
       how to deal with the returned objects.

           Solvable othersolvable(Solvable *solvable)
           my $other = $trans->othersolvable($solvable);
           other = trans.othersolvable(solvable)
           other = trans.othersolvable(solvable)

       Return the “other” solvable for a given solvable. For installed packages the other
       solvable is the best package with the same name that replaces the installed package, or
       the best package of the obsoleting packages if the package does not get replaced by one
       with the same name.

       For to be installed packages, the “other” solvable is the best installed package with the
       same name that will be replaced, or the best packages of all the packages that are
       obsoleted if the new package does not replace a package with the same name.

       Thus, the “other” solvable is normally the package that is also shown for a given package.

           Solvable *allothersolvables(Solvable *solvable)
           my @others = $trans->allothersolvables($solvable);
           others = trans.allothersolvables(solvable)
           others = trans.allothersolvables(solvable)

       For installed packages, returns all of the packages that replace us. For to be installed
       packages, returns all of the packages that the new package replaces. The special “other”
       solvable is always the first entry of the returned array.

           long long calc_installsizechange()
           my $change = $trans->calc_installsizechange();
           change = trans.calc_installsizechange()
           change = trans.calc_installsizechange()

       Return the size change of the installed system in kilobytes (kibibytes).

           void order(int flags = 0)
           $trans->order();
           trans.order()
           trans.order()

       Order the steps in the transactions so that dependent packages are updated before packages
       that depend on them. For rpm, you can also use rpmlib’s ordering functionality, debian’s
       dpkg does not provide a way to order a transaction.

   ACTIVE/PASSIVE VIEW
       Active view lists what new packages get installed, while passive view shows what happens
       to the installed packages. Most often there’s not much difference between the two modes,
       but things get interesting if multiple packages get replaced by one new package. Say you
       have installed packages A-1-1 and B-1-1, and now install A-2-1 which has a new dependency
       that obsoletes B. The transaction elements will be

           updated   A-1-1 (other: A-2-1)
           obsoleted B-1-1 (other: A-2-1)

       in passive mode, but

           update A-2-1 (other: A-1-1)
           erase  B

       in active mode. If the mode contains SOLVER_TRANSACTION_SHOW_ALL, the passive mode list
       will be unchanged but the active mode list will just contain A-2-1.

THE TRANSACTIONCLASS CLASS

       Objects of this type are returned by the classify() Transaction method.

   ATTRIBUTES
           Transaction *transaction;               /* read only */
           $class->{transaction}
           class.transaction
           class.transaction

       Back pointer to transaction object.

           int type;                               /* read only */
           $class->{type}
           class.type
           class.type

       The type of the transaction elements in the class.

           int count;                              /* read only */
           $class->{count}
           class.count
           class.count

       The number of elements in the class.

           const char *fromstr;
           $class->{fromstr}
           class.fromstr
           class.fromstr

       The old vendor or architecture.

           const char *tostr;
           $class->{tostr}
           class.tostr
           class.tostr

       The new vendor or architecture.

           Id fromid;
           $class->{fromid}
           class.fromid
           class.fromid

       The id of the old vendor or architecture.

           Id toid;
           $class->{toid}
           class.toid
           class.toid

       The id of the new vendor or architecture.

   METHODS
           void solvables();
           my @solvables = $class->solvables();
           solvables = class.solvables()
           solvables = class.solvables()

       Return the solvables for all transaction elements in the class.

CHECKSUMS

       Checksums (also called hashes) are used to make sure that downloaded data is not corrupt
       and also as a fingerprint mechanism to check if data has changed.

   CLASS METHODS
           Chksum Chksum(Id type)
           my $chksum = solv::Chksum->new($type);
           chksum = solv.Chksum(type)
           chksum = Solv::Chksum.new(type)

       Create a checksum object. Currently the following types are supported:

           REPOKEY_TYPE_MD5
           REPOKEY_TYPE_SHA1
           REPOKEY_TYPE_SHA256

       These keys are constants in the solv class.

           Chksum Chksum(Id type, const char *hex)
           my $chksum = solv::Chksum->new($type, $hex);
           chksum = solv.Chksum(type, hex)
           chksum = Solv::Chksum.new(type, hex)

       Create an already finalized checksum object from a hex string.

