#!/usr/bin/perl -w use strict; use Test::More tests => 3; use_ok qw(Parse::Eyapp) or exit; use Data::Dumper; use_ok qw( Parse::Eyapp::Treeregexp) or exit; my $grammar = q{ %{ use Data::Dumper; %} %right '=' %left '-' '+' %left '*' '/' %left NEG %tree %% line: exp { $_[1] } ; exp: %name NUM NUM | %name VAR VAR | %name ASSIGN VAR '=' exp | %name PLUS exp '+' exp | %name MINUS exp '-' exp | %name TIMES exp '*' exp | %name DIV exp '/' exp | %name UMINUS '-' exp %prec NEG | '(' exp ')' { $_[2] } /* Let us simplify a bit the tree */ ; %% sub _Error { exists $_[0]->YYData->{ERRMSG} and do { print $_[0]->YYData->{ERRMSG}; delete $_[0]->YYData->{ERRMSG}; return; }; print "Syntax error.\n"; } sub _Lexer { my($parser)=shift; $parser->YYData->{INPUT} or $parser->YYData->{INPUT} = <STDIN> or return('',undef); $parser->YYData->{INPUT}=~s/^\s+//; for ($parser->YYData->{INPUT}) { s/^([0-9]+(?:\.[0-9]+)?)// and return('NUM',$1); s/^([A-Za-z][A-Za-z0-9_]*)// and return('VAR',$1); s/^(.)//s and return($1,$1); } } sub Run { my($self)=shift; $self->YYParse( yylex => \&_Lexer, yyerror => \&_Error, #yydebug =>0xFF ); } }; # end grammar our (@all, $uminus, $constantfold, $zero_times_whatever, $whatever_times_zero); $Data::Dumper::Indent = 1; Parse::Eyapp->new_grammar(input=>$grammar, classname=>'Rule6'); my $parser = Rule6->new(); $parser->YYData->{INPUT} = "2*3\n"; my $t = $parser->Run; print "\n***** Before ******\n"; print Dumper($t); my $p = Parse::Eyapp::Treeregexp->new( STRING => q{ { my %Op = (PLUS=>'+', MINUS => '-', TIMES=>'*', DIV => '/'); } constantfold: /TIMES|PLUS|MINUS|DIV/(NUM($x), NUM($y)) => { my $op = $Op{ref($_[0])}; my $res = Parse::Eyapp::Node->new( q{NUM(TERMINAL)}, sub { my ($NUM, $TERMINAL) = @_; $TERMINAL->{attr} = eval "$x->{attr} $op $y->{attr}"; $TERMINAL->{token} = 'NUM'; print Dumper($NUM); }, ); print "$x->{attr} * $y->{attr}\n"; print Dumper($res); $_[0] = $res; } }, #OUTPUTFILE => 'main.pm', ); $p->generate(); $constantfold->s($t); print "\n***** After: The tree for 2*3 has been simplified to the tree for 6 ******\n"; print Dumper($t); my $expected_result = bless( { 'children' => [ bless( { 'children' => [], 'attr' => 6, 'token' => 'NUM' }, 'TERMINAL' ) ] }, 'NUM' ); is_deeply($t, $expected_result, 'Simplify tree with vars and several families');