Provided by: latexml_0.7.0-1_all bug

NAME

       "LaTeXML::Package" - Support for package implementations and document customization.

SYNOPSIS

       This package defines and exports most of the procedures users will need to customize or extend LaTeXML.
       The LaTeXML implementation of some package might look something like the following, but see the installed
       "LaTeXML/Package" directory for realistic examples.

         use LaTeXML::Package;
         use strict;
         #
         # Load "anotherpackage"
         RequirePackage('anotherpackage');
         #
         # A simple macro, just like in TeX
         DefMacro('\thesection', '\thechapter.\roman{section}');
         #
         # A constructor defines how a control sequence generates XML:
         DefConstructor('\thanks{}', "<ltx:thanks>#1</ltx:thanks>");
         #
         # And a simple environment ...
         DefEnvironment('{abstract}','<abstract>#body</abstract>');
         #
         # A math  symbol \Real to stand for the Reals:
         DefMath('\Real', "\x{211D}", role=>'ID');
         #
         # Or a semantic floor:
         DefMath('\floor{}','\left\lfloor#1\right\rfloor');
         #
         # More esoteric ...
         # Use a RelaxNG schema
         RelaxNGSchema("MySchema");
         # Or use a special DocType if you have to:
         # DocType("rootelement",
         #         "-//Your Site//Your DocType",'your.dtd',
         #          prefix=>"http://whatever/");
         #
         # Allow sometag elements to be automatically closed if needed
         Tag('prefix:sometag', autoClose=>1);
         #
         # Don't forget this, so perl knows the package loaded.
         1;

DESCRIPTION

       To provide a LaTeXML-specific version of a LaTeX package "mypackage.sty" or class "myclass.cls" (so that
       eg. "\usepackage{mypackage}" works), you create the file "mypackage.sty.ltxml" or "myclass.cls.ltxml" and
       save it in the searchpath (current directory, or one of the directories given to the --path option, or
       possibly added to the variable SEARCHPATHS).  Similarly, to provide document-specific customization for,
       say, "mydoc.tex", you would create the file "mydoc.latexml" (typically in the same directory).  However,
       in the first cases, "mypackage.sty.ltxml" are loaded instead of "mypackage.sty", while a file like
       "mydoc.latexml" is loaded in addition to "mydoc.tex".  In either case, you'll "use LaTeXML::Package;" to
       import the various declarations and defining forms that allow you to specify what should be done with
       various control sequences, whether there is special treatment of certain document elements, and so forth.
       Using "LaTeXML::Package" also imports the functions and variables defined in LaTeXML::Global, so see that
       documentation as well.

       Since LaTeXML attempts to mimic TeX, a familiarity with TeX's processing model is also helpful.
       Additionally, it is often useful, when implementing non-trivial behaviour, to think TeX-like.

       Many of the following forms take code references as arguments or options.  That is, either a reference to
       a defined sub, "\&somesub", or an anonymous function sub { ... }.  To document these cases, and the
       arguments that are passed in each case, we'll use a notation like CODE($token,..).

   Control Sequences
       Many of the following forms define the behaviour of control sequences.  In TeX you'll typically only
       define macros. In LaTeXML, we're effectively redefining TeX itself,  so we define macros as well as
       primitives, registers, constructors and environments.  These define the behaviour of these commands when
       processed during the various phases of LaTeX's immitation of TeX's digestive tract.

       The first argument to each of these defining forms ("DefMacro", "DefPrimive", etc) is a prototype
       consisting of the control sequence being defined along with the specification of parameters required by
       the control sequence.  Each parameter describes how to parse tokens following the control sequence into
       arguments or how to delimit them.  To simplify coding and capture common idioms in TeX/LaTeX programming,
       latexml's parameter specifications are more expressive than TeX's  "\def" or LaTeX's "\newcommand".
       Examples of the prototypes for familiar TeX or LaTeX control sequences are:

          DefConstructor('\usepackage[]{}',...
          DefPrimitive('\multiply Variable SkipKeyword:by Number',..
          DefPrimitive('\newcommand OptionalMatch:* {Token}[][]{}', ...

       Control Sequence Parameters

       The general syntax for parameter for a control sequence is something like

         OpenDelim? Modifier? Type (: value (| value)* )? CloseDelim?

