#####################################################################
# This scripts process Literate Haskell Script itself to be process 
#   by lhs2TeX with haddock comments. 
#

use strict;
use warnings;

my @tag=();

while (<>) {
    if ($_ =~ /\\begin{(.*)}/) {push @tag => $1;}
    
    if ( elem("code",@tag) and /(.*)--(.*)/) {
        print $1 => '--' => 
#            "\\begin{verbatim}" => $2 => "\\end{verbatim}" => "\n";
            process($2) => "\n";
    }
    elsif (elem("nocode",@tag)) {;}
    else {
        print;
    }
    if ($_ =~ /\\end{(.*)}/ and $1 eq $tag[@tag-1]) {pop @tag;}
}

#####################################################################

#######################################
sub process{
    my ($input) = @_;
    $input =~ s/\\/\$\\backslash\$/g;
    $input =~ s/\|/\|\|/g;
    $input =~ s/\@/\@\@/g;
    $input =~ s/\^//g;
    $input =~ s/\"/\'/g;
    $input =~ s/_/\\_/g;
    return $input;
}

#######################################
sub elem {
    my ($x,@xs) = @_;
    my $res = 0;
    for (@xs) {$res=1 if $x eq $_}
    return $res;
}