use IO::File;

my (%classes, %graph);

read_classes(IO::File->new("test.ppl"), \%classes);
read_graph(IO::File->new("test.gr"), \%graph);

use Data::Dumper;
print Dumper \%classes;
print Dumper \%graph;

sub read_classes {
    my ($input, $classes) = @_;

    while (1) {
	chomp(my $proto = <$input>);
	return unless $proto;

	my ($class_state, @args) = split /\s/, $proto;
	my $code = "";
	while (1) {
	    my $line = <$input>;
	    last if !$line || $line =~ /^$/s;
	    $code .= $line;
	}
	my %arg_type_by_name;
	for my $arg (@args) {
	    my ($arg_type, $arg_name) = $arg =~ /^([<>\.])(\w+)$/;
	    die "invalid argument $arg" unless defined $arg_name;
	    $arg_type_by_name{$arg_name} = $arg_type;
	}
	my $args = join ' ', map "$arg_type_by_name{$_}$_", sort keys %arg_type_by_name;
	$classes->{$class_state}{$args} = $code;
    }
}

sub read_graph {
    my ($input, $graph) = @_;

    # read instances
    while (1) {
	chomp (my $decl = <$input>);
	last unless $decl;

	my ($instance, $class_state) = split /\s/, $decl;
	$graph->{$instance} = bless {}, $class_state; # make an instance?
    }

    # read links
    while (1) {
	chomp (my $link = <$input>);
	last unless $link;

	my @nodes = split /\s=\s/, $link;

	my $value;
	# the last term can be the name of an instance, a literal, or a normal term
	if ($nodes[-1] =~ /^[a-zA-Z]\w*(\.[a-zA-Z]\w*)+$/) { }
	elsif ($nodes[-1] =~ /^[a-zA-Z]\w*$/) {
	    # must be an instance
	    $value = $graph->{pop @nodes};
	} else {
	    # must be a literal
	    $value = eval pop @nodes;
	}

	for my $node (@nodes) {
	    my ($instance, $arg) = split /\./, $node;
	    $graph->{$instance}{$arg} = \$value;
	}
    }
}