       The enclosing delimiters, if any, are either {} or [], affect the way the argument is delimited.  With
       {}, a regular TeX argument (token or sequence balanced by braces) is read before parsing according to the
       type (if needed).  With [], a LaTeX optional argument is read, delimited by (non-nested) square brackets.

       The modifier can be either "Optional" or "Skip", allowing the argument to be optional. For "Skip", no
       argument is contributed to the argument list.

       The shorthands {} and [] default the type to "Plain" and reads a normal TeX argument or LaTeX default
       argument.

       The predefined argument types are as follows.

       "Plain", "Semiverbatim"
           Reads a standard TeX argument being either the next token, or if the next token is an {, the balanced
           token  list.   In  the  case of "Semiverbatim", many catcodes are disabled, which is handy for URL's,
           labels and similar.

       "Token", "XToken"
           Read a single TeX Token.  For "XToken", if the next token is expandable, it  is  repeatedly  expanded
           until an unexpandable token remains, which is returned.

       "Number", "Dimension", "Glue" or "MuGlue"
           Read  an  Object  corresponding  to  Number, Dimension, Glue or MuGlue, using TeX's rules for parsing
           these objects.

       "Until:"match
           Reads tokens until a match to the tokens match is found, returning the tokens  preceding  the  match.
           This corresponds to TeX delimited arguments.

       "UntilBrace"
           Reads  tokens  until  the  next  open  brace  "{".   This  corresponds  to the peculiar TeX construct
           "\def\foo#{...".

       "Match:"match(|match)*, "Keyword:"match(|match)*
           Reads tokens expecting a match to one of the token lists match, returning the one  that  matches,  or
           undef.  For "Keyword", case and catcode of the matches are ignored.  Additionally, any leading spaces
           are skipped.

       "Balanced"
           Read tokens until a closing }, but respecting nested {} pairs.

       "Variable"
           Reads a token, expanding if necessary, and expects a control sequence naming a writable register.  If
           such is found, it returns an array of the corresponding definition object, and any arguments required
           by that definition.

       "SkipSpaces"
           Skips any space tokens, but contributes nothing to the argument list.

       Control of Scoping

       Most  defining  commands accept an option to control how the definition is stored, "scope=>$scope", where
       $scope can be c<'global'> for global definitions, 'local', to be stored in the current stack frame, or  a
       string  naming  a  scope.  A scope saves a set of definitions and values that can be activated at a later
       time.

       Particularly interesting forms of scope are those  that  get  automatically  activated  upon  changes  of
       counter and label.  For example, definitions that have "scope=>'section:1.1'"  will be activated when the
       section number is "1.1", and will be deactivated when the section ends.

       Macros

       "DefMacro($prototype,$string | $tokens | $code,%options);"
           Defines  the  macro  expansion  for  $prototype.   If  a $string is supplied, it will be tokenized at
           definition time, and any macro arguments will be substituted for  parameter  indicators  (eg  #1)  at
           expansion  time; the result is used as the expansion of the control sequence.  The only option, other
           than "scope", is "isConditional" which should be true, for conditional control  sequences  (TeX  uses
           these to keep track of conditional nesting when skipping to \else or \fi).

           If defined by $code, the form is "CODE($gullet,@args)" and it must return a list of LaTeXML::Token's.

       "DefMacroI($cs,$paramlist,$string | $tokens | $code,%options);"
           Internal  form  of "DefMacro" where the control sequence and parameter list have already been parsed;
           useful for definitions from within code.  Also, slightly more efficient for macros with no  arguments
           (use "undef" for $paramlist).

       Primitives

       "DefPrimitive($prototype,CODE($stomach,@args),%options);"
           Define  a  primitive control sequence.  These are usually done for side effect and so CODE should end
           with "return;", but can also return a list of digested items.

           The only option is for the  special  case:  "isPrefix=>1"  is  used  for  assignment  prefixes  (like
           \global).

       "DefPrimitiveI($cs,$paramlist,CODE($stomach,@args),%options);"
           Internal  form  of  "DefPrimitive"  where  the  control sequence and parameter list have already been
           parsed; useful for definitions from within code.

       "DefRegister($prototype,$value,%options);"
           Defines a register with the given initial value (a Number, Dimension, Glue, MuGlue or  Tokens  ---  I
           haven't  handled Box's yet).  Usually, the $prototype is just the control sequence, but registers are
           also handled by prototypes like "\count{Number}". "DefRegister" arranges that the register value  can
           be accessed when a numeric, dimension, ... value is being read, and also defines the control sequence
           for assignment.