           Chksum Chksum_from_bin(Id type, char *bin)
           my $chksum = solv::Chksum->from_bin($type, $bin);
           chksum = solv.Chksum.from_bin(type, bin)
           chksum = Solv::Chksum.from_bin(type, bin)

       Create an already finalized checksum object from a binary checksum.

   ATTRIBUTES
           Id type;                        /* read only */
           $chksum->{type}
           chksum.type
           chksum.type

       Return the type of the checksum object.

   METHODS
           void add(const char *str)
           $chksum->add($str);
           chksum.add(str)
           chksum.add(str)

       Add a (binary) string to the checksum.

           void add_fp(FILE *fp)
           $chksum->add_fp($file);
           chksum.add_fp(file)
           chksum.add_fp(file)

       Add the contents of a file to the checksum.

           void add_stat(const char *filename)
           $chksum->add_stat($filename);
           chksum.add_stat(filename)
           chksum.add_stat(filename)

       Stat the file and add the dev/ino/size/mtime member to the checksum. If the stat fails,
       the members are zeroed.

           void add_fstat(int fd)
           $chksum->add_fstat($fd);
           chksum.add_fstat(fd)
           chksum.add_fstat(fd)

       Same as add_stat, but instead of the filename a file descriptor is used.

           unsigned char *raw()
           my $raw = $chksum->raw();
           raw = chksum.raw()
           raw = chksum.raw()

       Finalize the checksum and return the result as raw bytes. This means that the result can
       contain NUL bytes or unprintable characters.

           const char *hex()
           my $raw = $chksum->hex();
           raw = chksum.hex()
           raw = chksum.hex()

       Finalize the checksum and return the result as hex string.

           const char *typestr()
           my $typestr = $chksum->typestr();
           typestr = chksum.typestr
           typestr = chksum.typestr

       Return the type of the checksum as a string, e.g. "sha256".

           <equality>
           if ($chksum1 == $chksum2)
           if chksum1 == chksum2:
           if chksum1 == chksum2

       Checksums are equal if they are of the same type and the finalized results are the same.

           <stringification>
           my $str = $chksum->str;
           str = str(chksum)
           str = chksum.to_s

       If the checksum is finished, the checksum is returned as "<type>:<hex>" string. Otherwise
       "<type>:unfinished" is returned.

FILE MANAGEMENT

       This functions were added because libsolv uses standard FILE pointers to read/write files,
       but languages like perl have their own implementation of files. The libsolv functions also
       support decompression and compression, the algorithm is selected by looking at the file
       name extension.

           FILE *xfopen(char *fn, char *mode = "r")
           my $file = solv::xfopen($path);
           file = solv.xfopen(path)
           file = Solv::xfopen(path)

       Open a file at the specified path. The mode argument is passed on to the stdio library.

           FILE *xfopen_fd(char *fn, int fileno)
           my $file = solv::xfopen_fd($path, $fileno);
           file = solv.xfopen_fd(path, fileno)
           file = Solv::xfopen_fd(path, fileno)

       Create a file handle from the specified file descriptor. The path argument is only used to
       select the correct (de-)compression algorithm, use an empty path if you want to make sure
       to read/write raw data. The file descriptor is dup()ed before the file handle is created.

   METHODS
           int fileno()
           my $fileno = $file->fileno();
           fileno = file.fileno()
           fileno = file.fileno()

       Return file file descriptor of the file. If the file is not open, -1 is returned.

           void cloexec(bool state)
           $file->cloexec($state);
           file.cloexec(state)
           file.cloexec(state)

       Set the close-on-exec flag of the file descriptor. The xfopen function returns files with
       close-on-exec turned on, so if you want to pass a file to some other process you need to
       call cloexec(0) before calling exec.

           int dup()
           my $fileno = $file->dup();
           fileno = file.dup()
           fileno = file.dup()

       Return a copy of the descriptor of the file. If the file is not open, -1 is returned.

           bool flush()
           $file->flush();
           file.flush()
           file.flush()

       Flush the file. Returns false if there was an error. Flushing a closed file always returns
       true.

           bool close()
           $file->close();
           file.close()
           file.close()

       Close the file. This is needed for languages like Ruby that do not destruct objects right
       after they are no longer referenced. In that case, it is good style to close open files so
       that the file descriptors are freed right away. Returns false if there was an error.

