Add comments, rename variables, remove unused lookahead

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

@@ -21,10 +21,19 @@ package org.ahocorasick.trie;
  */
 class CharacterTransition extends Transition<Character> {
 
+    /**
+     * Create a character transition from a position in the source string
+     * @param c character to match
+     * @param start positon of character in source string
+     */
     public CharacterTransition(Character c, int start) {
         super(c, start, 1);
     }
 
+    /**
+     * Create a character transition without regard for position
+     * @param c character to match
+     */
     public CharacterTransition(Character c) {
         this(c, 0);
     }

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

@@ -16,13 +16,20 @@
 package org.ahocorasick.trie;
 
 /**
+ * Keyword encapsulates part of a potential match along with the count
+ * of prior source tokens consumed to create the potential match.
  *
  * @author doug.lovell
  */
 public class Keyword implements Comparable {
     private final String text;
     private int depth;
-    
+  
+    /**
+     * Create portion of potential match
+     * @param text content that matches
+     * @param depth count of prior source tokens that comprise the match
+     */
     public Keyword(String text, int depth) {
         this.text = text;
         this.depth = depth;
@@ -37,7 +44,10 @@ public class Keyword implements Comparable {
     }
     
     public String toString() {
-        return "Keyword '" + text + "' at depth " + depth;
+        final String t = getText();
+        final int d = getDepth();
+        
+        return "Keyword '" + t + "' at depth " + d;
     }
 
     @Override

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

@@ -27,7 +27,7 @@ import java.util.*;
  */
 public class State {
 
-    /** effective the size of the keyword */
+    /** effectively the size of the keyword */
     private final int depth;
 
     /** only used for the root state to refer to itself in case no matches have been found */
@@ -54,27 +54,27 @@ public class State {
         this.rootState = depth == 0 ? this : null;
     }
 
-    private State nextState(Transition t, boolean ignoreRootState) {
-        State nextState = this.success.get(t);
+    private State nextState(Transition transition, boolean ignoreRootState) {
+        State nextState = this.success.get(transition);
         if (!ignoreRootState && nextState == null && this.rootState != null) {
             nextState = this.rootState;
         }
         return nextState;
     }
 
-    public State nextState(Transition t) {
-        return nextState(t, false);
+    public State nextState(Transition transition) {
+        return nextState(transition, false);
     }
 
-    public State nextStateIgnoreRootState(Transition t) {
-        return nextState(t, true);
+    public State nextStateIgnoreRootState(Transition transition) {
+        return nextState(transition, true);
     }
 
-    public State addState(Transition t) {
-        State nextState = nextStateIgnoreRootState(t);
+    public State addState(Transition transition) {
+        State nextState = nextStateIgnoreRootState(transition);
         if (nextState == null) {
             nextState = new State(this.depth+1);
-            this.success.put(t, nextState);
+            this.success.put(transition, nextState);
         }
         return nextState;
     }
@@ -97,7 +97,7 @@ public class State {
     }
     
     public void addEmitString(String key) {
-        addEmit(new Keyword(key, depth));
+        addEmit(new Keyword(key, getDepth()));
     }
 
     public Collection<Keyword> emit() {

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

@@ -44,8 +44,10 @@ public class Transition<T> {
     
     @Override
     public String toString() {
-        return "Transition on '" + token + "' start: " + start +
-                ", length: " + length;
+        final int s = getStart();
+        final int len = getLength();
+        
+        return "Transition on '" + token + "' start: " + s + ", length: " + len;
     }
     
     @Override

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

@@ -81,9 +81,8 @@ public class Trie {
     }
     
     private class TokenStream {
-        private final KeywordTokenizer kwt;
+        private final KeywordTokenizer tokenizer;
         private final StringBuilder input;
-        private Transition lookahead;
         
         public TokenStream(CharSequence text) {
             input = new StringBuilder(text.length());
@@ -93,23 +92,15 @@ public class Trie {
                         Character.toLowerCase(ch) : ch);
             }
             if (trieConfig.isOnlyWholeWords()) {
-                kwt = new WordTokenizer(input);
+                tokenizer = new WordTokenizer(input);
             }
             else {
-                kwt = new CharacterTokenizer(input);
+                tokenizer = new CharacterTokenizer(input);
             }
-            lookahead = null;
         }
         
         public Transition nextTransition() {
-            Transition next = lookahead;
-            if (next == null) {
-                next = kwt.nextTransition();
-            }
-            else {
-                lookahead = null;
-            }
-            return next;
+            return tokenizer.nextTransition();
         }
         
         public String input() {
@@ -123,13 +114,13 @@ public class Trie {
             return;
         }
         State currentState = this.rootState;
-        TokenStream tknz = new TokenStream(keyword);
-        Transition tn = tknz.nextTransition();
-        while (tn != null) {
-            currentState = currentState.addState(tn);
-            tn = tknz.nextTransition();
+        TokenStream tokenStream = new TokenStream(keyword);
+        Transition transition = tokenStream.nextTransition();
+        while (transition != null) {
+            currentState = currentState.addState(transition);
+            transition = tokenStream.nextTransition();
         }
-        currentState.addEmitString(tknz.input());
+        currentState.addEmitString(tokenStream.input());
     }
 
     public Collection<Token> tokenize(String text) {
@@ -167,25 +158,25 @@ public class Trie {
         
         LinkedList<Transition> tknHistory = new LinkedList<>();
         State currentState = this.rootState;
-        Transition tn = tknz.nextTransition();
-        while (tn != null) {
+        Transition nextTransition = tknz.nextTransition();
+        while (nextTransition != null) {
             if (flushHandler.stop()) {
                 return;
             }
-            tknHistory.add(tn);
-            currentState = getState(currentState, tn, flushHandler);
+            tknHistory.add(nextTransition);
+            currentState = getState(currentState, nextTransition, flushHandler);
             Collection<Keyword> emits = currentState.emit();
             int depth = currentState.getDepth();
             while (depth < tknHistory.size()) {
                 tknHistory.remove();
             }
+            int position = nextTransition.getStart() + nextTransition.getLength();
             for (Keyword emit : emits) {
-                int position = tn.getStart() + tn.getLength();
                 int start = tknHistory.get(depth - emit.getDepth()).getStart();
                 emitCandidateHolder.addCandidate(
                         new Emit(start, position - 1, emit.getText()));
             }
-            tn = tknz.nextTransition();
+            nextTransition = tknz.nextTransition();
         }
         flushHandler.flush();
     }

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

@@ -21,11 +21,20 @@ package org.ahocorasick.trie;
  */
 public class WordTransition extends Transition<String> {
 
-    public WordTransition(String s, int start) {
-        super(s, start, s.length());
+    /**
+     * Create a transition from a position in the source string
+     * @param word to match
+     * @param start position of first character within the source string
+     */
+    public WordTransition(String word, int start) {
+        super(word, start, word.length());
     }
 
-    public WordTransition(String s) {
-        this(s, 0);
+    /**
+     * Create a transition without regard for position
+     * @param word to match
+     */
+    public WordTransition(String word) {
+        this(word, 0);
     }
 }