Add word boundary (Fixed #68) (#71)

Author: zawataki

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

@@ -335,6 +335,25 @@ public Builder nonSpace() {
             return this.add("(?:\\S)");
         }
 
+        /**
+         * Add word boundary: \b
+         * <p>
+         * Example:
+         * <pre>{@code
+         * VerbalExpression regex = regex()
+         *         .wordBoundary().find("abc").wordBoundary()
+         *         .build();
+         * regex.test("a abc"); // true
+         * regex.test("a.abc"); // true
+         * regex.test("aabc"); // false
+         * }</pre>
+         *
+         * @return this builder
+         */
+        public Builder wordBoundary() {
+            return this.add("(?:\\b)");
+        }
+
 
         /*
            --- / end of predefined character classes

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

@@ -770,4 +770,17 @@ public void testListOfTextGroups() {
         assertThat(groups1.get(0), equalTo("Hello"));
         assertThat(groups1.get(1), equalTo("World"));
     }
+
+    @Test
+    public void testWordBoundary() {
+        VerbalExpression regex = regex()
+                .capture()
+                .wordBoundary().then("o").word().oneOrMore().wordBoundary()
+                .endCapture()
+                .build();
+
+        assertThat(regex.getText("apple orange grape", 1), is("orange"));
+        assertThat(regex.test("appleorange grape"), is(false));
+        assertThat(regex.test("apple3orange grape"), is(false));
+    }
 }