THE REPODATA CLASS

       The Repodata stores attributes for packages and the repository itself, each repository can
       have multiple repodata areas. You normally only need to directly access them if you
       implement lazy downloading of repository data. Repodata areas are created by calling the
       repository’s add_repodata() method or by using repo_add methods without the
       REPO_REUSE_REPODATA or REPO_USE_LOADING flag.

   ATTRIBUTES
           Repo *repo;                     /* read only */
           $data->{repo}
           data.repo
           data.repo

       Back pointer to repository object.

           Id id;                                  /* read only */
           $data->{id}
           data.id
           data.id

       The id of the repodata area. Repodata ids of different repositories overlap.

   METHODS
           internalize()
           $data->internalize();
           data.internalize()
           data.internalize()

       Internalize newly added data. The lookup functions will only see the new data after it has
       been internalized.

           bool write(FILE *fp)
           $data->write($fp);
           data.write(fp)
           data.write(fp)

       Write the contents of the repodata area as solv file.

           Id str2dir(const char *dir, bool create = 1)
           my $did = data->str2dir($dir);
           did = data.str2dir(dir)
           did = data.str2dir(dir)

           const char *dir2str(Id did, const char *suffix = 0)
           $dir = pool->dir2str($did);
           dir = pool.dir2str(did)
           dir = pool.dir2str(did)

       Convert a string (directory) into an Id and back. If the string is currently not in the
       pool and create is false, zero is returned.

           void add_dirstr(Id solvid, Id keyname, Id dir, const char *str)
           $data->add_dirstr($solvid, $keyname, $dir, $string);
           data.add_dirstr(solvid, keyname, dir, string)
           data.add_dirstr(solvid, keyname, dir, string)

       Add a file path consisting of a dirname Id and a basename string.

           bool add_solv(FILE *fp, int flags = 0)
           $data->add_solv($fp);
           data.add_solv(fp)
           data.add_solv(fp)

       Replace a stub repodata object with the data from a solv file. This method automatically
       adds the REPO_USE_LOADING flag. It should only be used from a load callback.

           void create_stubs()
           $data->create_stubs();
           data.create_stubs()
           data.create_stubs()

       Create stub repodatas from the information stored in the repodata meta area.

           void extend_to_repo()
           $data->extend_to_repo();
           data.extend_to_repo()
           data.extend_to_repo()

       Extend the repodata so that it has the same size as the repo it belongs to. This method is
       needed when setting up a new extension repodata so that it matches the repository size. It
       is also needed when switching to a just written repodata extension to make the repodata
       match the written extension (which is always of the size of the repo).

           <equality>
           if ($data1 == $data2)
           if data1 == data2:
           if data1 == data2

       Two repodata objects are equal if they belong to the same repository and have the same id.

   DATA RETRIEVAL METHODS
           const char *lookup_str(Id solvid, Id keyname)
           my $string = $data->lookup_str($solvid, $keyname);
           string = data.lookup_str(solvid, keyname)
           string = data.lookup_str(solvid, keyname)

           const char *lookup_id(Id solvid, Id keyname)
           my $string = $data->lookup_id($solvid, $keyname);
           string = data.lookup_id(solvid, keyname)
           string = data.lookup_id(solvid, keyname)

           unsigned long long lookup_num(Id solvid, Id keyname, unsigned long long notfound = 0)
           my $num = $data->lookup_num($solvid, $keyname);
           num = data.lookup_num(solvid, keyname)
           num = data.lookup_num(solvid, keyname)

           bool lookup_void(Id solvid, Id keyname)
           my $bool = $data->lookup_void($solvid, $keyname);
           bool = data.lookup_void(solvid, keyname)
           bool = data.lookup_void(solvid, keyname)

           Id *lookup_idarray(Id solvid, Id keyname)
           my @ids = $data->lookup_idarray($solvid, $keyname);
           ids = data.lookup_idarray(solvid, keyname)
           ids = data.lookup_idarray(solvid, keyname)

           Chksum lookup_checksum(Id solvid, Id keyname)
           my $chksum = $data->lookup_checksum($solvid, $keyname);
           chksum = data.lookup_checksum(solvid, keyname)
           chksum = data.lookup_checksum(solvid, keyname)

       Lookup functions. Return the data element stored in the specified solvable. The methods
       probably only make sense to retrieve data from the special SOLVID_META solvid that stores
       repodata meta information.

