Fix missing backslash escaping (#43)

Author: KarimGeiger

src/Builder.php

@@ -122,7 +122,7 @@ class Builder extends TestMethodProvider
             'allowed' => self::METHOD_TYPES_ALLOWED_FOR_CHARACTERS
         ],
         'backslash' => [
-            'add' => '\\',
+            'add' => '\\\\',
             'type' => self::METHOD_TYPE_CHARACTER,
             'allowed' => self::METHOD_TYPES_ALLOWED_FOR_CHARACTERS
         ],

src/Language/Helpers/Matcher.php

@@ -30,6 +30,7 @@ class Matcher
         'all' => ['class' => Methods\SimpleMethod::class, 'method' => 'all'],
         'anything' => ['class' => Methods\SimpleMethod::class, 'method' => 'any'],
         'tab' => ['class' => Methods\SimpleMethod::class, 'method' => 'tab'],
+        'backslash' => ['class' => Methods\SimpleMethod::class, 'method' => 'backslash'],
         'unicode' => ['class' => Methods\SimpleMethod::class, 'method' => 'unicode'],
         'digit' => ['class' => Methods\SimpleMethod::class, 'method' => 'digit'],
         'not digit' => ['class' => Methods\SimpleMethod::class, 'method' => 'notDigit'],

tests/LanguageInterpreterTest.php

@@ -53,6 +53,11 @@ public function testParser()
 
         $srl = new SRL('starts with not one of "!@#/"');
         $this->assertEquals('/^[^!@#\/]/', $srl->get());
+
+        $srl = new SRL('backslash');
+        $this->assertEquals('/\\\\/', $srl->get());
+        $this->assertTrue($srl->isMatching('\\'));
+        $this->assertFalse($srl->isMatching('/'));
     }
 
     public function testEmail()