Add \ and ** operators to the parser

Use \ for integer division regardless of the scale, and ** for `BC::pow()`.
danhunsaker · Feb 24, 2016 · 8bdb0ef · 8bdb0ef
1 parent cbf5176
commit 8bdb0ef
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Showing 5 changed files with 21 additions and 9 deletions.
diff --git a/README.md b/README.md
@@ -64,9 +64,11 @@ your expressions:
 
 - `BC::add(a, b)`     => `'a + b'`
 - `BC::div(a, b)`     => `'a / b'`
+- `BC::div(a, b, 0)`  => `'a \ b'`
 - `BC::mod(a, b)`     => `'a % b'`
 - `BC::modfrac(a, b)` => `'a %% b'`
 - `BC::mul(a, b)`     => `'a * b'`
+- `BC::pow(a, b)`     => `'a ** b'`
 - `BC::powfrac(a, b)` => `'a ^ b'`
 - `BC::sub(a, b)`     => `'a - b'`
 

diff --git a/features/parse.feature b/features/parse.feature
@@ -21,12 +21,16 @@ Feature: Parse Method Implementation
       | 18    | 1 * 5          | 5.000000000000000000   |
       | 0     | 1 / 5          | 0                      |
       | 18    | 1 / 5          | 0.200000000000000000   |
+      | 0     | 1 \ 5          | 0                      |
+      | 18    | 1 \ 5          | 0.000000000000000000   |
       | 0     | 1 % 5          | 1                      |
       | 18    | 1 % 5          | 1.000000000000000000   |
       | 0     | 5.5 %% 1       | 0                      |
       | 18    | 5.5 %% 1       | 0.500000000000000000   |
-      | 0     | 1 ^ .5         | 1                      |
-      | 18    | 1 ^ .5         | 1.000000000000000000   |
+      | 0     | 4 ** .5        | 1                      |
+      | 18    | 4 ** .5        | 1.000000000000000000   |
+      | 0     | 4 ^ .5         | 2                      |
+      | 18    | 4 ^ .5         | 2.000000000000000000   |
       | 0     | 1 = 5          | false                  |
       | 18    | 1 = 5          | false                  |
       | 0     | 1 == 5         | false                  |

diff --git a/spec/BCSpec.php b/spec/BCSpec.php
@@ -46,9 +46,10 @@ public function it_should_have_extended_functionality()
 
     public function it_should_have_utility_functions()
     {
-        $this->scale(18);
+        $this::scale(18);
         $this::parse('1 + 5')->shouldBeLike('6');
         $this::parse('1 - 5')->shouldBeLike('-4');
+        $this::parse('5 \ 4')->shouldBeLike('1');
         $this::parse('5 / 4')->shouldBeLike('1.25');
         $this::parse('1 + 1.25')->shouldBeLike('2.25');
         $this::parse('5 / 4 + 1')->shouldBeLike('2.25');
@@ -57,6 +58,7 @@ public function it_should_have_utility_functions()
         $this::parse('1 + -5 / 4')->shouldBeLike('-0.25');
         $this::parse('1 - +5 / 4')->shouldBeLike('-0.25');
         $this::parse('(1 + 5) / 4')->shouldBeLike('1.5');
+        $this::parse('(1 + 5) \ 4')->shouldBeLike('1');
         $this::parse('(1 + 5) / 4', null, 0)->shouldBeLike('1');
         $this::parse('({a} + {b}) / {c}', ['a' => 1, 'b' => 5, 'c' => 4])->shouldBeLike('1.5');
         $this::parse('({a} + {b}) / {c}', ['a' => 1, 'b' => 5, 'c' => 4], 0)->shouldBeLike('1');

diff --git a/src/BC.php b/src/BC.php
@@ -217,11 +217,11 @@ public static function parse($formula, $values = [], $scale = null)
         $formula = preg_replace("/\{[^{}]+\}/", '0', $formula);
 
         $operations = [];
-        if (strpos($formula, '^') !== false) {
-            $operations[] = '\^';
+        if (strpbrk($formula, '^*') !== false) {
+            $operations[] = '\^|\*\*';
         }
-        if (strpbrk($formula, '*/%') !== false) {
-            $operations[] = '\*|\/|\%{1,2}';
+        if (strpbrk($formula, '*/%\\') !== false) {
+            $operations[] = '\*|\\\\|\/|\%{1,2}';
         }
         if (strpbrk($formula, '+-') !== false) {
             $operations[] = '[\+\-]';
@@ -243,13 +243,15 @@ public static function parse($formula, $values = [], $scale = null)
                         case '-':  $result = static::sub($opTrio[1], $opTrio[3], $scale); break;
                         case '*':  $result = static::mul($opTrio[1], $opTrio[3], $scale); break;
                         case '/':  $result = static::div($opTrio[1], $opTrio[3], $scale); break;
+                        case '\\': $result = static::div($opTrio[1], $opTrio[3], 0); break;
                         case '%':  $result = static::mod($opTrio[1], $opTrio[3], $scale); break;
                         case '%%': $result = static::modfrac($opTrio[1], $opTrio[3], $scale); break;
+                        case '**': $result = static::pow($opTrio[1], $opTrio[3], $scale); break;
                         case '^':  $result = static::powfrac($opTrio[1], $opTrio[3], $scale); break;
                         case '==':
                         case '=':  $result = static::comp($opTrio[1], $opTrio[3], $scale) == 0; break;
-                        case '>':  $result = static::comp($opTrio[1], $opTrio[3], $scale) == 1; break;
-                        case '<':  $result = static::comp($opTrio[1], $opTrio[3], $scale) ==-1; break;
+                        case '>':  $result = static::comp($opTrio[1], $opTrio[3], $scale) >  0; break;
+                        case '<':  $result = static::comp($opTrio[1], $opTrio[3], $scale) <  0; break;
                         case '>=': $result = static::comp($opTrio[1], $opTrio[3], $scale) >= 0; break;
                         case '<=': $result = static::comp($opTrio[1], $opTrio[3], $scale) <= 0; break;
                         case '<>':

diff --git a/tests/BCTest.php b/tests/BCTest.php
@@ -183,6 +183,7 @@ public function testParse()
         BC::scale(18);
         $this->assertEquals('6', BC::parse('1 + 5'));
         $this->assertEquals('-4', BC::parse('1 - 5'));
+        $this->assertEquals('1', BC::parse('5 \ 4'));
         $this->assertEquals('1.25', BC::parse('5 / 4'));
         $this->assertEquals('2.25', BC::parse('1 + 1.25'));
         $this->assertEquals('2.25', BC::parse('5 / 4 + 1'));
@@ -191,6 +192,7 @@ public function testParse()
         $this->assertEquals('-0.25', BC::parse('1 + -5 / 4'));
         $this->assertEquals('-0.25', BC::parse('1 - +5 / 4'));
         $this->assertEquals('1.5', BC::parse('(1 + 5) / 4'));
+        $this->assertEquals('1', BC::parse('(1 + 5) \ 4'));
         $this->assertEquals('1', BC::parse('(1 + 5) / 4', null, 0));
         $this->assertEquals('1.5', BC::parse('({a} + {b}) / {c}', ['a' => 1, 'b' => 5, 'c' => 4]));
         $this->assertEquals('1', BC::parse('({a} + {b}) / {c}', ['a' => 1, 'b' => 5, 'c' => 4], 0));