NAME
Text::Snippet - TextMate-like snippet functionality
VERSION
version 0.04
SYNOPSIS
This module provides TextMate-like snippet functionality via an
editor-agnostic API. The snippet syntax is modeled after the snippets
provided by TextMate.
use Text::Snippet;
my $snippet = Text::Snippet->parse($snippet_content);
my @tabstops = $snippet->tab_stops;
foreach my $t (@tabstops) {
my $replacement = get_user_input(); # get user input somehow
$t->replace($replacement) if ($user_input);
}
print $snippet; # stringify and write to STDOUT
# alternate "cursor" interface
my $cursor = $snippet->cursor;
while ( my $direction = get_user_tab_direction() ) { # forward or backward
my $t;
if ( $direction == 1 ) { # tab
$t = $cursor->next;
} elsif ( $direction == -1 ) { # shift-tab
$t = $cursor->prev;
} else {
last; # bail
}
next if ( !$t );
# get (zero-based) cursor position relative to the beginning of the snippet
my($line, $column) = $cursor->current_position;
my $replacement = get_user_input();
$t->replace($replacement);
}
print $snippet; # stringify snippet and write to STDOUT
SUPPORTED SNIPPET SYNTAX
* Plain text
The simplest snippet is just plain text with no tab stops and is
returned verbatim to the caller.
* Simple tab stops
Tab stops are indications for where the cursor should be placed
after the user inserts a snippet. Simple tab stops are simply a
dollar sign followed by a digit. The special $0 tab stop is terminal
and is where the cursor will end up when the user has progressed
through all other tab stops defined by the snippet. If no $0 tab
stop is indicated, one is added by default right after the final
character of the snippet. A simple "if" snippet (two explicit tab
stops plus an implicit terminal after the closing brace of the "if"
block):
if ($1) {
$2
}
* Tab stops with defaults
Sometimes a snippet may provide a default value to the user to make
the snippet easier to flesh out. These types of tab stops look like
so:
while( my(\$${1:key}, \$${2:value}) = each(%${3:hash}) {
$0
}
While navigating through the tab stops, the first three positions
will provide default values ("key", "value" and "hash"
respectively). The terminal tab stop will leave the cursor in the
body of the "while" block.
* Tab stops with mirroring
Sometimes you may want the value the user entered in one tab stop to
be copied to another. This (in TextMate lingo) is called mirroring.
This is very simple to do, just use the same index on more than one
tab stop and the content entered in the first will automatically be
used in the others. A rather contrived example:
foreach my \$${1:item} (@${2:array}) {
print "$${1}\n";
}
All occurences of the first tab stop (the loop variable and in the
"print" statement) will have the same value (defaulting to "item").
* Transforming tab stops
The most advanced type of tab stop allows you to modify the entered
value on the fly using a regular expression. For instance, if you
like to use "getFoo" and "setFoo" accessors with Moose, you might
use the following snippet:
has ${1:propertyName} => (
is => '${2:rw}',
isa => '${3:Str}',
reader => 'get${1/./\u$0/}),
writer => 'set${1/./\u$0}),
);
If the user leaves all the defaults, the output of this snippet
would be:
has propertyName => (
is => 'rw',
isa => 'Str',
reader => 'getPropertyName',
writer => 'setPropertyName'
);
Another example would be a helper snippet for creating simple HTML
tags:
<${1:a}>${2}</${1/\s.*//}>
The transformer on the mirrored tab stop essentially will truncate
anything starting with the first whitespace character entered by the
first replacement value, the mirrored tab stop will have a
replacement of just "a".
CLASS METHODS
parse
This is the main entry point into this module's functionality. It takes
a single argument, the content of the snippet that conforms to the
syntax described above.
INSTANCE METHODS
to_string
Obviously, gets the full content of the snippet as it currently exists.
This object is overloaded as well so simply printing the object or
including it inside double quotes will have the same effect.
chunks
Returns an ArrayRef that makes up the entire content of the snippet.
Depending on the source of the snippet, some of these items may be
literal scalars (representing static content) and others may be
Text::Snippet::TabStop objects that represent the user-enterable
portions of the snippet.
src
This returns the original source as it was passed to "parse"
tab_stops
This returns an ArrayRef of Text::Snippet::TabStop objects that
represent the user-enterable portions of the snippet. These are ordered
by the tab stop's index with the zero-th index coming last.
cursor
This method creates a Text::Snippet::TabStop::Cursor object for you
which allows the caller to traverse a series of tab stops in a
convenient fashion.
BUGS
Please report any bugs or feature requests to "bug-text-snippet at
rt.cpan.org", or through the web interface at
notified, and then you'll automatically be notified of progress on your
bug as I make changes.
SUPPORT
You can find documentation for this module with the perldoc command.
perldoc Text::Snippet
You can also look for information at:
* RT: CPAN's request tracker
* AnnoCPAN: Annotated CPAN documentation
* CPAN Ratings
* Search CPAN
AUTHOR
Brian Phillips <bphillips@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2010 by Brian Phillips.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.