PPI::Lexer(3) User Contributed Perl Documentation PPI::Lexer(3)NAMEPPI::Lexer - The PPI Lexer
SYNOPSIS
use PPI;
# Create a new Lexer
my $Lexer = PPI::Lexer->new;
# Build a PPI::Document object from a Token stream
my $Tokenizer = PPI::Tokenizer->load('My/Module.pm');
my $Document = $Lexer->lex_tokenizer($Tokenizer);
# Build a PPI::Document object for some raw source
my $source = "print 'Hello World!'; kill(Humans->all);";
$Document = $Lexer->lex_source($source);
# Build a PPI::Document object for a particular file name
$Document = $Lexer->lex_file('My/Module.pm');
DESCRIPTION
The is the PPI Lexer. In the larger scheme of things, its job is to
take token streams, in a variety of forms, and "lex" them into nested
structures.
Pretty much everything in this module happens behind the scenes at this
point. In fact, at the moment you don't really need to instantiate the
lexer at all, the three main methods will auto-instantiate themselves a
"PPI::Lexer" object as needed.
All methods do a one-shot "lex this and give me a PPI::Document
object".
In fact, if you are reading this, what you probably want to do is to
just "load a document", in which case you can do this in a much more
direct and concise manner with one of the following.
use PPI;
$Document = PPI::Document->load( $filename );
$Document = PPI::Document->new( $string );
See PPI::Document for more details.
For more unusual tasks, by all means forge onwards.
METHODS
new
The "new" constructor creates a new "PPI::Lexer" object. The object
itself is merely used to hold various buffers and state data during the
lexing process, and holds no significant data between ->lex_xxxxx
calls.
Returns a new "PPI::Lexer" object
lex_file $filename
The "lex_file" method takes a filename as argument. It then loads the
file, creates a PPI::Tokenizer for the content and lexes the token
stream produced by the tokenizer. Basically, a sort of all-in-one
method for getting a PPI::Document object from a file name.
Returns a PPI::Document object, or "undef" on error.
lex_source $string
The "lex_source" method takes a normal scalar string as argument. It
creates a PPI::Tokenizer object for the string, and then lexes the
resulting token stream.
Returns a PPI::Document object, or "undef" on error.
lex_tokenizer $Tokenizer
The "lex_tokenizer" takes as argument a PPI::Tokenizer object. It lexes
the token stream from the tokenizer into a PPI::Document object.
Returns a PPI::Document object, or "undef" on error.
errstr
For any error that occurs, you can use the "errstr", as either a static
or object method, to access the error message.
If no error occurs for any particular action, "errstr" will return
false.
TO DO
- Add optional support for some of the more common source filters
- Some additional checks for blessing things into various Statement and
Structure subclasses.
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.
perl v5.16.2 2011-02-25 PPI::Lexer(3)