           Options are

           "readonly"
               specifies if it is not allowed to change this value.

           "getter"=>CODE(@args) =item "setter"=>CODE($value,@args)
               By  default the value is stored in the State's Value table under a name concatenating the control
               sequence and argument values.  These options allow other means of fetching and storing the value.

       "DefRegisterI($cs,$paramlist,$value,%options);"
           Internal form of "DefRegister" where the control  sequence  and  parameter  list  have  already  been
           parsed; useful for definitions from within code.

       Constructors

       "DefConstructor($prototype,$xmlpattern | $code,%options);"
           The  Constructor  is  where  LaTeXML really starts getting interesting; invoking the control sequence
           will generate an arbitrary XML fragment in the document tree.  More specifically:  during  digestion,
           the  arguments will be read and digested, creating a LaTeXML::Whatsit to represent the object. During
           absorbtion by the LaTeXML::Document, the "Whatsit" will generate the XML fragment  according  to  the
           replacement $xmlpattern, or by executing "CODE".

           The  $xmlpattern  is  simply  a  bit  of  XML as a string with certain substitutions to be made.  The
           substitutions are of the following forms:

           If code is supplied,  the form is "CODE($document,@args,%properties)"

           #1, #2 ... #name
               These are replaced by the corresponding argument (for #1) or property (for #name) stored with the
               Whatsit. Each are turned into  a  string  when  it  appears  as  in  an  attribute  position,  or
               recursively processed when it appears as content.

           "&function(@args)"
               Another  form of substituted value is prefixed with "&" which invokes a function.  For example, "
               &func(#1) " would invoke the function "func" on the first argument to the control sequence;  what
               it returns will be inserted into the document.

           "?COND(pattern)"  or "?COND(ifpattern)(elsepattern)"
               Patterns  can  be  conditionallized using this form.  The "COND" is any of the above expressions,
               considered true if the result is non-empty.  Thus "?#1(<foo/>)" would add the empty element "foo"
               if the first argument were given.

           "^" If the constuctor begins with "^", the XML fragment is allowed to float up to a parent node  that
               is allowed to contain it, according to the Document Type.

           The  Whatsit  property  "font" is defined by default.  Additional properties "body" and "trailer" are
           defined    when     "captureBody"     is     true,     or     for     environments.      By     using
           "$whatsit->setProperty(key=>$value);"  within  "afterDigest",  or  by  using the "properties" option,
           other properties can be added.

           DefConstructor options are

           mode=>(text|display_math|inline_math)
               Changes to this mode during digestion.

           bounded=>boolean
               If true, TeX grouping (ie. "{}") is enforced around this invocation.

           requireMath=>boolean
           forbidMath=>boolean
               These specify whether the given constructor can only appear, or cannot appear, in math mode.

           font=>{fontspec...}
               Specifies the font to be set by this invocation.  See "MergeFont" If the font change is  to  only
               apply to this construct, you would also use "<bounded="1>>.

           reversion=>$texstring or CODE($whatsit,#1,#2,...)
               Specifies  the  reversion of the invocation back into TeX tokens (if the default reversion is not
               appropriate).  The $textstring string can include #1,#2...  The CODE is called with the  $whatsit
               and digested arguments.

           properties=>{prop=>value,...} or CODE($stomach,#1,#2...)
               This  option  supplies  additional  properties  to be set on the generated Whatsit.  In the first
               form, the values can be of any type, but (1) if it is a code references, it takes the  same  args
               ($stomach,#1,#2,...)  and should return a value.  and (2) if the value is a string, occurances of
               #1 (etc) are replaced by the corresponding argument.  In the second form, the code should  return
               a hash of properties.

           beforeDigest=>CODE($stomach)
               This option supplies a Daemon to be executed during digestion just before the Whatsit is created.
               The CODE should either return nothing (return;) or a list of digested items (Box's,List,Whatsit).
               It can thus change the State and/or add to the digested output.

           afterDigest=>CODE($stomach,$whatsit)
               This  option supplies a Daemon to be executed during digestion just after the Whatsit is created.
               it should either return nothing (return;) or digested items.   It  can  thus  change  the  State,
               modify the Whatsit, and/or add to the digested output.

           beforeConstruct=>CODE($document,$whatsit)
               Supplies CODE to execute before constructing the XML (generated by $replacement).

