NAME

       Perl::Critic::Utils::PPI - Utility functions for dealing with PPI objects.

DESCRIPTION

       Provides classification of PPI::Elements.

INTERFACE SUPPORT

       This is considered to be a public module.  Any changes to its interface will go through a
       deprecation cycle.

IMPORTABLE SUBS

       "is_ppi_expression_or_generic_statement( $element )"
           Answers whether the parameter is an expression or an undifferentiated statement.  I.e.
           the parameter either is a PPI::Statement::Expression or the class of the parameter is
           PPI::Statement and not one of its subclasses other than "Expression".

       "is_ppi_generic_statement( $element )"
           Answers whether the parameter is an undifferentiated statement, i.e.  the parameter is
           a PPI::Statement but not one of its subclasses.

       "is_ppi_statement_subclass( $element )"
           Answers whether the parameter is a specialized statement, i.e. the parameter is a
           PPI::Statement but the class of the parameter is not PPI::Statement.

       "is_ppi_simple_statement( $element )"
           Answers whether the parameter represents a simple statement, i.e. whether the
           parameter is a PPI::Statement, PPI::Statement::Break, PPI::Statement::Include,
           PPI::Statement::Null, PPI::Statement::Package, or PPI::Statement::Variable.

       "is_ppi_constant_element( $element )"
           Answers whether the parameter represents a constant value, i.e. whether the parameter
           is a PPI::Token::Number, PPI::Token::Quote::Literal, PPI::Token::Quote::Single, or
           PPI::Token::QuoteLike::Words, or is a PPI::Token::Quote::Double or
           PPI::Token::Quote::Interpolate which does not in fact contain any interpolated
           variables.

           This subroutine does not interpret any form of here document as a constant value, and
           may not until PPI::Token::HereDoc acquires the relevant portions of the
           PPI::Token::Quote interface.

           This subroutine also does not interpret entities created by the Readonly module or the
           constant pragma as constants, because the infrastructure to detect these appears not
           to be present, and the author of this subroutine (not Mr. Shank or Mr. Thalhammer)
           lacks the knowledge/expertise/gumption to put it in place.

       "is_subroutine_declaration( $element )"
           Is the parameter a subroutine declaration, named or not?

       "is_in_subroutine( $element )"
           Is the parameter a subroutine or inside one?

       "get_constant_name_element_from_declaring_statement($statement)"
           This subroutine is deprecated. You should use
           "get_constant_name_elements_from_declaring_statement()" in PPIx::Utilities::Statement
           instead.

           Given a PPI::Statement, if the statement is a "use constant" or Readonly declaration
           statement, return the name of the thing being defined.

           Given

               use constant 1.16 FOO => 'bar';

           this will return "FOO".  Similarly, given

               Readonly::Hash my %FOO => ( bar => 'baz' );

           this will return "%FOO".

           Caveat: in the case where multiple constants are declared using the same "use
           constant" statement (e.g. "use constant { FOO => 1, BAR => 2 };", this subroutine will
           return the declaring PPI::Structure::Constructor. In the case of "use constant 1.16 {
           FOO => 1, BAR => 2 };" it may return a PPI::Structure::Block instead of a
           PPI::Structure::Constructor, due to a parse error in PPI.

       "get_next_element_in_same_simple_statement( $element )"
           Given a PPI::Element, this subroutine returns the next element in the same simple
           statement as defined by is_ppi_simple_statement(). If no next element can be found,
           this subroutine simply returns.

           If the $element is undefined or unblessed, we simply return.

           If the $element satisfies "is_ppi_simple_statement()", we return, unless it has a
           parent which is a PPI::Structure::List.

           If the $element is the last significant element in its PPI::Node, we replace it with
           its parent and iterate again.

           Otherwise, we return "$element->snext_sibling()".

       "get_previous_module_used_on_same_line( $element )"
           Given a PPI::Element, returns the PPI::Element representing the name of the module
           included by the previous "use" or "require" on the same line as the $element. If none
           is found, simply returns.

           For example, with the line

               use version; our $VERSION = ...;

           given the PPI::Token::Symbol instance for $VERSION, this will return "version".

           If the given element is in a "use" or <require>, the return is from the previous "use"
           or "require" on the line, if any.

AUTHOR

       Elliot Shank <perl@galumph.com>

COPYRIGHT

       Copyright (c) 2007-2011 Elliot Shank.

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.  The full text of this license can be found in the LICENSE file
       included with this module.