   DATA STORAGE METHODS
           void set_str(Id solvid, Id keyname, const char *str)
           $data->set_str($solvid, $keyname, $str);
           data.set_str(solvid, keyname, str)
           data.set_str(solvid, keyname, str)

           void set_id(Id solvid, Id keyname, DepId id)
           $data->set_id($solvid, $keyname, $id);
           data.set_id(solvid, keyname, id)
           data.set_id(solvid, keyname, id)

           void set_num(Id solvid, Id keyname, unsigned long long num)
           $data->set_num($solvid, $keyname, $num);
           data.set_num(solvid, keyname, num)
           data.set_num(solvid, keyname, num)

           void set_void(Id solvid, Id keyname)
           $data->set_void($solvid, $keyname);
           data.set_void(solvid, keyname)
           data.set_void(solvid, keyname)

           void set_poolstr(Id solvid, Id keyname, const char *str)
           $data->set_poolstr($solvid, $keyname, $str);
           data.set_poolstr(solvid, keyname, str)
           data.set_poolstr(solvid, keyname, str)

           void set_checksum(Id solvid, Id keyname, Chksum *chksum)
           $data->set_checksum($solvid, $keyname, $chksum);
           data.set_checksum(solvid, keyname, chksum)
           data.set_checksum(solvid, keyname, chksum)

           void set_sourcepkg(Id solvid, const char *sourcepkg)
           $data.set_sourcepkg($solvid, $sourcepkg);
           data.set_sourcepkg(solvid, sourcepkg)
           data.set_sourcepkg(solvid, sourcepkg)

           void set_location(Id solvid, unsigned int mediano, const char *location)
           $data.set_location($solvid, $mediano, $location);
           data.set_location(solvid, mediano, location)
           data.set_location(solvid, mediano, location)

           void add_idarray(Id solvid, Id keyname, DepId id)
           $data->add_idarray($solvid, $keyname, $id);
           data.add_idarray(solvid, keyname, id)
           data.add_idarray(solvid, keyname, id)

           Id new_handle()
           my $handle = $data->new_handle();
           handle = data.new_handle()
           handle = data.new_handle()

           void add_flexarray(Id solvid, Id keyname, Id handle)
           $data->add_flexarray($solvid, $keyname, $handle);
           data.add_flexarray(solvid, keyname, handle)
           data.add_flexarray(solvid, keyname, handle)

           void unset(Id solvid, Id keyname)
           $data->unset($solvid, $keyname);
           data.unset(solvid, keyname)
           data.unset(solvid, keyname)

       Data storage methods. Probably only useful to store data in the special SOLVID_META solvid
       that stores repodata meta information. Note that repodata areas can have their own Id pool
       (see the REPO_LOCALPOOL flag), so be careful if you need to store ids. Arrays are created
       by calling the add function for every element. A flexarray is an array of sub-structures,
       call new_handle to create a new structure, use the handle as solvid to fill the structure
       with data and call add_flexarray to put the structure in an array.

THE DATAPOS CLASS

       Datapos objects describe a specific position in the repository data area. Thus they are
       only valid until the repository is modified in some way. Datapos objects can be created by
       the pos() and parentpos() methods of a Datamatch object or by accessing the “meta”
       attribute of a repository.

   ATTRIBUTES
           Repo *repo;                     /* read only */
           $data->{repo}
           data.repo
           data.repo

       Back pointer to repository object.

   METHODS
           Dataiterator(Id keyname, const char *match, int flags)
           my $di = $datapos->Dataiterator($keyname, $match, $flags);
           di = datapos.Dataiterator(keyname, match, flags)
           di = datapos.Dataiterator(keyname, match, flags)

       Create a Dataiterator at the position of the datapos object.

           const char *lookup_deltalocation(unsigned int *OUTPUT)
           my ($location, $mediano) = $datapos->lookup_deltalocation();
           location, mediano = datapos.lookup_deltalocation()
           location, mediano = datapos.lookup_deltalocation()

       Return a tuple containing the on-media location and an optional media number for a delta
       rpm. This obviously only works if the data position points to structure describing a delta
       rpm.

           const char *lookup_deltaseq()
           my $seq = $datapos->lookup_deltaseq();
           seq = datapos.lookup_deltaseq();
           seq = datapos.lookup_deltaseq();

       Return the delta rpm sequence from the structure describing a delta rpm.

