Implemented support for PHP's ** pow expression.

After a dependency update on pdepend this should fix phpmd/phpmd#400

src/main/php/PDepend/Source/Language/PHP/PHPParserVersion56.php

@@ -140,6 +140,7 @@ protected function parseStaticValueVersionSpecific(ASTValue $value)
                 case Tokens::T_MUL:
                 case Tokens::T_DIV:
                 case Tokens::T_MOD:
+                case Tokens::T_POW:
                 case Tokens::T_IS_EQUAL: // TODO: Implement compare expressions
                 case Tokens::T_IS_NOT_EQUAL:
                 case Tokens::T_IS_IDENTICAL:
@@ -247,4 +248,48 @@ protected function parseStaticValueVersionSpecific(ASTValue $value)
 
         return $value;
     }
+
+    /**
+     * This method will be called when the base parser cannot handle an expression
+     * in the base version. In this method you can implement version specific
+     * expressions.
+     *
+     * @return \PDepend\Source\AST\ASTNode
+     * @throws \PDepend\Source\Parser\UnexpectedTokenException
+     * @since 2.2
+     */
+    protected function parseOptionalExpressionForVersion()
+    {
+        if ($expression = $this->parseExpressionVersion56()) {
+            return $expression;
+        }
+        return parent::parseOptionalExpressionForVersion();
+    }
+
+    /**
+     * In this method we implement parsing of PHP 5.6 specific expressions.
+     *
+     * @return \PDepend\Source\AST\ASTNode
+     * @since 2.3
+     */
+    protected function parseExpressionVersion56()
+    {
+        $this->consumeComments();
+        $nextTokenType = $this->tokenizer->peek();
+
+        switch ($nextTokenType) {
+            case Tokens::T_POW:
+                $token = $this->consumeToken($nextTokenType);
+
+                $expr = $this->builder->buildAstExpression($token->image);
+                $expr->configureLinesAndColumns(
+                    $token->startLine,
+                    $token->endLine,
+                    $token->startColumn,
+                    $token->endColumn
+                );
+
+                return $expr;
+        }
+    }
 }

src/main/php/PDepend/Source/Language/PHP/PHPTokenizerInternal.php

@@ -159,6 +159,13 @@
     define('T_COALESCE', 42014);
 }
 
+/**
+ * Define PHP 7's '**' token constant
+ */
+if (!defined('T_POW')) {
+    define('T_POW', 42015);
+}
+
 /**
  * This tokenizer uses the internal {@link token_get_all()} function as token stream
  * generator.
@@ -183,6 +190,7 @@ class PHPTokenizerInternal implements Tokenizer
         T_FOR                       =>  Tokens::T_FOR,
         T_INC                       =>  Tokens::T_INC,
         T_NEW                       =>  Tokens::T_NEW,
+        T_POW                       =>  Tokens::T_POW,
         T_TRY                       =>  Tokens::T_TRY,
         T_USE                       =>  Tokens::T_USE,
         T_VAR                       =>  Tokens::T_VAR,
@@ -486,6 +494,13 @@ class PHPTokenizerInternal implements Tokenizer
                 'image' => '??',
             )
         ),
+
+        Tokens::T_MUL => array(
+            Tokens::T_MUL => array(
+                'type'  => Tokens::T_POW,
+                'image' => '**',
+            )
+        ),
     );
 
     /**

src/main/php/PDepend/Source/Tokenizer/Tokens.php

@@ -867,6 +867,11 @@ interface Tokens
      */
     const T_COALESCE = 163;
 
+    /**
+     * Token that represents the '**' null coalescing operator
+     */
+    const T_POW = 164;
+
     /**
      * Marks any content not between php tags.
      */

src/main/php/PDepend/Util/Cache/CacheDriver.php

@@ -55,7 +55,7 @@ interface CacheDriver
     /**
      * The current cache version.
      */
-    const VERSION = '@version:60fe3ebc147c387ccab6869746c14cea:@';
+    const VERSION = '@version:9d43b6160799565e7b28225144228960:@';
 
     /**
      * Sets the type for the next <em>store()</em> or <em>restore()</em> method

src/test/php/PDepend/Source/Language/PHP/PHPParserGenericVersion56Test.php

@@ -205,4 +205,30 @@ public function testComplexExpressionInFieldDeclaration()
 
         $this->assertNotNull($node);
     }
+
+    /**
+     * testPowExpressionInMethodBody
+     *
+     * @return void
+     */
+    public function testPowExpressionInMethodBody()
+    {
+        $node = $this->getFirstClassForTestCase()
+            ->getFirstChildOfType('PDepend\\Source\\AST\\ASTReturnStatement');
+
+        $this->assertSame('**', $node->getChild(0)->getChild(1)->getImage());
+    }
+
+    /**
+     * testPowExpressionInFieldDeclaration
+     *
+     * @return void
+     */
+    public function testPowExpressionInFieldDeclaration()
+    {
+        $node = $this->getFirstClassForTestCase()
+            ->getFirstChildOfType('PDepend\\Source\\AST\\ASTFieldDeclaration');
+
+        $this->assertNotNull($node);
+    }
 }

src/test/php/PDepend/Source/Language/PHP/PHPParserVersion56Test.php

@@ -99,6 +99,32 @@ public function testComplexExpressionInFieldDeclaration()
         $this->assertNotNull($node);
     }
 
+    /**
+     * testPowExpressionInMethodBody
+     *
+     * @return void
+     */
+    public function testPowExpressionInMethodBody()
+    {
+        $node = $this->getFirstClassForTestCase()
+            ->getFirstChildOfType('PDepend\\Source\\AST\\ASTReturnStatement');
+
+        $this->assertSame('**', $node->getChild(0)->getChild(1)->getImage());
+    }
+
+    /**
+     * testPowExpressionInFieldDeclaration
+     *
+     * @return void
+     */
+    public function testPowExpressionInFieldDeclaration()
+    {
+        $node = $this->getFirstClassForTestCase()
+            ->getFirstChildOfType('PDepend\\Source\\AST\\ASTFieldDeclaration');
+
+        $this->assertNotNull($node);
+    }
+
     /**
      * @param \PDepend\Source\Tokenizer\Tokenizer $tokenizer
      * @param \PDepend\Source\Builder\Builder $builder

src/test/resources/files/Source/Language/PHP/PHPParserGenericVersion56/testPowExpressionInFieldDeclaration.php

@@ -0,0 +1,5 @@
+<?php
+class testPowExpressionInFieldDeclaration_class
+{
+    public $x = 42**23;
+}

src/test/resources/files/Source/Language/PHP/PHPParserGenericVersion56/testPowExpressionInMethodBody.php

@@ -0,0 +1,8 @@
+<?php
+class testPowOperatorIsHandled_class
+{
+    public function testPowOperatorIsHandled()
+    {
+        return 42 ** 23;
+    }
+}

src/test/resources/files/Source/Language/PHP/PHPParserVersion56/testPowExpressionInFieldDeclaration.php

@@ -0,0 +1,5 @@
+<?php
+class testPowExpressionInFieldDeclaration_class
+{
+    public $x = 42**23;
+}

src/test/resources/files/Source/Language/PHP/PHPParserVersion56/testPowExpressionInMethodBody.php

@@ -0,0 +1,8 @@
+<?php
+class testPowOperatorIsHandled_class
+{
+    public function testPowOperatorIsHandled()
+    {
+        return 42 ** 23;
+    }
+}