Merge pull request #22 from lanwen/builder

add - factory methods for builder (with method to clone)

Author: lanwen

README.md

@@ -31,7 +31,7 @@ You can use *SNAPSHOT* dependency with adding to `pom.xml`:
 
 ##Examples
 ```java
-VerbalExpression testRegex = new VerbalExpression.Builder()
+VerbalExpression testRegex = VerbalExpression.regex()
 	           					 .startOfLine()
 	           					 .then("http")
 	           					 .maybe("s")
@@ -44,14 +44,13 @@ VerbalExpression testRegex = new VerbalExpression.Builder()
 // Create an example URL
 String url = "https://www.google.com";
 
-// Use VerbalExpression's testExact() method to test if the entire string matches
-// the regex
+// Use VerbalExpression's testExact() method to test if the entire string matches the regex
 testRegex.testExact(url); //True
 
 testRegex.toString(); // Outputs the regex used:
 					  // ^(http)(s)?(\:\/\/)(www\.)?([^\ ]*)$
 
-VerbalExpression testRegex = new VerbalExpression.Builder()
+VerbalExpression testRegex = VerbalExpression.regex()
                                  .startOfLine()
                                  .then("abc")
                                  .or("def")
@@ -64,6 +63,12 @@ testRegex.test(testString); //true
 testRegex.testExact(testString); //false
 ```
 
+Builder can be cloned:
+```java
+// Produce: (.*)$
+VerbalExpression regex = regex(regex().anything().addModifier('i')).endOfLine().build();
+```
+
 ## Other implementations  
 You can view all implementations on [VerbalExpressions.github.io](http://VerbalExpressions.github.io)
 - [Javascript](https://github.com/VerbalExpressions/JSVerbalExpressions)

src/main/java/ru/lanwen/verbalregex/VerbalExpression.java

@@ -12,24 +12,23 @@ public static class Builder {
         private StringBuilder prefixes = new StringBuilder();
         private StringBuilder source = new StringBuilder();
         private StringBuilder suffixes = new StringBuilder();
-        private Pattern pattern;
         private int modifiers = Pattern.MULTILINE;
 
         private String sanitize(final String pValue) {
         	return pValue.replaceAll("[\\W]", "\\\\$0");
         }
 
+        public VerbalExpression build() {
+            Pattern pattern = Pattern.compile(new StringBuilder(prefixes)
+                    .append(source).append(suffixes).toString(), modifiers);
+            return new VerbalExpression(pattern);
+        }
+
         public Builder add(String pValue) {
             this.source.append(pValue);
             return this;
         }
 
-        public VerbalExpression build() {
-            pattern = Pattern.compile(new StringBuilder(prefixes)
-                    .append(source).append(suffixes).toString(), modifiers);
-            return new VerbalExpression(this);
-        }
-
         public Builder startOfLine(boolean pEnable) {
             this.prefixes.append(pEnable ? "^" : "");
             return this;
@@ -254,8 +253,8 @@ public boolean test(final String pToTest) {
         return ret;
     }
 
-    private VerbalExpression(final Builder pBuilder) {
-        pattern = pBuilder.pattern;
+    private VerbalExpression(final Pattern pattern) {
+        this.pattern = pattern;
     }
 
     public String getText(String toTest) {
@@ -265,7 +264,22 @@ public String getText(String toTest) {
             result.append(m.group());
         }
         return result.toString();
-    }    
+    }
+
+    public static Builder regex(final Builder pBuilder) {
+        Builder builder = new Builder();
+
+        builder.prefixes = new StringBuilder(pBuilder.prefixes);
+        builder.source = new StringBuilder(pBuilder.source);
+        builder.suffixes = new StringBuilder(pBuilder.suffixes);
+        builder.modifiers = pBuilder.modifiers;
+
+        return builder;
+    }
+
+    public static Builder regex() {
+        return new Builder();
+    }
 
     @Override
     public String toString() {

src/test/java/ru/lanwen/verbalregex/BasicFunctionalityUnitTest.java

@@ -177,7 +177,7 @@ public void testWithAnyCase() {
 
     @Test
     public void testSearchOneLine() {
-        VerbalExpression testRegex = new VerbalExpression.Builder()
+        VerbalExpression testRegex = VerbalExpression.regex()
                 .startOfLine()
                 .then("a")
                 .br()

src/test/java/ru/lanwen/verbalregex/RealWorldUnitTest.java

@@ -2,8 +2,9 @@
 
 import org.junit.Test;
 
+
 import static org.hamcrest.CoreMatchers.equalTo;
-import static org.junit.Assert.assertEquals;
+import static org.hamcrest.core.IsNot.not;
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 
@@ -30,4 +31,31 @@ public void testUrl() {
                 testRegex.toString(),
                 equalTo("^(http)(s)?(\\:\\/\\/)(www\\.)?([^\\ ]*)$"));
     }
+
+    @Test
+    public void staticFabricsRetunSameAsConstructorExpressions() {
+        VerbalExpression regexViaFactory = VerbalExpression.regex().anything().build();
+        VerbalExpression regexViaConstructor = new VerbalExpression.Builder().anything().build();
+
+        assertThat("Factory builder method produce not same as constructor regex",
+                regexViaFactory.toString(), equalTo(regexViaConstructor.toString()));
+    }
+
+    @Test
+    public void clonedBuilderEqualsOriginal() {
+        VerbalExpression.Builder builder = VerbalExpression.regex().anything().addModifier('i');
+        VerbalExpression.Builder clonedBuilder = VerbalExpression.regex(builder);
+
+        assertThat("Cloned builder changed after creating new one",
+                builder.build().toString(), equalTo(clonedBuilder.build().toString()));
+    }
+
+    @Test
+    public void clonedBuilderCantChangeOriginal() {
+        VerbalExpression.Builder builder = VerbalExpression.regex().anything().addModifier('i');
+        VerbalExpression.Builder clonedBuilder = VerbalExpression.regex(builder).endOfLine();
+
+        assertThat("Cloned builder changed after creating new one",
+                builder.build().toString(), not(clonedBuilder.build().toString()));
+    }
 }