   DATA RETRIEVAL METHODS
           const char *lookup_str(Id keyname)
           my $string = $datapos->lookup_str($keyname);
           string = datapos.lookup_str(keyname)
           string = datapos.lookup_str(keyname)

           Id lookup_id(Id solvid, Id keyname)
           my $id = $datapos->lookup_id($keyname);
           id = datapos.lookup_id(keyname)
           id = datapos.lookup_id(keyname)

           unsigned long long lookup_num(Id keyname, unsigned long long notfound = 0)
           my $num = $datapos->lookup_num($keyname);
           num = datapos.lookup_num(keyname)
           num = datapos.lookup_num(keyname)

           bool lookup_void(Id keyname)
           my $bool = $datapos->lookup_void($keyname);
           bool = datapos.lookup_void(keyname)
           bool = datapos.lookup_void(keyname)

           Id *lookup_idarray(Id keyname)
           my @ids = $datapos->lookup_idarray($keyname);
           ids = datapos.lookup_idarray(keyname)
           ids = datapos.lookup_idarray(keyname)

           Chksum lookup_checksum(Id keyname)
           my $chksum = $datapos->lookup_checksum($keyname);
           chksum = datapos.lookup_checksum(keyname)
           chksum = datapos.lookup_checksum(keyname)

       Lookup functions. Note that the returned Ids are always translated into the Ids of the
       global pool even if the repodata area contains its own pool.

           Dataiterator Dataiterator(Id keyname, const char *match = 0, int flags = 0)
           my $di = $datapos->Dataiterator($keyname, $match, $flags);
           di = datapos.Dataiterator(keyname, match, flags)
           di = datapos.Dataiterator(keyname, match, flags)

           for my $d (@$di)
           for d in di:
           for d in di

       Iterate over the matching data elements. See the Dataiterator class for more information.

THE ALTERNATIVE CLASS

       An Alternative object describes a branch point in the solving process. The solver found
       more than one good way to fulfill a dependency and chose one. It recorded the other
       possibilities in the alternative object so that they can be presented to the user in the
       case a different solution is preferable.

   ATTRIBUTES
           Solver *solv;                   /* read only */
           $alternative->{solv}
           alternative.solv
           alternative.solv

       Back pointer to solver object.

           Id type;                        /* read only */
           $alternative->{type}
           alternative.type
           alternative.type

       The type of the alternative. Alternatives can be created because of rule fulfillment,
       because of recommended packages, and because of suggested packages (currently unused). See
       below for a list of valid types.

           Rule rule;                      /* read only */
           $alternative->{rule}
           alternative.rule
           alternative.rule

       The rule that caused the creation of the alternative (SOLVER_ALTERNATIVE_TYPE_RULE).

           Dep *dep;                       /* read only */
           $ruleinfo->{dep}
           ruleinfo.dep
           ruleinfo.dep

       The dependency that caused the creation of the alternative
       (SOLVER_ALTERNATIVE_TYPE_RECOMMENDS).

           Dep *depsolvable;               /* read only */
           $ruleinfo->{depsolvable}
           ruleinfo.depsolvable
           ruleinfo.depsolvable

       The package containing the dependency (SOLVER_ALTERNATIVE_TYPE_RECOMMENDS).

           Solvable chosen;                /* read only */
           $alternative->{chosen}
           alternative.chosen
           alternative.chosen

       The solvable that the solver chose from the alternative’s package set.

   CONSTANTS
       SOLVER_ALTERNATIVE_TYPE_RULE
           The alternative was created when fulfilling a rule.

       SOLVER_ALTERNATIVE_TYPE_RECOMMENDS
           The alternative was created when fulfilling a recommends dependency.

       SOLVER_ALTERNATIVE_TYPE_SUGGESTS
           The alternative was created when fulfilling a suggests dependency.

   METHODS
           Solvable *choices()
           my @choices = $alternative->choices();
           choices = alternative.choices
           choices = alternative.choices

       Return the set of solvables that the solver could choose from when creating the
       alternative.

