# Grammar can be in text or tree form. Tree will be compiled from text.
# Grammar can also be stored in a file.
has file => ();
has text => (
builder => 'make_text',
lazy => 1,
);
has tree => (
builder => 'make_tree',
lazy => 1,
);
has start_rules => [];
sub make_text {
my ($self) = @_;
my $filename = $self->file
or return '';
open TEXT, $filename
or die "Can't open '$filename' for input\n:$!";
return do {local $/; <TEXT>}
}
sub make_tree {
my ($self) = @_;
my $text = $self->text
or die "Can't create a '" . ref($self) .
"' grammar. No tree or text or file.";
require Pegex::Compiler;
return Pegex::Compiler->new->compile(
$text,
@{$self->start_rules || []}
)->tree;
}
# This import is to support: perl -MPegex::Grammar::Module=compile
sub import {
my ($package) = @_;
if (((caller))[1] =~ /^-e?$/ and @_ == 2 and $_[1] eq 'compile') {
$package->compile_into_module();
exit;
}
if (my $env = $ENV{PERL_PEGEX_AUTO_COMPILE}) {
my %modules = map {($_, 1)} split ',', $env;
if ($modules{$package}) {
if (my $grammar_file = $package->file) {
if (-f $grammar_file) {
my $module = $package;
$module =~ s!::!/!g;
$module .= '.pm';
my $module_file = $INC{$module};
if (-M $grammar_file < -M $module_file) {
$package->compile_into_module();
local $SIG{__WARN__};
delete $INC{$module};
require $module;
}
}
}
}
}
}
sub compile_into_module {
my ($package) = @_;
my $grammar_file = $package->file;
open GRAMMAR, $grammar_file
or die "Can't open $grammar_file for input";
my $grammar_text = do {local $/; <GRAMMAR>};
close GRAMMAR;
my $module = $package;
$module =~ s!::!/!g;
$module = "$module.pm";
my $file = $INC{$module} or return;
my $perl;
my @rules;
if ($package->can('start_rules')) {
@rules = @{$package->start_rules || []};
}
if ($module eq 'Pegex/Pegex/Grammar.pm') {
$perl = Pegex::Bootstrap->new->compile($grammar_text, @rules)->to_perl;
}
else {
require Pegex::Compiler;
$perl = Pegex::Compiler->new->compile($grammar_text, @rules)->to_perl;
}
open IN, $file or die $!;
my $module_text = do {local $/; <IN>};
require Pegex;
my $msg = " # Generated/Inlined by Pegex::Grammar ($Pegex::VERSION)";
close IN;
$perl =~ s/^/ /gm;
$module_text =~ s/^(sub\s+make_tree\s*\{).*?(^\})/$1$msg\n$perl$2/ms;
$module_text =~ s/^(sub\s+tree\s*\{).*?(^\})/$1$msg\n$perl$2/ms;
chomp $grammar_text;
$grammar_text = "<<'...';\n$grammar_text\n...\n";
$module_text =~ s/^(sub\s+text\s*\{).*?(^\})/$1$msg\n$grammar_text$2/ms;
$grammar_text =~ s/^/# /gm;
$module_text =~ s/^(# sub\s+text\s*\{).*?(^# \})/$1$msg\n$grammar_text$2/ms;
open OUT, '>', $file or die $!;
print OUT $module_text;
close OUT;
print "Compiled '$grammar_file' into '$file'.\n";
}
1;