NAME

       XML::Easy::Classify - classification of XML-related items

SYNOPSIS

           use XML::Easy::Classify qw(
               is_xml_name check_xml_name
               is_xml_encname check_xml_encname
               is_xml_chardata check_xml_chardata
               is_xml_attributes check_xml_attributes
               is_xml_content_object check_xml_content_object
               is_xml_content_twine check_xml_content_twine
               is_xml_content check_xml_content
               is_xml_element check_xml_element);

           if(is_xml_name($arg)) { ...
           check_xml_name($arg);
           if(is_xml_encname($arg)) { ...
           check_xml_encname($arg);
           if(is_xml_chardata($arg)) { ...
           check_xml_chardata($arg);

           if(is_xml_attributes($arg)) { ...
           check_xml_attributes($arg);

           if(is_xml_content_object($arg)) { ...
           check_xml_content_object($arg);
           if(is_xml_content_twine($arg)) { ...
           check_xml_content_twine($arg);
           if(is_xml_content($arg)) { ...
           check_xml_content($arg);

           if(is_xml_element($arg)) { ...
           check_xml_element($arg);

DESCRIPTION

       This module provides various type-testing functions, relating to data types used in the
       XML::Easy ensemble.  These are mainly intended to be used to enforce validity of data
       being processed by XML-related functions.

       There are two flavours of function in this module.  Functions of the first flavour only
       provide type classification, to allow code to discriminate between argument types.
       Functions of the second flavour package up the most common type of type discrimination:
       checking that an argument is of an expected type.  The functions come in matched pairs.

FUNCTIONS

       Each of these functions takes one scalar argument (ARG) to be tested.  Any scalar value is
       acceptable for the argument to be tested.  Each "is_" function returns a simple truth
       value result, which is true iff ARG is of the type being checked for.  Each "check_"
       function will return normally if the argument is of the type being checked for, or will
       "die" if it is not.

       is_xml_name(ARG)
       check_xml_name(ARG)
           Check whether ARG is a plain string satisfying the XML name syntax.  (Such names are
           used to identify element types, attributes, entities, and other things in XML.)

       is_xml_encname(ARG)
       check_xml_encname(ARG)
           Check whether ARG is a plain string satisfying the XML character encoding name syntax.

       is_xml_chardata(ARG)
       check_xml_chardata(ARG)
           Check whether ARG is a plain string consisting of a sequence of characters that are
           acceptable to XML.  Such a string is valid as data in an XML element (where it may be
           intermingled with subelements) or as the value of an element attribute.

       is_xml_attributes(ARG)
       check_xml_attributes(ARG)
           Check whether ARG is a reference to a hash that is well-formed as an XML element
           attribute set.  To be well-formed, each key in the hash must be an XML name string,
           and each value must be an XML character data string.

       is_xml_content_object(ARG)
       check_xml_content_object(ARG)
           Check whether ARG is a reference to an XML::Easy::Content object, and thus represents
           a chunk of XML content.

       is_xml_content_twine(ARG)
       check_xml_content_twine(ARG)
           Check whether ARG is a reference to a twine array (see "Twine" in
           XML::Easy::NodeBasics), and thus represents a chunk of XML content.

       is_xml_content_array(ARG)
           Deprecated alias for "is_xml_content_twine".

       is_xml_content(ARG)
       check_xml_content(ARG)
           Check whether ARG is a reference to either an XML::Easy::Content object or a twine
           array (see "Twine" in XML::Easy::NodeBasics), and thus represents a chunk of XML
           content.

       is_xml_element(ARG)
       check_xml_element(ARG)
           Check whether ARG is a reference to an XML::Easy::Element object, and thus represents
           an XML element.

SEE ALSO

       Params::Classify, XML::Easy::NodeBasics

AUTHOR

       Andrew Main (Zefram) <zefram@fysh.org>

COPYRIGHT

       Copyright (C) 2009, 2010, 2011, 2017 Andrew Main (Zefram) <zefram@fysh.org>

LICENSE

       This module is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.