#!/usr/bin/perl use warnings; use strict; use feature qw{ say }; use Marpa::R2; my $dsl = << '__DSL__'; lexeme default = latm => 1 Assignment ::= var ('=') Expression action => ASSIGN Expression ::= var action => VAR | ('(') Expression (')') action => ::first assoc => group || Expression (q) action => NOT || Expression ('*') Expression action => AND || Expression ('+') Expression action => OR q ~ ['] var ~ [A-Z]+ :discard ~ whitespace whitespace ~ [\s]+ __DSL__ my %var; sub ASSIGN { $var{ $_[1] } = 0 + $_[2] } sub NOT { ! $_[1] } sub AND { $_[1] && $_[2] } sub OR { $_[1] || $_[2] } sub VAR { $var{ $_[1] } } my @input = ('Y = A + (B*C)', "Y = A + (B' + (C*D)')", "Y = A*(B*(C'+D)')"); my $grammar = 'Marpa::R2::Scanless::G'->new({ source => \$dsl }); for my $line (@input) { %var = map +( $_ => int rand 2 ), 'A' .. 'D'; my $result = $grammar->parse(\$line, { semantics_package => 'main' }); say join ' ', %var; }