diff --git a/.travis.yml b/.travis.yml
index 2f3e9ab..b7d1bac 100755
--- a/.travis.yml
+++ b/.travis.yml
@@ -37,7 +37,7 @@ before_script:
 
 script:
   - sh -c "if [ '$DEFAULT' = '1' ]; then phpunit --stderr; fi"
-  - sh -c "if [ '$PHPCS' = '1' ]; then vendor/bin/phpcs -p --extensions=php --standard=PSR2 ./src; fi"
+  - sh -c "if [ '$PHPCS' = '1' ]; then vendor/bin/phpcs -p --extensions=php --standard=ruleset.xml ./src; fi"
   - sh -c "if [ '$COVERALLS' = '1' ]; then phpunit --stderr --coverage-clover build/logs/clover.xml; fi"
 
 after_script:
diff --git a/README.md b/README.md
index bf1ba3b..3dbbb60 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,5 @@
+[![Build Status](https://travis-ci.org/sizuhiko/hexpress.svg?branch=master)](https://travis-ci.org/sizuhiko/hexpress) [![Coverage Status](https://coveralls.io/repos/sizuhiko/hexpress/badge.svg?branch=master&service=github)](https://coveralls.io/github/sizuhiko/hexpress?branch=master) [![Latest Stable Version](https://poser.pugx.org/sizuhiko/hexpress/v/stable)](https://packagist.org/packages/sizuhiko/hexpress) [![Total Downloads](https://poser.pugx.org/sizuhiko/hexpress/downloads)](https://packagist.org/packages/sizuhiko/hexpress) [![Latest Unstable Version](https://poser.pugx.org/sizuhiko/hexpress/v/unstable)](https://packagist.org/packages/sizuhiko/hexpress) [![License](https://poser.pugx.org/sizuhiko/hexpress/license)](https://packagist.org/packages/sizuhiko/hexpress)
+
 # hexpress
 hexpress is a PHP library that human way to define regular expressions
 
diff --git a/ruleset.xml b/ruleset.xml
new file mode 100755
index 0000000..208dd99
--- /dev/null
+++ b/ruleset.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+<ruleset name="My Standards">
+    <description>My Coding Standards enforcement rule set for PHP_CodeSniffer</description>
+    <rule ref="PSR2">
+        <exclude name="PSR1.Classes.ClassDeclaration.MultipleClasses" />
+        <exclude name="Squiz.Functions.MultiLineFunctionDeclaration.ContentAfterBrace" />
+        <exclude name="Squiz.WhiteSpace.ScopeClosingBrace.ContentBefore" />
+        <exclude name="Generic.Formatting.DisallowMultipleStatements.SameLine" />
+    </rule>
+    <rule ref="Generic.Files.LineLength">
+        <properties>
+            <property name="lineLimit" value="140"/>
+            <property name="absoluteLineLimit" value="160"/>
+        </properties>
+     </rule>
+</ruleset>
diff --git a/src/Hexpress.php b/src/Hexpress.php
index 06928d5..a8ee0ef 100644
--- a/src/Hexpress.php
+++ b/src/Hexpress.php
@@ -219,29 +219,24 @@ private function add($hex)
         return $this;
     }
 
-    private function add_value($hex, $value)
+    private function addValue($hex, $value)
     {
         $this->add(new $hex(is_callable($value) ? new self($value) : $value));
 
         return $this;
     }
 
-    private function add_nested($hex, $value)
+    private function addNested($hex, $value)
     {
         $this->add(new $hex($value));
 
         return $this;
     }
 
-    private function add_values($hex, $value, $option)
+    private function addValues($hex, $value, $option)
     {
         $this->add(new $hex(is_callable($value) ? new self($value) : $value, $option));
 
         return $this;
     }
-
-    private function pop_value()
-    {
-        return array_pop($this->expressions);
-    }
 }
diff --git a/src/Hexpress/Limit.php b/src/Hexpress/Limit.php
index 476cce3..262903f 100644
--- a/src/Hexpress/Limit.php
+++ b/src/Hexpress/Limit.php
@@ -6,7 +6,7 @@ trait Limit
 {
     public function limit($value, $min, $max = 0)
     {
-        return $this->add_values(LimitValue::class, $value, [$min, $max]);
+        return $this->addValues(LimitValue::class, $value, [$min, $max]);
     }
 }
 
diff --git a/src/Hexpress/Many.php b/src/Hexpress/Many.php
index 03931a0..5e4e7dd 100644
--- a/src/Hexpress/Many.php
+++ b/src/Hexpress/Many.php
@@ -9,7 +9,7 @@ public function many($value = null, $minimum = 1)
         if($minimum > 1) {
             return $this->limit($value, $minimum);
         }
-        return $this->add_values(ManyValue::class, $value, $minimum);
+        return $this->addValues(ManyValue::class, $value, $minimum);
     }
 }
 
diff --git a/src/Hexpress/Nested.php b/src/Hexpress/Nested.php
index b5f3fbf..7fba8cc 100644
--- a/src/Hexpress/Nested.php
+++ b/src/Hexpress/Nested.php
@@ -13,7 +13,7 @@ public function delimiter()
 
     public function hexpression()
     {
-        return $this->joinable() ? $this->join_hexpression() : $this->hexpression;
+        return $this->joinable() ? $this->joinHexpression() : $this->hexpression;
     }
 
     public function __toString()
@@ -21,7 +21,7 @@ public function __toString()
         return $this->wrapping($this->hexpression());
     }
 
