Provided by: libsolv-doc_0.7.28-1build2_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.

       POOL_FLAG_NOWHATPROVIDESAUX
           Disable the creation of the auxiliary whatprovides index. This saves a bit of memory but also makes
           the whatprovides lookups a bit slower.

       POOL_FLAG_WHATPROVIDESWITHDISABLED
           Make the whatprovides index also contain disabled packages. This means that you do not need to
           recreate the index if a package is enabled/disabled, i.e. the pool→considered bitmap is changed.

   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
       storing 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 breaking 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 proving 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 proving 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_SHA224
           REPOKEY_TYPE_SHA256
           REPOKEY_TYPE_SHA384
           REPOKEY_TYPE_SHA512

       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>