Merge pull request #34 from Tavio/maybe_with_builder

maybe() method now accepts a builder as parameter

Author: lanwen

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

@@ -1,10 +1,10 @@
 package ru.lanwen.verbalregex;
 
+import static java.lang.String.valueOf;
+
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import static java.lang.String.valueOf;
-
 public class VerbalExpression {
 
     private final Pattern pattern;
@@ -170,6 +170,28 @@ public Builder find(final String value) {
         public Builder maybe(final String pValue) {
             return this.then(pValue).add("?");
         }
+        
+        /**
+         * Add a regex to the expression that might appear once (or not)
+         * Example:
+         * The following matches all names that have a prefix or not.
+         * VerbalExpression.Builder namePrefix = regex().oneOf("Mr.", "Ms.");
+	 * VerbalExpression name = regex()
+	 *	.maybe(namePrefix)
+	 *	.space()
+	 *	.zeroOrMore()
+	 *	.word()
+	 *	.oneOrMore()
+	 *	.build();
+         * regex.test("Mr. Bond/")    //true
+         * regex.test("James")   //true
+         *
+         * @param pValue - the string to be looked for
+         * @return this builder
+         */
+        public Builder maybe(final Builder regex) {
+            return this.group().add(regex).endGr().add("?");
+        }
 
         /**
          * Add expression that matches anything (includes empty string)

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

@@ -579,4 +579,20 @@ public void testOneOfWithClosedCapture() {
         assertThat(testRegex.getText("xxxabcdefzzz", 1), equalTo("abcdef"));
         assertThat(testRegex.getText("xxxdefzzz", 1), equalTo("def"));
     }
+    
+    @Test
+    public void shouldAddMaybeWithOneOfFromAnotherBuilder() {
+	VerbalExpression.Builder namePrefix = regex().oneOf("Mr.", "Ms.");
+	VerbalExpression name = regex()
+		.maybe(namePrefix)
+		.space()
+		.zeroOrMore()
+		.word()
+		.oneOrMore()
+		.build();
+	
+	assertThat("Is a name with prefix", name, matchesTo("Mr. Bond"));
+	assertThat("Is a name without prefix", name, matchesTo("James"));
+	
+    }
 }