Issue #22 added possibility to stop processing on generating at least one emit

src/main/java/org/ahocorasick/trie/Trie.java

@@ -48,6 +48,11 @@ public class Trie {
         return this;
     }
 
+    public Trie stopOnHit() {
+        this.trieConfig.setStopOnHit(true);
+        return this;
+    }
+
     public void addKeyword(String keyword) {
         if (keyword == null || keyword.length() == 0) {
             return;
@@ -116,7 +121,9 @@ public class Trie {
                 character = Character.toLowerCase(character);
             }
             currentState = getState(currentState, character);
-            storeEmits(position, currentState, emitHandler);
+            if (storeEmits(position, currentState, emitHandler) && trieConfig.isStopOnHit()) {
+                return;
+            }
         }
 
     }
@@ -183,13 +190,16 @@ public class Trie {
         }
     }
 
-    private void storeEmits(int position, State currentState, EmitHandler emitHandler) {
+    private boolean storeEmits(int position, State currentState, EmitHandler emitHandler) {
+        boolean emitted = false;
         Collection<String> emits = currentState.emit();
         if (emits != null && !emits.isEmpty()) {
             for (String emit : emits) {
                 emitHandler.emit(new Emit(position - emit.length() + 1, position, emit));
+                emitted = true;
             }
         }
+        return emitted;
     }
 
 }

src/main/java/org/ahocorasick/trie/TrieConfig.java

@@ -8,6 +8,12 @@ public class TrieConfig {
 
     private boolean caseInsensitive = false;
 
+    private boolean stopOnHit = false;
+
+    public boolean isStopOnHit() { return stopOnHit; }
+
+    public void setStopOnHit(boolean stopOnHit) { this.stopOnHit = stopOnHit; }
+
     public boolean isAllowOverlaps() {
         return allowOverlaps;
     }

src/test/java/org/ahocorasick/trie/TrieTest.java

@@ -41,6 +41,21 @@ public class TrieTest {
         checkEmit(iterator.next(), 0, 2, "bcd");
     }
 
+    @Test
+    public void ushersTestAndStopOnHit() {
+        Trie trie = new Trie();
+        trie.addKeyword("hers");
+        trie.addKeyword("his");
+        trie.addKeyword("she");
+        trie.addKeyword("he");
+        trie.stopOnHit();
+        Collection<Emit> emits = trie.parseText("ushers");
+        assertEquals(2, emits.size()); // she @ 3, he @ 3, hers @ 5
+        Iterator<Emit> iterator = emits.iterator();
+        checkEmit(iterator.next(), 2, 3, "he");
+        checkEmit(iterator.next(), 1, 3, "she");
+    }
+
     @Test
     public void ushersTest() {
         Trie trie = new Trie();