Support for unary positive expressions (#85)

* Support for unary positive operator

3 files changed, 41 insertions, 23 deletions

diff --git a/src/NXP/Classes/Tokenizer.php b/src/NXP/Classes/Tokenizer.php
index bb6fa15..f8056c3 100644
--- a/src/NXP/Classes/Tokenizer.php
+++ b/src/NXP/Classes/Tokenizer.php
@@ -150,11 +150,11 @@ class Tokenizer
                     $this->tokens[] = new Token(Token::ParamSeparator, '');
                     break;
                 default:
-                    // special case for unary minus
-                    if ($ch == '-') {
+                    // special case for unary operations
+                    if ($ch == '-' || $ch == '+') {
                         if ($this->allowNegative) {
                             $this->allowNegative = false;
-                            $this->tokens[] = new Token(Token::Operator, '`');
+                            $this->tokens[] = new Token(Token::Operator, $ch == '-' ? 'uNeg' : 'uPos');
                             continue 2;
                         }
                         // could be in exponent, in which case negative should be added to the numberBuffer
diff --git a/src/NXP/MathExecutor.php b/src/NXP/MathExecutor.php
index b8e8a65..a774561 100644
--- a/src/NXP/MathExecutor.php
+++ b/src/NXP/MathExecutor.php
@@ -16,8 +16,8 @@ use NXP\Classes\CustomFunction;
 use NXP\Classes\Operator;
 use NXP\Classes\Tokenizer;
 use NXP\Exception\DivisionByZeroException;
-use NXP\Exception\UnknownVariableException;
 use NXP\Exception\MathExecutorException;
+use NXP\Exception\UnknownVariableException;
 use ReflectionException;
 
 /**
@@ -85,35 +85,42 @@ class MathExecutor
     protected function defaultOperators() : array
     {
         return [
-            '+' => [
+            '+'    => [
                 function ($a, $b) {
                     return $a + $b;
                 },
                 170,
                 false
             ],
-            '-' => [
+            '-'    => [
                 function ($a, $b) {
                     return $a - $b;
                 },
                 170,
                 false
             ],
-            '`' => [ // unary minus token
-                function ($a) {
-                    return 0 - $a;
-                },
-                200,
-                false
+            'uPos' => [ // unary positive token
+                        function ($a) {
+                            return $a;
+                        },
+                        200,
+                        false
+            ],
+            'uNeg' => [ // unary minus token
+                        function ($a) {
+                            return 0 - $a;
+                        },
+                        200,
+                        false
             ],
-            '*' => [
+            '*'    => [
                 function ($a, $b) {
                     return $a * $b;
                 },
                 180,
                 false
             ],
-            '/' => [
+            '/'    => [
                 function ($a, $b) {
                     if ($b == 0) {
                         throw new DivisionByZeroException();
@@ -123,28 +130,28 @@ class MathExecutor
                 180,
                 false
             ],
-            '^' => [
+            '^'    => [
                 function ($a, $b) {
                     return pow($a, $b);
                 },
                 220,
                 true
             ],
-            '&&' => [
+            '&&'   => [
                 function ($a, $b) {
                     return $a && $b;
                 },
                 100,
                 false
             ],
-            '||' => [
+            '||'   => [
                 function ($a, $b) {
                     return $a || $b;
                 },
                 90,
                 false
             ],
-            '==' => [
+            '=='   => [
                 function ($a, $b) {
                     if (is_string($a) || is_string($b)) {
                         return strcmp($a, $b) == 0;
@@ -155,7 +162,7 @@ class MathExecutor
                 140,
                 false
             ],
-            '!=' => [
+            '!='   => [
                 function ($a, $b) {
                     if (is_string($a) || is_string($b)) {
                         return strcmp($a, $b) != 0;
@@ -166,28 +173,28 @@ class MathExecutor
                 140,
                 false
             ],
-            '>=' => [
+            '>='   => [
                 function ($a, $b) {
                     return $a >= $b;
                 },
                 150,
                 false
             ],
-            '>' => [
+            '>'    => [
                 function ($a, $b) {
                     return $a > $b;
                 },
                 150,
                 false
             ],
-            '<=' => [
+            '<='   => [
                 function ($a, $b) {
                     return $a <= $b;
                 },
                 150,
                 false
             ],
-            '<' => [
+            '<'    => [
                 function ($a, $b) {
                     return $a < $b;
                 },
diff --git a/tests/MathTest.php b/tests/MathTest.php
index a843db5..dee3f39 100644
--- a/tests/MathTest.php
+++ b/tests/MathTest.php
@@ -252,6 +252,17 @@ class MathTest extends TestCase
         $this->assertEquals(0, $calculator->execute('10 / 0'));
     }
 
+    public function testUnaryOperators()
+    {
+        $calculator = new MathExecutor();
+        $this->assertEquals(5, $calculator->execute('+5'));
+        $this->assertEquals(5, $calculator->execute('+(3+2)'));
+        $this->assertEquals(-5, $calculator->execute('-5'));
+        $this->assertEquals(5, $calculator->execute('-(-5)'));
+        $this->assertEquals(-5, $calculator->execute('+(-5)'));
+        $this->assertEquals(-5, $calculator->execute('-(3+2)'));
+    }
+
     public function testZeroDivisionException()
     {
         $calculator = new MathExecutor();