MDL-9643 mathslib.php library, unit tests, removed e and pi constants

lib/evalmath/evalmath.class.php

@@ -91,7 +91,7 @@ class EvalMath {
     var $suppress_errors = false;
     var $last_error = null;
 
-    var $v = array('e'=>2.71,'pi'=>3.14); // variables (and constants)
+    var $v = array(); // variables (and constants)
     var $f = array(); // user-defined functions
     var $vb = array('e', 'pi'); // constants
     var $fb = array(  // built-in functions
@@ -104,9 +104,6 @@ class EvalMath {
         'sum'=>array(-1), 'pi'=>array(0), 'power'=>array(2), 'round'=>array(2,1), 'average'=>array(-1));
 
     function EvalMath() {
-        // make the variables a little more accurate
-        $this->v['pi'] = pi();
-        $this->v['e'] = exp(1);
     }
 
     function e($expr) {

lib/evalmath/readme_moodle.txt

@@ -3,6 +3,7 @@ Description of MathEval library import into Moodle
 Our changes:
 * implicit multiplication not allowed
 * new custom calc emulation functions
+* removed e and pi constants - not use din calc
 
 To see all changes diff against version 1.1
 

lib/mathslib.php

@@ -0,0 +1,57 @@
+<?php
+
+require_once $CFG->dirroot.'/lib/evalmath/evalmath.class.php';
+
+class calc_formula {
+
+    var $em;
+    var $nfx = false;
+    var $error = false;
+
+    function calc_formula($formula, $params=false) {
+        $this->em = new EvalMath();
+        $this->em->suppress_errors = true;
+        if (strpos($formula, '=') !== 0) {
+            $this->error = "missing '='";
+            return;
+        }
+        $formula = substr($formula, 1);
+        if (strpos($formula, '=') !== false) {
+            $this->error = "too many '='";
+            return;
+        }
+        $this->nfx = $this->em->nfx($formula);
+        if ($this->nfx == false) {
+            $this->error = $this->em->last_error;
+            return;
+        }
+        if ($params != false) {
+            $this->em->v = $params;
+        }
+    }
+
+    function set_params($params) {
+        $this->em->v = $params;
+    }
+
+    function evaluate() {
+        if ($this->nfx == false) {
+            return false;
+        }
+        $res = $this->em->pfx($this->nfx);
+        if ($res === false) {
+            $this->error = $this->em->last_error;
+            return false;
+        } else {
+            $this->error = false;
+            return $res;
+        }
+
+    }
+
+    function get_error() {
+        return $this->error;
+    }
+}
+
+?>

lib/simpletest/testmathslib.php

@@ -0,0 +1,56 @@
+<?php
+
+/* $Id$ */
+
+if (!defined('MOODLE_INTERNAL')) {
+    die('Direct access to this script is forbidden.');    ///  It must be included from a Moodle page
+}
+
+global $CFG;
+require_once($CFG->libdir . '/simpletestlib.php');
+require_once($CFG->libdir . '/mathslib.php');
+
+class mathsslib_test extends UnitTestCase {
+
+    /**
+     * Tests the basic formula execition
+     */
+    function test__basic() {
+        $calc = new calc_formula('=1+2');
+        $res = $calc->evaluate();
+        $this->assertEqual($res, 3, '3+1 is: %s');
+    }
+
+    /**
+     * Tests the formula params
+     */
+    function test__params() {
+        $calc = new calc_formula('=a+b+c', array('a'=>10,'b'=>20,'c'=>30));
+        $res = $calc->evaluate();
+        $this->assertEqual($res, 60, '10+20+30 is: %s');
+    }
+
+    /**
+     * Tests the formula params
+     */
+    function test__calc_function() {
+        $calc = new calc_formula('=sum(a,b,c)', array('a'=>10,'b'=>20,'c'=>30));
+        $res = $calc->evaluate();
+        $this->assertEqual($res, 60, 'sum(a,b,c) is: %s');
+    }
+
+    /**
+     * Tests the formula changed params
+     */
+    function test__changing_params() {
+        $calc = new calc_formula('=a+b+c', array('a'=>10,'b'=>20,'c'=>30));
+        $res = $calc->evaluate();
+        $this->assertEqual($res, 60, '10+20+30 is: %s');
+        $calc->set_params(array('a'=>1,'b'=>2,'c'=>3));
+        $res = $calc->evaluate();
+        $this->assertEqual($res, 6, '1+2+3 is: %s');
+    }
+
+}
+
+?>