           afterConstruct=>CODE($document,$whatsit)
               Supplies CODE to execute after constructing the XML.

           captureBody=>boolean or Token
               if  true,  arbitrary  following  material  will  be  accumulated  into a `body' until the current
               grouping level is reverted, or till the "Token" is encountered if the option is a "Token".   This
               body is available as the "body" property of the Whatsit.  This is used by environments and math.

           alias=>$control_sequence
               Provides a control sequence to be used when reverting Whatsit's back to Tokens, in cases where it
               isn't the command used in the $prototype.

           nargs=>$nargs
               This gives a number of args for cases where it can't be infered directly from the $prototype (eg.
               when more args are explictly read by Daemons).

           scope=>$scope
               See "scope".

       "DefConstructorI($cs,$paramlist,$xmlpattern | $code,%options);"
           Internal  form  of  "DefConstructor"  where the control sequence and parameter list have already been
           parsed; useful for definitions from within code.

       "DefMath($prototype,$tex,%options);"
           A common shorthand constructor; it defines a control sequence that  creates  a  mathematical  object,
           such  as  a  symbol,  function  or  operator  application.   The options given can effectively create
           semantic macros that contribute to the eventual parsing of mathematical content.  In  particular,  it
           generates  an  XMDual  using  the  replacement $tex for the presentation.  The content information is
           drawn from the name and options

           These "DefConstructor" options also apply:

             reversion, alias, beforeDigest, afterDigest,
             beforeConstruct, afterConstruct and scope.

           Additionally, it accepts

           style=>astyle
               adds a style attribute to the object.

           name=>aname
               gives a name attribute for the object

           omcd=>cdname
               gives the OpenMath content dictionary that name is from.

           role=>grammatical_role
               adds a grammatical role attribute to the object; this specifies the  grammatical  role  that  the
               object plays in surrounding expressions.  This direly needs documentation!

           font=>{fontspec}
               Specifies the font to be used for when creating this object.  See "MergeFont".

           scriptpos=>boolean
               Controls  whether any sub and super-scripts will be stacked over or under this object, or whether
               they will appear in the usual position.

               WRONG: Redocument this!

           operator_role=>grammatical_role
           operator_scriptpos=>boolean
               These two are similar to "role" and "scriptpos", but are used in unusual cases.  These  apply  to
               the given attributes to the operator token in the content branch.

           nogroup=>boolean
               Normally,  these  commands are digested with an implicit grouping around them, so that changes to
               fonts, etc, are local.  Providing "<noggroup="1>> inhibits this.

       "DefMathI($cs,$paramlist,$tex,%options);"
           Internal form of "DefMath" where the control sequence and parameter list have  already  been  parsed;
           useful for definitions from within code.

       "DefEnvironment($prototype,$replacement,%options);"
           Defines  an Environment that generates a specific XML fragment.  The $replacement is of the same form
           as that for DefConstructor, but will generally  include  reference  to  the  "#body"  property.  Upon
           encountering  a "\begin{env}":  the mode is switched, if needed, else a new group is opened; then the
           environment name is noted; the beforeDigest daemon is run.  Then the Whatsit representing  the  begin
           command  (but  ultimately  the  whole environment) is created and the afterDigestBegin daemon is run.
           Next, the body  will  be  digested  and  collected  until  the  balancing  "\end{env}".    Then,  any
           afterDigest  daemon  is  run,  the  environment  is  ended, finally the mode is ended or the group is
           closed.  The body and "\end{env}" whatsit are added  to  the  "\begin{env}"'s  whatsit  as  body  and
           trailer, respectively.

           It shares options with "DefConstructor":

            mode, requireMath, forbidMath, properties, nargs,
            font, beforeDigest, afterDigest, beforeConstruct,
            afterConstruct and scope.

           Additionally,  "afterDigestBegin"  is  effectively  an  "afterDigest"  for  the "\begin{env}" control
           sequence.

       "DefEnvironmentI($name,$paramlist,$replacement,%options);"
           Internal form of "DefEnvironment" where the control sequence and parameter  list  have  already  been
           parsed; useful for definitions from within code.

