Performance optimization

lib/jison.js

@@ -722,27 +722,32 @@ lrGeneratorMixin.gotoOperation = function gotoOperation (itemSet, symbol) {
         }
     });
 
-    return gotoSet.isEmpty() ? gotoSet : this.closureOperation(gotoSet);
+    return gotoSet;
 };
 
 /* Create unique set of item sets
  * */
 lrGeneratorMixin.canonicalCollection = function canonicalCollection () {
     var item1 = new this.Item(this.productions[0], 0, [this.EOF]);
-    var firstState = this.closureOperation(new this.ItemSet(item1)),
+    var firstStateNoClosure = new this.ItemSet(item1),
+        firstState = this.closureOperation(firstStateNoClosure),
         states = new Set(firstState),
         marked = 0,
         self = this,
-        itemSet;
+        itemSet,
+        markedSymbols;
 
     states.has = {};
-    states.has[firstState] = 0;
+    states.has[firstStateNoClosure.valueOf()] = 0;
 
     while (marked !== states.size()) {
         itemSet = states.item(marked); marked++;
+        markedSymbols = {};
         itemSet.forEach(function CC_itemSet_forEach (item) {
-            if (item.markedSymbol && item.markedSymbol !== self.EOF)
+            if (item.markedSymbol && !markedSymbols[item.markedSymbol] && item.markedSymbol !== self.EOF){
+                markedSymbols[item.markedSymbol] = true;
                 self.canonicalCollectionInsert(item.markedSymbol, itemSet, states, marked-1);
+            }
         });
     }
 
@@ -751,21 +756,22 @@ lrGeneratorMixin.canonicalCollection = function canonicalCollection () {
 
 // Pushes a unique state into the que. Some parsing algorithms may perform additional operations
 lrGeneratorMixin.canonicalCollectionInsert = function canonicalCollectionInsert (symbol, itemSet, states, stateNum) {
-    var g = this.gotoOperation(itemSet, symbol);
-    if (!g.predecessors)
-        g.predecessors = {};
-    // add g to que if not empty or duplicate
-    if (!g.isEmpty()) {
-        var gv = g.valueOf(),
-            i = states.has[gv];
-        if (i === -1 || typeof i === 'undefined') {
-            states.has[gv] = states.size();
+    var g = this.gotoOperation(itemSet, symbol),
+        state = states.has[g.valueOf()];
+
+    if(state !== undefined){
+        itemSet.edges[symbol] = state; // store goto transition for table
+        states.item(state).predecessors[symbol].push(stateNum);
+    }else{
+        // add g to que if not empty or duplicate
+        if (!g.isEmpty()) {
+            states.has[g.valueOf()] = states.size();
+            g = this.closureOperation(g);
+            if (!g.predecessors)
+                g.predecessors = {};
             itemSet.edges[symbol] = states.size(); // store goto transition for table
             states.push(g);
             g.predecessors[symbol] = [stateNum];
-        } else {
-            itemSet.edges[symbol] = i; // store goto transition for table
-            states.item(i).predecessors[symbol].push(stateNum);
         }
     }
 };

package.json

@@ -2,7 +2,7 @@
   "author": "Zach Carter <[email protected]> (http://zaa.ch)",
   "name": "jison",
   "description": "A parser generator with Bison's API",
-  "version": "0.4.15",
+  "version": "0.4.16",
   "keywords": [
     "jison",
     "bison",