From 3c51baa4167d5a68ff010dc81525b9340c5f1329 Mon Sep 17 00:00:00 2001
From: Kevin Chabowski <kevin@kch42.de>
Date: Sat, 24 May 2014 14:45:13 +0200
Subject: Moved code into src subfolder and fixed docu

---
 Calc.php | 138 ---------------------------------------------------------------
 1 file changed, 138 deletions(-)
 delete mode 100644 Calc.php

(limited to 'Calc.php')

diff --git a/Calc.php b/Calc.php
deleted file mode 100644
index e8dba8d..0000000
--- a/Calc.php
+++ /dev/null
@@ -1,138 +0,0 @@
-<?php
-
-namespace kch42\ste;
-
-/* Class Calc contains static methods needed by <ste:calc /> */
-class Calc {
-	private function __construct() {}
-	
-	/* We could also just eval() the $infix_math code, but this is much cooler :-D (Parser inception) */
-	public static function shunting_yard($infix_math) {
-		$operators = array(
-			"+" => array("l", 2),
-			"-" => array("l", 2),
-			"*" => array("l", 3),
-			"/" => array("l", 3),
-			"^" => array("r", 4),
-			"_" => array("r", 5),
-			"(" => array("", 0), 
-			")" => array("", 0)
-		);
-		
-		preg_match_all("/\s*(?:(?:[+\\-\\*\\/\\^\\(\\)])|(\\d*[\\.]?\\d*))\\s*/s", $infix_math, $tokens, PREG_PATTERN_ORDER);
-		$tokens_raw   = array_filter(array_map('trim', $tokens[0]), function($x) { return ($x === "0") || (!empty($x)); });
-		$output_queue = array();
-		$op_stack     = array();
-		
-		$lastpriority = NULL;
-		/* Make - unary, if neccessary */
-		$tokens = array();
-		foreach($tokens_raw as $token) {
-			$priority = isset($operators[$token]) ? $operators[$token][1] : -1;
-			if(($token == "-") && (($lastpriority === NULL) || ($lastpriority >= 0))) {
-				$priority = $operators["_"][1];
-				$tokens[] = "_";
-			} else {
-				$tokens[] = $token;
-			}
-			$lastpriority = $priority;
-		}
-		
-		while(!empty($tokens)) {
-			$token = array_shift($tokens);
-			if(is_numeric($token)) {
-				$output_queue[] = $token;
-			} else if($token == "(") {
-				$op_stack[] = $token;
-			} else if($token == ")") {
-				$lbr_found = false;
-				while(!empty($op_stack)) {
-					$op = array_pop($op_stack);
-					if($op == "(") {
-						$lbr_found = true;
-						break;
-					}
-					$output_queue[] = $op;
-				}
-				if(!$lbr_found) {
-					throw new RuntimeError("Bracket mismatch.");
-				}
-			} else if(!isset($operators[$token])) {
-				throw new RuntimeError("Invalid token ($token): Not a number, bracket or operator. Stop.");
-			} else {
-				$priority = $operators[$token][1];
-				if($operators[$token][0] == "l") {
-					while((!empty($op_stack)) and ($priority <= $operators[$op_stack[count($op_stack)-1]][1])) {
-						$output_queue[] = array_pop($op_stack);
-					}
-				} else {
-					while((!empty($op_stack)) and ($priority < $operators[$op_stack[count($op_stack)-1]][1])) {
-						$output_queue[] = array_pop($op_stack);
-					}
-				}
-				$op_stack[] = $token;
-			}
-		}
-		
-		while(!empty($op_stack)) {
-			$op = array_pop($op_stack);
-			if($op == "(") {
-				throw new RuntimeError("Bracket mismatch...");
-			}
-			$output_queue[] = $op;
-		}
-		
-		return $output_queue;
-	}
-	
-	public static function pop2(&$array) {
-		$rv = array(array_pop($array), array_pop($array));
-		if(array_search(NULL, $rv, true) !== false) {
-			throw new RuntimeError("Not enough numbers on stack. Invalid formula.");
-		}
-		return $rv;
-	}
-	
-	public static function calc_rpn($rpn) {
-		$stack = array();
-		foreach($rpn as $token) {
-			switch($token) {
-			case "+":
-				list($b, $a) = self::pop2($stack);
-				$stack[] = $a + $b;
-				break;
-			case "-":
-				list($b, $a) = self::pop2($stack);
-				$stack[] = $a - $b;
-				break;
-			case "*":
-				list($b, $a) = self::pop2($stack);
-				$stack[] = $a * $b;
-				break;
-			case "/":
-				list($b, $a) = self::pop2($stack);
-				$stack[] = $a / $b;
-				break;
-			case "^":
-				list($b, $a) = self::pop2($stack);
-				$stack[] = pow($a, $b);
-				break;
-			case "_":
-				$a = array_pop($stack);
-				if($a === NULL) {
-					throw new RuntimeError("Not enough numbers on stack. Invalid formula.");
-				}
-				$stack[] = -$a;
-				break;
-			default:
-				$stack[] = $token;
-				break;
-			}
-		}
-		return array_pop($stack);
-	}
-	
-	public static function calc($expr) {
-		return self::calc_rpn(self::shunting_yard($expr));
-	}
-}
\ No newline at end of file
-- 
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