   Class and Packages
       "RequirePackage($package,%options);"
           Finds  and  loads a package implementation (usually "*.sty.ltxml", unless "raw" is specified) for the
           required $package.  The options are:

           "type=>type" specifies the file type (default "sty".
           "options=>[...]" specifies a list of package options.
           "raw=>1" specifies that it is allowable to try to read a raw TeX style file.
       "LoadClass($class,%options);"
           Finds and loads a class definition (usually "*.cls.ltxml").  The only option is

           "options=>[...]" specifies a list of class options.
       "FindFile($name,%options);"
           Find an appropriate file with the given $name in the current directories in "SEARCHPATHS".  If a file
           ending with ".ltxml" is found, it will be preferred.  The options are:

           "type=>type" specifies the file type (default "sty".
           "raw=>1" specifies that it is allowable to try to read a raw TeX style file.
       "DeclareOption($option,$code);"
           Declares an option for the current package or class.  The $code can be a string or Tokens (which will
           be macro expanded), or can be a code reference which is treated as a primitive.

           If a package or class wants to accomodate options, it should start with one or more "DeclareOptions",
           followed by "ProcessOptions()".

       "PassOptions($name,$ext,@options);"
           Causes the given @options (strings) to be passed to the package (if $ext is "sty") or class (if  $ext
           is "cls") named by $name.

       "ProcessOptions();"
           Processes  the  options that have been passed to the current package or class in a fashion similar to
           LaTeX.  If the keyword "inorder=>1" is given, the options are processed in the order they were  used,
           like "ProcessOptions*".

       "ExecuteOptions(@options);"
           Process the options given explicitly in @options.

   Counters and IDs
       "NewCounter($ctr,$within,%options);"
           Defines a new counter, like LaTeX's \newcounter, but extended.  It defines a counter that can be used
           to generate reference numbers, and defines \the$ctr, etc. It also defines an "uncounter" which can be
           used to generate ID's (xml:id) for unnumbered objects.  $ctr is the name of the counter.  If defined,
           $within  is the name of another counter which, when incremented, will cause this counter to be reset.
           The options are

              idprefix  Specifies a prefix to be used to generate ID's
                        when using this counter
              nested    Not sure that this is even sane.

       "$num = CounterValue($ctr);"
           Fetches the value associated with the counter $ctr.

       "$tokens = StepCounter($ctr);"
           Analog of "\stepcounter", steps the counter and returns the expansion  of  "\the$ctr".   Usually  you
           should use "RefStepCounter($ctr)" instead.

       "$keys = RefStepCounter($ctr);"
           Analog   of   "\refstepcounter",   steps   the  counter  and  returns  a  hash  containing  the  keys
           "refnum="$refnum, id=>$id>.  This makes it suitable for use in a "properties" option to constructors.
           The "id" is generated in parallel with the reference number to assist debugging.

       "$keys = RefStepID($ctr);"
           Like to "RefStepCounter", but only steps the "uncounter", and returns only the id;   This  is  useful
           for unnumbered cases of objects that normally get both a refnum and id.

       "ResetCounter($ctr);"
           Resets the counter $ctr to zero.

       "GenerateID($document,$node,$whatsit,$prefix);"
           Generates  an  ID  for  nodes during the construction phase, useful for cases where the counter based
           scheme is inappropriate.  The calling pattern makes it appropriate for use in Tag, as in
              Tag('ltx:para',sub { GenerateID(@_,'p'); })

           If $node doesn't already have an xml:id set, it computes  an  appropriate  id  by  concatenating  the
           xml:id of the closest ancestor with an id (if any), the prefix and a unique counter.

   Document Model
       Constructors define how TeX markup will generate XML fragments, but the Document Model is used to control
       exactly how those fragments are assembled.

       "Tag($tag,%properties);"
           Declares properties of elements with the name $tag.

           The recognized properties are:

           autoOpen=>boolean
               Specifies  whether  this $tag can be automatically opened if needed to insert an element that can
               only be contained by $tag.  This property can help match the more  SGML-like LaTeX to XML.

           autoClose=>boolean
               Specifies whether this $tag can be automatically closed if needed to close an ancestor  node,  or
               insert  an  element  into an ancestor.  This property can help match the more  SGML-like LaTeX to
               XML.

           afterOpen=>CODE($document,$box)
               Provides CODE to be run whenever a node with this $tag is opened.  It is called with the document
               being constructed, and the initiating digested object as arguments.  It is called after the  node
               has been created, and after any initial attributes due to the constructor (passed to openElement)
               are added.

           afterClose=>CODE($document,$box)
               Provides CODE to be run whenever a node with this $tag is closed.  It is called with the document
               being constructed, and the initiating digested object as arguments.

