#!/usr/bin/perl -w

#  l00p.pl : A compiler for the esoteric programming language "L00P".
#  Author  : Georg Westenberger  ( gwestenb@gmx.de  )
#  usage    : perl l00p.pl [infile [outfile]]  
#



#-------------------- BEGIN C HEREDOC --------------------------------

my $decl = <<END;
#include <stdio.h>

#define ARRAYSIZE 8192
signed short a[ARRAYSIZE];
signed short p = 0;

signed short wrap (signed short ptr)
{
  if (ptr>=0) return (ptr % ARRAYSIZE);
  else return (-ptr/ARRAYSIZE+1)*ARRAYSIZE+ptr;
}

#define A a[p]
#define _a(x) a[wrap(x)]


#define out_c printf("%c",a[p])
#define in_c  scanf("%c",a+p)
#define out_d printf("%d",a[p])
#define in_d scanf("%d",a+p)

int main() { 
int i;
for (i=0;i<ARRAYSIZE;i++) a[i]=0;
while(1){

END

#-------------------- END C HEREDOC ----------------------------------






my %translation = (
'-' => 'A--;',
'+' => 'A++;',
'<' => 'p = wrap(p-1);',
'>' => 'p = wrap(p+1);',
',' => 'in_c;',
'.' => 'out_c;',
';' => 'in_d;',
':' => 'out_d;',
'&' => 'break;',
'*' => 'A*=2;',
'0' => 'A=0;',
'_' => 'A=-A;',
'@' => 'A=_a(p+_a(p));',
'#' => 'p=wrap(p+_a(p));',
'$' => '_a(p+_a(p))=A;',
'(' => 'if(A){',
'|' => '}else{',
')' => '}',
'[' => 'if(!A){',
']' => '}',
'S' => 'A= A>0 ? 1:(A<0 ? -1 : 0);'
);

sub check_syntax
{
  my $s = shift;
  $s =~s-[^\[\]\(\)\|]--g;
  while ($s=~s-(?:\[\|??\])|(?:\(\|??\))--g) {};
  die "\n||| SYNTAX ERROR: reduces to $s\n" unless ($s eq '');
}

my $prog = '';
my $nsf = shift @ARGV;     # Name of Source File, stdin by default
$nsf ||= '-';
open SRC,$nsf or die "Can't open '$nsf'!\n";
while (defined($l=<SRC>))
{
  chomp $l;
  $l=~s[\s][]g;
  $l=~s[//.*$][];
	$l=~s-(?:\s+|[^\-\+\<\>\*0\_\@\#\$\&\(\)\|\[\]\,\.\;\:]+)--g;
  $prog .= $l;
}

close SRC;

check_syntax $prog;

my $ncf = shift @ARGV;
$ncf ||= '-';
open CSRC, ">$ncf" or die "Can't open '$ncf'!\n";
print CSRC $decl;

my @l = map{$_=$translation{$_}} (split '',$prog);
foreach $x (@l) { print CSRC $x."\n" };
print CSRC '}}';

close CSRC;