bionic (3) PPI::Statement.3pm.gz

Provided by: libppi-perl_1.236-1_all bug

NAME

       PPI::Statement - The base class for Perl statements

INHERITANCE

         PPI::Statement
         isa PPI::Node
             isa PPI::Element

DESCRIPTION

       PPI::Statement is the root class for all Perl statements. This includes (from perlsyn) "Declarations",
       "Simple Statements" and "Compound Statements".

       The class PPI::Statement itself represents a "Simple Statement" as defined in the perlsyn manpage.

STATEMENT CLASSES

       Please note that unless documented themselves, these classes are yet to be frozen/finalised. Names may
       change slightly or be added or removed.

   PPI::Statement::Scheduled
       This covers all "scheduled" blocks, chunks of code that are executed separately from the main body of the
       code, at a particular time. This includes all "BEGIN", "CHECK", "UNITCHECK", "INIT" and "END" blocks.

   PPI::Statement::Package
       A package declaration, as defined in perlfunc.

   PPI::Statement::Include
       A statement that loads or unloads another module.

       This includes 'use', 'no', and 'require' statements.

   PPI::Statement::Sub
       A named subroutine declaration, or forward declaration

   PPI::Statement::Variable
       A variable declaration statement. This could be either a straight declaration or also be an expression.

       This includes all 'my', 'state', 'local' and 'our' statements.

   PPI::Statement::Compound
       This covers the whole family of 'compound' statements, as described in perlsyn.

       This includes all statements starting with 'if', 'unless', 'for', 'foreach' and 'while'. Note that this
       does NOT include 'do', as it is treated differently.

       All compound statements have implicit ends. That is, they do not end with a ';' statement terminator.

   PPI::Statement::Break
       A statement that breaks out of a structure.

       This includes all of 'redo', 'goto', 'next', 'last' and 'return' statements.

   PPI::Statement::Given
       The kind of statement introduced in Perl 5.10 that starts with 'given'.  This has an implicit end.

   PPI::Statement::When
       The kind of statement introduced in Perl 5.10 that starts with 'when' or 'default'.  This also has an
       implicit end.

   PPI::Statement::Data
       A special statement which encompasses an entire "__DATA__" block, including the initial '__DATA__' token
       itself and the entire contents.

   PPI::Statement::End
       A special statement which encompasses an entire __END__ block, including the initial '__END__' token
       itself and the entire contents, including any parsed PPI::Token::POD that may occur in it.

   PPI::Statement::Expression
       PPI::Statement::Expression is a little more speculative, and is intended to help represent the special
       rules relating to "expressions" such as in:

         # Several examples of expression statements

         # Boolean conditions
         if ( expression ) { ... }

         # Lists, such as for arguments
         Foo->bar( expression )

   PPI::Statement::Null
       A null statement is a special case for where we encounter two consecutive statement terminators. ( ;; )

       The second terminator is given an entire statement of its own, but one that serves no purpose. Hence a
       'null' statement.

       Theoretically, assuming a correct parsing of a perl file, all null statements are superfluous and should
       be able to be removed without damage to the file.

       But don't do that, in case PPI has parsed something wrong.

   PPI::Statement::UnmatchedBrace
       Because PPI is intended for use when parsing incorrect or incomplete code, the problem arises of what to
       do with a stray closing brace.

       Rather than die, it is allocated its own "unmatched brace" statement, which really means "unmatched
       closing brace". An unmatched open brace at the end of a file would become a structure with no contents
       and no closing brace.

       If the document loaded is intended to be correct and valid, finding a PPI::Statement::UnmatchedBrace in
       the PDOM is generally indicative of a misparse.

   PPI::Statement::Unknown
       This is used temporarily mid-parsing to hold statements for which the lexer cannot yet determine what
       class it should be, usually because there are insufficient clues, or it might be more than one thing.

       You should never encounter these in a fully parsed PDOM tree.

METHODS

       "PPI::Statement" itself has very few methods. Most of the time, you will be working with the more generic
       PPI::Element or PPI::Node methods, or one of the methods that are subclass-specific.

   label
       One factor common to most statements is their ability to be labeled.

       The "label" method returns the label for a statement, if one has been defined, but without the trailing
       colon. Take the following example

         MYLABEL: while ( 1 .. 10 ) { last MYLABEL if $_ > 5 }

       For the above statement, the "label" method would return 'MYLABEL'.

       Returns false if the statement does not have a label.

   specialized
       Answer whether this is a plain statement or one that has more significance.

       Returns true if the statement is a subclass of this one, false otherwise.

   stable
       Much like the PPI::Document method of the same name, the ->stable method converts a statement to source
       and back again, to determine if a modified statement is still legal, and won't be interpreted in a
       different way.

       Returns true if the statement is stable, false if not, or "undef" on error.

TO DO

       - Complete, freeze and document the remaining classes

SUPPORT

       See the support section in the main module.

AUTHOR

       Adam Kennedy <adamk@cpan.org>

       Copyright 2001 - 2011 Adam Kennedy.

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

       The full text of the license can be found in the LICENSE file included with this module.