       "RelaxNGSchema($schemaname);"
           Specifies the schema to use for determining document model.  You can leave off the extension; it will
           look for ".rng", and maybe eventually, ".rnc" once that is implemented.

       "RegisterNamespace($prefix,$URL);"
           Declares  the  $prefix  to  be  associated  with the given $URL.  These prefixes may be used in ltxml
           files, particularly for constructors, xpath expressions, etc.  They are not necessarily the  same  as
           the prefixes that will be used in the generated document (See DocType).

       "DocType($rootelement,$publicid,$systemid,%namespaces);"
           Declares  the expected rootelement, the public and system ID's of the document type to be used in the
           final document.  The hash %namespaces specifies the namespaces prefixes that are expected to be found
           in the DTD, along with each associated namespace URI.  Use the  prefix  "#default"  for  the  default
           namespace (ie. the namespace of non-prefixed elements in the DTD).

           The  prefixes defined for the DTD may be different from the prefixes used in implementation CODE (eg.
           in ltxml files; see RegisterNamespace).  The generated document will use the namespaces and  prefixes
           defined for the DTD.

   Document Rewriting
       During  document  construction, as each node gets closed, the text content gets simplfied.  We'll call it
       applying ligatures, for lack of a better name.

       "DefLigature($regexp,%options);"
           Apply the regular expression (given as a string: "/fa/fa/" since it will be converted internally to a
           true regexp), to the text content.  The only option is "fontTest=CODE($font)";  if  given,  then  the
           substitution is applied only when "fontTest" returns true.

           Predefined Ligatures combine sequences of "." or single-quotes into appropriate Unicode characters.

       "DefMathLigature(CODE($document,@nodes));"
           CODE is called on each sequence of math nodes at a given level.  If they should be replaced, return a
           list of "($n,$string,%attributes)" to replace the text content of the first node with $string content
           and  add  the given attributes.  The next "$n-1" nodes are removed.  If no replacement is called for,
           CODE should return undef.

           Predefined Math Ligatures combine letter or digit Math Tokens (XMTok) into multicharacter symbols  or
           numbers, depending on the font (non math italic).

       After document construction, various rewriting and augmenting of the document can take place.

       "DefRewrite(%specification);"
       "DefMathRewrite(%specification);"
           These  two  declarations define document rewrite rules that are applied to the document tree after it
           has been  constructed,  but  before  math  parsing,  or  any  other  postprocessing,  is  done.   The
           %specification  consists  of  a  seqeuence  of  key/value  pairs  with the initial specs successively
           narrowing the selection of document nodes, and the  remaining  specs  indicating  how  to  modify  or
           replace the selected nodes.

           The following select portions of the document:

           label =>$label
               Selects the part of the document with label=$label

           scope =>$scope
               The  $scope  could be "label:foo" or "section:1.2.3" or something similar. These select a subtree
               labelled 'foo', or a section with reference number "1.2.3"

           xpath =>$xpath
               Select those nodes matching an explicit xpath expression.

           match =>$TeX
               Selects nodes that look like what the processing of $TeX would produce.

           regexp=>$regexp
               Selects text nodes that match the regular expression.

           The following act upon the selected node:

           attributes => $hash
               Adds the attributes given in the hash reference to the node.

           replace =>$replacement
               Interprets the $replacement as TeX code to generate nodes that will replace the selected nodes.

   Mid-Level support
       "$tokens = Expand($tokens);"
           Expands the given $tokens according to current definitions.

       "$boxes = Digest($tokens);"
           Processes and digestes the $tokens.  Any arguments needed by control sequences  in  $tokens  must  be
           contained within the $tokens itself.

       "@tokens = Invocation($cs,@args);"
           Constructs a sequence of tokens that would invoke the token $cs on the arguments.

       "RawTeX('... tex code ...');"
           RawTeX  is  a  convenience  function  for  including  chunks  of raw TeX (or LaTeX) code in a Package
           implementation.  It is useful for copying portions of the normal implementation that can  be  handled
           simply using macros and primitives.

       "Let($token1,$token2);"
           Gives $token1 the same `meaning' (definition) as $token2; like TeX's \let.

   Argument Readers
       "ReadParameters($gullet,$spec);"
           Reads from $gullet the tokens corresponding to $spec (a Parameters object).

