MDL-27659 "have evalmath accept numbers expressed with scientific

notation"
jamiepratt · May 28, 2011 · 631c0ed · 631c0ed
1 parent ecf5200
commit 631c0ed
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Showing 2 changed files with 19 additions and 1 deletion.
diff --git a/lib/evalmath/evalmath.class.php b/lib/evalmath/evalmath.class.php
@@ -212,7 +212,7 @@ function nfx($expr) {
         while(1) { // 1 Infinite Loop ;)
             $op = substr($expr, $index, 1); // get the first character at the current index
             // find out if we're currently at the beginning of a number/variable/function/parenthesis/operand
-            $ex = preg_match('/^('.self::$namepat.'\(?|\d+(?:\.\d*)?|\.\d+|\()/', substr($expr, $index), $match);
+            $ex = preg_match('/^('.self::$namepat.'\(?|\d+(?:\.\d*)?(?:(e[+-]?)\d*)?|\.\d+|\()/', substr($expr, $index), $match);
             //===============
             if ($op == '-' and !$expecting_op) { // is it a negation instead of a minus?
                 $stack->push('_'); // put a negation on the stack

diff --git a/lib/simpletest/testmathslib.php b/lib/simpletest/testmathslib.php
@@ -194,6 +194,24 @@ public function test_rounding_function() {
 
     }
 
+    public function test_scientific_notation() {
+        $formula = new calc_formula('=10e10');
+        $this->assertWithinMargin($formula->evaluate(), 1e11, 1e11*1e-15);
+
+        $formula = new calc_formula('=10e-10');
+        $this->assertWithinMargin($formula->evaluate(), 1e-9, 1e11*1e-15);
+
+        $formula = new calc_formula('=10e+10');
+        $this->assertWithinMargin($formula->evaluate(), 1e11, 1e11*1e-15);
+
+        $formula = new calc_formula('=10e10*5');
+        $this->assertWithinMargin($formula->evaluate(), 5e11, 1e11*1e-15);
+
+        $formula = new calc_formula('=10e10^2');
+        $this->assertWithinMargin($formula->evaluate(), 1e22, 1e22*1e-15);
+
+    }
+
 }