Here are some more details:
I just copied the example script from the synopsis section and changed the
$input:
#!perl
use strict;
use warnings;
use Marpa::R2;
my $dsl = <<'END_OF_DSL';
:default ::= action => [name,values]
lexeme default = latm => 1
Expression ::= Term action => ::first
Term ::=
Factor action => ::first
| Term '+' Term action => do_add
Factor ::=
Number action => ::first
| Factor '*' Factor action => do_multiply
Number ~ digits
digits ~ [\d]+
:discard ~ whitespace
whitespace ~ [\s]+
END_OF_DSL
my $grammar = Marpa::R2::Scanless::G->new( { source => \$dsl } );
my $input = '1 + 1 + 1';
my $value_ref = $grammar->parse( \$input, 'My_Actions' );
sub My_Actions::do_add {
my ( undef, $t1, undef, $t2 ) = @_;
return $t1 + $t2;
}
sub My_Actions::do_multiply {
my ( undef, $t1, undef, $t2 ) = @_;
return $t1 * $t2;
}
The result looks like this:
Parse of the input is ambiguous
> Length of symbol "Term" at line 1, column 1 is ambiguous
> Choices start with: 1
> Choice 1, length=5, ends at line 1, column 5
> Choice 1: 1 + 1
> Choice 2, length=1, ends at line 1, column 1
> Choice 2: 1
> Marpa::R2 exception at
> D:\Users\root\Documents\Perl\Skripten\Marpa\synopsis.pl line 26.
>
I also found this blog post but I didn't get to work it so far:
http://blogs.perl.org/users/jeffrey_kegler/2012/08/precedence-parsing-made-simpler.html
--
You received this message because you are subscribed to the Google Groups
"marpa parser" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
