Merge pull request #40 from KVTaniguchi/refactorValidationRule

apply rules with map and filter

Author: jpotts18

Validator/ValidationRule.swift

@@ -21,11 +21,7 @@ public class ValidationRule {
     }
 
     public func validateField() -> ValidationError? {
-        for rule in rules {
-            if !rule.validate(textField.text) {
-                return ValidationError(textField: self.textField, errorLabel:self.errorLabel, error: rule.errorMessage())
-            }
-        }
-        return nil
+        return rules.filter{ !$0.validate(self.textField.text) }
+                    .map{ rule -> ValidationError in return ValidationError(textField: self.textField, errorLabel:self.errorLabel, error: rule.errorMessage()) }.first
     }
 }