GSP
Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages


Manual Reference Pages  -  PPI::STATEMENT (3)

.ds Aq ’

NAME

PPI::Statement - The base class for Perl statements

CONTENTS

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

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.

Search for    or go to Top of page |  Section 3 |  Main Index


perl v5.20.3 PPI::STATEMENT (3) 2014-11-11

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with manServer 1.07.