small changes

README.md

@@ -7,6 +7,10 @@ like from JSON string, PHP files, etc.
 These expressions are used to configure the expression parser engine which
 runs a value through the rules defined in the array expression to return a result.
 
+## Installation
+
+
+
 ## Usage
 
 ```php
@@ -38,14 +42,21 @@ foreach ($values as $value) {
 
 ### Operators
 
+#### Summary
+
+Following operators are available:
+
 Operator | Name | Definition | Example
 -------- | ---- | ---------- | -------
 AND | AND operator  | `['and', <expression1>, ..., <expressionN>]` | `['and', ['compare', 'name', 'test'], ['compare', 'age', '>', 2]]`  
 OR | OR operator  | `['or', <expression1>, ..., <expressionN>]` | `['or', ['compare', 'name', 'test'], ['compare', 'age', '>', 2]]`
 XOR | XOR operator (exclusive OR)  | `['xor', <expression1>, ..., <expressionN>]` | `['xor', ['compare', 'name', 'test'], ['compare', 'age', '>', 2]]`
+NOT | NOT operator (inverts check)  | `['not', <expression>]` | `['not', ['compare', 'name', 'test']]`
 COMPARE | Comparison operator | `['compare', 'value']`,<br> `['compare', 'name', 'value']`,<br> `['compare, 'name', '=', 'value']`,<br>`['compare, 'name', '>=', 0, 'default' => 0]` | `['compare', 'age', '>', 2]`
 REGEX | Regex operator | `['regex', '/pattern/']`, `['regex', 'name', '/pattern/']` | `['regex', 'name', '/snow/']`
 
+Custom operators can be created and added to the evaluator as needed.
+
 
 ## Tests
 

src/Evaluator.php

@@ -66,13 +66,9 @@ public static function create($expressionParser = null)
      */
     public function run(array $expression, $value)
     {
-        $valueParser = $this->determineValueParser($value);
-
-        if ($this->expressionParser === null) {
-            $this->expressionParser = new DefaultExpressionParser();
-        }
-
-        return $this->expressionParser->parse($expression)->evaluate($valueParser);
+        return $this->getExpressionParser()
+            ->parse($expression)
+            ->evaluate($this->determineValueParser($value));
     }
 
     /**
@@ -93,7 +89,9 @@ protected function determineValueParser($value)
 
             $valueParser->setRaw($value);
             return $valueParser;
-        } elseif (is_object($value)) {
+        }
+
+        if (is_object($value)) {
             if (!($this->valueParser instanceof ObjectValueParser)) {
                 $valueParser = $this->valueParser = new ObjectValueParser();
             }
@@ -109,4 +107,18 @@ protected function determineValueParser($value)
 
         return $valueParser;
     }
+
+    /**
+     * Returns expression parser.
+     *
+     * @return ExpressionParser
+     */
+    public function getExpressionParser()
+    {
+        if ($this->expressionParser === null) {
+            $this->expressionParser = new DefaultExpressionParser();
+        }
+
+        return $this->expressionParser;
+    }
 }

tests/EvaluateTest.php

@@ -15,14 +15,14 @@ class EvaluateTest extends TestCase
     public function testCreateInitialInstance()
     {
         $i = $this->createInstance();
-        $this->assertEquals(null, $i->getExpressionParser());
+        $this->assertEquals(null, $i->getCurrentExpressionParser());
     }
 
     public function testParserGetsPassedInConstructor()
     {
         $parser = new ExpressionParser();
         $i = $this->createInstance($parser);
-        $this->assertEquals($parser, $i->getExpressionParser());
+        $this->assertEquals($parser, $i->getCurrentExpressionParser());
     }
 
     public function testEvaluatorRun()

tests/Spies/EvaluatorSpy.php

@@ -11,7 +11,7 @@
 
 class EvaluatorSpy extends Evaluator
 {
-    public function getExpressionParser()
+    public function getCurrentExpressionParser()
     {
         return $this->expressionParser;
     }