add a lot of new stuff

api/util.php

@@ -0,0 +1,132 @@
+<?php
+
+/*
+
+    Brainfuck interpreter in PHP
+    Copyright (C) 2002 Daniel Lorch
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+*/
+
+/******************************************************
+  Some tools which I created and you might find useful
+ ******************************************************/
+
+/*
+  fuck_text() generates brainfuck code from $text. The resulting code will use the current
+  register p for looping and the register p+1 for the resulting character. Thus, make sure
+  these two registers are zero (prepend "[-]>[-]<<" to clear the first two registers).
+  
+  I suggest you to use this function in conjunction with wordwrap:
+  
+    $bf = wordwrap(fuck_text("Hello World"), 75, "\n", 1));
+	
+  wich will generate nice, formatted output.
+*/
+
+function fuck_text($text) {
+  /* value of current pointer */
+  $value = 0;
+
+  for($_t = 0; $_t < strlen($text); ++$_t) {
+
+	/* ordinal difference between current char and the one we want to have */
+	$diff  = ord($text[$_t]) - $value;
+
+	/* it's easier like this than always computing this value - saves some cpu cycles*/
+	$value = ord($text[$_t]);
+
+	/* repeat current character */
+	if($diff == 0) {
+      $result .= ">.<";
+	  continue;
+	}
+
+    /* is it worth making a loop? 
+	   No. A bunch of + or - consume less space than the loop. */
+    if(abs($diff) < 10) {
+
+      /* output a bunch of + or - */
+	  if($diff > 0)
+	    $result .= ">" . str_repeat("+", $diff);
+	  else if($diff < 0)
+	    $result .= ">" . str_repeat("-", abs($diff));
+
+    }
+	/* Yes, create a loop. This will make the resulting code more compact. */
+	else { 
+
+	  /*  we strictly use ints, as PHP has some bugs with floating point operations 
+	     (even if no division is involved) */
+	  $loop = (int)sqrt(abs($diff));
+
+      /* set loop counter */
+      $result .= str_repeat("+", $loop);
+
+	  /* execute loop, then add reminder */
+	  if($diff > 0) {
+		 $result .= "[->" . str_repeat("+", $loop) . "<]";
+         $result .= ">" . str_repeat("+", $diff - pow($loop, 2));
+      }
+      else if($diff < 0) {
+	     $result .= "[->" . str_repeat("-", $loop) . "<]";
+         $result .= ">" . str_repeat("-", abs($diff) - pow($loop, 2));
+	  }
+
+   } /* end: if loop */
+
+	  $result .= ".<";
+
+  } /* end: for */
+
+  /* cleanup */
+  return str_replace("<>", "", $result);
+}
+
+/*
+  This function checks whether the brackets are balanced. Make sure you get the
+  return value correctly, as 0 means "OK" and not "false":
+
+    positive return value : this many [ too much = this many ] missing
+	zero                  : balanced
+    negatice return value : this many ] too much = this many [ missing
+*/
+
+function bf_brackets_balance($bf) {
+  $histogram = count_chars($bf);
+  return $histogram[91] - $histogram[93];
+}
+
+/*
+  This returns the real number of brainfuck commands when all other characters
+  are ignored.
+*/
+
+function bf_count_chars($bf) {
+  return count(preg_split("/[\[\]+\-<>.,]/", $bf)) - 1;
+}
+
+/*
+  bf_reduce() removes all unnecessary characters from a brainfuck source, only
+  leaving actual instructions left.
+*/
+
+function bf_reduce($bf) {
+  preg_match_all("/[\[\]+\-<>.,]/", $bf, $matches);
+  return join("", $matches[0]);
+}
+
+?>