           <stringification>
           my $str = $alternative->str;
           str = str(alternative)
           str = alternative.to_s

       Return a string describing the alternative.

THE DECISION CLASS

       A decision is created when the solver fulfills dependencies. It can be either to install a
       package to satisfy a dependency or to conflict a dependency because it conflicts with
       another package or its dependencies cannot be met. Most decisions are caused by rule
       processing, but there are some other types like orphaned package handling or weak
       dependency handling.

   ATTRIBUTES
           Solver *solv;                   /* read only */
           $decision->{solv}
           decision.solv
           decision.solv

       Back pointer to solver object.

           Id p;                           /* read only */
           $decision->{p}
           decision.p
           decision.p

       The decision package id, positive for installs and negative for conflicts.

           int reason;                     /* read only */
           $decision->{reason}
           decision.reason
           decision.reason

       The reason for the decision. See the SOLVER_REASON_ constants.

           int infoid;                     /* read only */
           $decision->{infoid}
           decision.infoid
           decision.infoid

       Extra info for the decision. This is the rule id for decisions caused by rule fulfillment.

           Solvable solvable;              /* read only */
           $decision->{solvable}
           decision.solvable
           decision.solvable

       The decision package object.

           Rule rule()                     /* read only */
           $decision->{rule}
           decision.rule
           decision.rule

       The rule object for decisions that where caused by rule fulfilment.

   METHODS
           Ruleinfo info()
           my $info = $decision->info();
           info = decision.info()
           info = decision.info()

       Return a Ruleinfo object describing the decision. Some reasons like SOLVER_REASON_WEAKDEP
       are not caused by rules, but can be expressed by a Ruleinfo object.

           Ruleinfo *allinfos()
           my @infos = $decision->allinfos();
           infos = decision.allinfos()
           infos = decision.allinfos()

       Same as info(), but all Ruleinfo objects describing the decision are returned.

           const char *reasonstr()
           my str = $decision->reasonstr()
           str = decision.reasonstr()
           str = decision.reasonstr()

       Return a string describing why a decision was done (but without the decision itself).

           <stringification>
           my $str = $decison->str;
           str = str(decision)
           str = decision.to_s

       Return a string describing the decision (but without the reason).

THE DECISIONSET CLASS

       A decisionset consists of multiple decisions of the same reason and type that can be
       presented to the user as a single action.

   ATTRIBUTES
           Solver *solv;                   /* read only */
           $decision->{solv}
           decision.solv
           decision.solv

       Back pointer to solver object.

           Id p;                           /* read only */
           $decision->{p}
           decision.p
           decision.p

       The package id of the first decision, positive for installs and negative for conflicts.

           int reason;                     /* read only */
           $decision->{reason}
           decision.reason
           decision.reason

       The reason for the decisions in the set. See the SOLVER_REASON_ constants.

           int type;                       /* read only */
           $ruleinfo->{type}
           ruleinfo.type
           ruleinfo.type

       The type of the decision info. See the constant section of the solver class for the rule
       type list and the special type list.

           Dep *dep;                       /* read only */
           $ruleinfo->{dep}
           ruleinfo.dep
           ruleinfo.dep

       The dependency that caused the decision

           Dep *dep_id;                    /* read only */
           $ruleinfo->{dep_id}
           ruleinfo.dep_id
           ruleinfo.dep_id

       The Id of the dependency that caused the decision.

   METHODS
           Decision *decisions()
           my @decisions = $decisionset->decisions();
           decisions = decisionset.decisions()
           decisions = decisionset.decisions()

       Return all the decisions of the set.

           Solvable *solvables()
           my @pkgs = $decisionset->solvables();
           pkgs = decisionset.solvables()
           pkgs = decisionset.solvables()

       Return all the packages that were decided in the set.

           const char *reasonstr()
           my str = $decision->reasonstr();
           str = decision.reasonstr()
           str = decision.reasonstr()

       Return a string describing why the decisions were done (but without the decisions
       themself).

           <stringification>
           my $str = $decison->str;
           str = str(decision)
           str = decision.to_s

       Return a string describing the decisions (but without the reason).

AUTHOR

       Michael Schroeder <mls@suse.de>