-    private function join_hexpression()
+    private function joinHexpression()
     {
         return implode($this->delimiter(), $this->hexpression);
     }
diff --git a/src/Hexpress/Nested/Find.php b/src/Hexpress/Nested/Find.php
index d4d4dbe..0019f20 100644
--- a/src/Hexpress/Nested/Find.php
+++ b/src/Hexpress/Nested/Find.php
@@ -11,7 +11,7 @@ public function find($value = null, $named = false)
     {
         $param = compact('value', 'named');
 
-        return is_callable($value) ? $this->add_nested(FindValue::class, $param) : $this->add_value(FindValue::class, $param);
+        return is_callable($value) ? $this->addNested(FindValue::class, $param) : $this->addValue(FindValue::class, $param);
     }
     public function capture($value = null)
     {
diff --git a/src/Hexpress/Nested/Matching.php b/src/Hexpress/Nested/Matching.php
index ed2fbcf..39b29c8 100644
--- a/src/Hexpress/Nested/Matching.php
+++ b/src/Hexpress/Nested/Matching.php
@@ -9,7 +9,7 @@ trait Matching
 {
     public function matching($callback)
     {
-        return $this->add_nested(MatchingValue::class, $callback);
+        return $this->addNested(MatchingValue::class, $callback);
     }
     public function like($callback)
     {
@@ -32,7 +32,7 @@ public function __construct($callback)
         $this->close = ']';
     }
 
-    public function join_hexpression()
+    public function joinHexpression()
     {
         return implode('', array_map(function ($value) {
             return $this->escape($value);
diff --git a/src/Hexpress/One.php b/src/Hexpress/One.php
index 789ec13..bdce982 100644
--- a/src/Hexpress/One.php
+++ b/src/Hexpress/One.php
@@ -8,7 +8,7 @@ trait One
 {
     public function one($value = null)
     {
-        return $this->add_value(OneValue::class, $value);
+        return $this->addValue(OneValue::class, $value);
     }
     public function maybe($value = null)
     {
diff --git a/src/Hexpress/Value/Ending.php b/src/Hexpress/Value/Ending.php
index 9915cfa..2e44124 100644
--- a/src/Hexpress/Value/Ending.php
+++ b/src/Hexpress/Value/Ending.php
@@ -8,7 +8,7 @@ trait Ending
 {
     public function ending($value = null)
     {
-        return $this->add_value(EndingValue::class, $value);
+        return $this->addValue(EndingValue::class, $value);
     }
     public function end($value = null)
     {
diff --git a/src/Hexpress/Value/Except.php b/src/Hexpress/Value/Except.php
index 75a03e0..54b7640 100644
--- a/src/Hexpress/Value/Except.php
+++ b/src/Hexpress/Value/Except.php
@@ -8,7 +8,7 @@ trait Except
 {
     public function except($value)
     {
-        return $this->add_value(ExceptValue::class, $value);
+        return $this->addValue(ExceptValue::class, $value);
     }
     public function excluding($value)
     {
diff --git a/src/Hexpress/Value/Starting.php b/src/Hexpress/Value/Starting.php
index c7fa53b..53752c8 100644
--- a/src/Hexpress/Value/Starting.php
+++ b/src/Hexpress/Value/Starting.php
@@ -8,7 +8,7 @@ trait Starting
 {
     public function starting($value = null)
     {
-        return $this->add_value(StartingValue::class, $value);
+        return $this->addValue(StartingValue::class, $value);
     }
     public function begins($value)
     {
diff --git a/src/Hexpress/Value/With.php b/src/Hexpress/Value/With.php
index 81909b5..9df833a 100644
--- a/src/Hexpress/Value/With.php
+++ b/src/Hexpress/Value/With.php
@@ -8,7 +8,7 @@ trait With
 {
     public function with($value)
     {
-        return $this->add_value(WithValue::class, $value);
+        return $this->addValue(WithValue::class, $value);
     }
     public function has($value)
     {
diff --git a/src/Hexpress/Values/Either.php b/src/Hexpress/Values/Either.php
index 54acb7e..a6c3447 100644
--- a/src/Hexpress/Values/Either.php
+++ b/src/Hexpress/Values/Either.php
@@ -9,7 +9,7 @@ trait Either
 {
     public function either($values)
     {
-        return $this->add_value(EitherValue::class, $values);
+        return $this->addValue(EitherValue::class, $values);
     }
     public function anyOf($values)
     {
diff --git a/src/Hexpress/Values/Range.php b/src/Hexpress/Values/Range.php
index 318d3c6..4a82cc2 100644
--- a/src/Hexpress/Values/Range.php
+++ b/src/Hexpress/Values/Range.php
@@ -18,21 +18,21 @@ public function lower($value = false)
     {
         $value = empty($value) ? range('a', 'z') : $value;
 
-        return $this->add_value(RangeValue::class, $value);
+        return $this->addValue(RangeValue::class, $value);
     }
 
     public function upper($value = false)
     {
         $value = empty($value) ? range('A', 'Z') : $value;
 
-        return $this->add_value(RangeValue::class, $value);
+        return $this->addValue(RangeValue::class, $value);
     }
 
     public function number($value = false)
     {
         $value = empty($value) ? range('0', '9') : $value;
 
-        return $this->add_value(RangeValue::class, $value);
+        return $this->addValue(RangeValue::class, $value);
     }
 }