NAME
Pugs::Grammar::Precedence - Engine for Perl 6 Rule operator precedence
SYNOPSIS
use Pugs::Grammar::Precedence;
# example definition for "sub rxinfix:<|> ..."
my $rxinfix = Pugs::Grammar::Precedence->new(
grammar => 'rxinfix',
);
$rxinfix->add_op(
name => '|',
assoc => 'left',
fixity => 'infix',
);Pseudo-code for usage inside a grammar:
sub new_proto( $match ) {
return ${$match<category>}.add_op(
name => $match<name>,
fixity => ...,
precedence => ...,
);
}
rule prototype {
proto <category>:<name> <options>
{
return new_proto($/);
}
}
rule statement {
<category.parse> ...
}DESCRIPTION
This module provides an implementation for Perl 6 operator precedence.
METHODS
new ()
Class method. Returns a category object.
options:
grammar => $category_name- the name of this category (a namespace or a Grammar name).
add_op ()
Instance method. Adds a new operator to the category.
options:
name => $operator_name - the name of this operator, such as '+', '*'
name2 => $operator_name - the name of the second operator in an operator pair, such as circumfix [ '(', ')' ] or ternary [ '??', '!!' ].
# precedence=>'tighter', # tighter/looser/equiv # other=>'+', # fixity => # infix/prefix/circumfix/postcircumfix/ternary # assoc => # left/right/non/chain/list # rule=>$rule # (is parsed)
AUTHORS
The Pugs Team <perl6-compiler@perl.org>.
SEE ALSO
Summary of Perl 6 Operators: http://dev.perl.org/perl6/doc/design/syn/S03.html
COPYRIGHT
Copyright 2006, 2007 by Flavio Soibelmann Glock and others.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.