       "DefParameterType($type,CODE($gullet,@values),%options);"
           Defines a new Parameter type, $type, with CODE for its reader.

           Options are:

           reversion=>CODE($arg,@values);
               This  CODE  is  responsible  for  converting a previously parsed argument back into a sequence of
               Token's.

           optional=>boolean
               whether it is an error if no matching input is found.

           novalue=>boolean
               whether the value returned should contribute to argument lists, or simply be passed over.

           semiverbatim=>boolean
               whether the catcode table should be modified before reading tokens.

       "DefColumnType($proto,$expansion);"
           Defines a new column type for tabular and arrays.  $proto is the prototype for the pattern, analogous
           to the pattern used for other definitions, except that macro being defined  is  a  single  character.
           The  $expansion  is  a  string  specifying  what it should expand into, typically more verbose column
           specification.

   Access to State
       "$value = LookupValue($name);"
           Lookup the current value associated with the the string $name.

       "AssignValue($name,$value,$scope);"
           Assign $value to be associated with the the string $name, according to the given scoping rule.

           Values are also used to specify most configuration parameters (which can therefor  also  be  scoped).
           The recognized configuration parameters are:

            VERBOSITY         : the level of verbosity for debugging
                                output, with 0 being default.
            STRICT            : whether errors (eg. undefined macros)
                                are fatal.
            INCLUDE_COMMENTS  : whether to preserve comments in the
                                source, and to add occasional line
                                number comments. (Default true).
            PRESERVE_NEWLINES : whether newlines in the source should
                                be preserved (not 100% TeX-like).
                                By default this is true.
            SEARCHPATHS       : a list of directories to search for
                                sources, implementations, etc.

       "PushValue($type,$name,@values);"
           This  is  like  "AssignValue",  but  pushes  values onto the end of the value, which should be a LIST
           reference.  Scoping is not handled here (yet?), it simply pushes the value onto the last  binding  of
           $name.

       "UnshiftValue($type,$name,@values);"
           Similar  to   "PushValue",  but  pushes  a value onto the front of the values, which should be a LIST
           reference.

       "$value = LookupCatcode($char);"
           Lookup the current catcode associated with the the character $char.

       "AssignCatcode($char,$catcode,$scope);"
           Set $char to have the given $catcode, with the assignment made according to the given scoping rule.

           This method is also used to specify whether a given character  is  active  in  math  mode,  by  using
           "math:$char" for the character, and using a value of 1 to specify that it is active.

       "$meaning = LookupMeaning($token);"
           Looks  up  the  current  meaning of the given $token which may be a Definition, another token, or the
           token itself if it has not otherwise been defined.

       "$defn = LookupDefinition($token);"
           Looks up the current definition, if any, of the $token.

       "InstallDefinition($defn);"
           Install the Definition $defn into $STATE under its control sequence.

   Low-level Functions
       "CleanLabel($label,$prefix);"
           Cleans a $label of disallowed characters, prepending $prefix (or "LABEL", if none given).

       "CleanIndexKey($key);"
           Cleans an index key, so it can be used as an ID.

       "CleanBibKey($key);"
           Cleans a bibliographic citation key, so it can be used as an ID.

       "CleanURL($url);"
           Cleans a url.

       "UTF($code);"
           Generates a UTF character, handy for the the 8 bit characters.  For  example,  "UTF(0xA0)"  generates
           the non-breaking space.

       "MergeFont(%style);"
           Set  the current font by merging the font style attributes with the current font.  The attributes and
           likely values (the values aren't required to be in this set):

            family : serif, sansserif, typewriter, caligraphic,
                     fraktur, script
            series : medium, bold
            shape  : upright, italic, slanted, smallcaps
            size   : tiny, footnote, small, normal, large,
                     Large, LARGE, huge, Huge
            color  : any named color, default is black

           Some families will only be used in math.  This function returns nothing so it can be easily  used  in
           beforeDigest, afterDigest.

       "@tokens = roman($number);"
           Formats the $number in (lowercase) roman numerals, returning a list of the tokens.

       "@tokens = Roman($number);"
           Formats the $number in (uppercase) roman numerals, returning a list of the tokens.

AUTHOR

       Bruce Miller <bruce.miller@nist.gov>

COPYRIGHT

       Public  domain  software,  produced as part of work done by the United States Government & not subject to
       copyright in the US.

perl v5.10.1                                       2009-06-16                              LaTeXML::Package(3pm)