From 7156be1328439ae44404db69db6936b1f8480718 Mon Sep 17 00:00:00 2001
From: Roman Dvornov <rdvornov@gmail.com>
Date: Tue, 15 May 2018 15:12:55 +0300
Subject: [PATCH] refactoring of match

---
 lib/lexer/match.js | 30 ++++++++++++------------------
 1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/lib/lexer/match.js b/lib/lexer/match.js
index c6366a04..660909df 100644
--- a/lib/lexer/match.js
+++ b/lib/lexer/match.js
@@ -59,21 +59,18 @@ function internalMatch(tokens, syntax, syntaxes) {
 
     function addTokenToStack() {
         var matchToken = token;
-        var matchTokenCursor = tokenCursor;
 
         moveToNextToken();
 
         matchStack = {
             type: 'Token',
-            size: matchStack.size + 1,
             syntax: syntaxNode,
             token: matchToken,
-            tokenCursor: matchTokenCursor,
             prev: matchStack
         };
 
-        if (matchStack.size > bestMatch.size) {
-            bestMatch = matchStack;
+        if (tokenCursor > longestMatch) {
+            longestMatch = tokenCursor;
         }
 
         return matchToken;
@@ -88,10 +85,8 @@ function internalMatch(tokens, syntax, syntaxes) {
 
         matchStack = {
             type: 'Open',
-            size: matchStack.size,
             syntax: syntaxNode,
             token: matchStack.token,
-            tokenCursor: matchStack.tokenCursor,
             prev: matchStack
         };
     }
@@ -103,10 +98,8 @@ function internalMatch(tokens, syntax, syntaxes) {
         } else {
             matchStack = {
                 type: 'Close',
-                size: matchStack.size,
                 syntax: syntaxStack.syntax,
                 token: matchStack.token,
-                tokenCursor: matchStack.tokenCursor,
                 prev: matchStack
             };
         }
@@ -114,8 +107,8 @@ function internalMatch(tokens, syntax, syntaxes) {
         syntaxStack = syntaxStack.prev;
     }
 
-    var matchStack = { type: 'Stub', size: 0, syntax: null, token: null, tokenCursor: -1, prev: null };
-    var bestMatch = matchStack;
+    var matchStack = { type: 'Stub', syntax: null, token: null, tokenCursor: -1, prev: null };
+    var longestMatch = 0;
     var tokenCursor = -1;
     var token = moveToNextToken();
 
@@ -124,7 +117,7 @@ function internalMatch(tokens, syntax, syntaxes) {
     var elseStack = null;
     var syntaxNode = syntax;
 
-    var LIMIT = 20000;
+    var LIMIT = 5000;
     var iterationCount = 0;
     // var x = syntaxNode;
 
@@ -184,7 +177,7 @@ function internalMatch(tokens, syntax, syntaxes) {
             }
 
             // close syntax if needed
-            if (syntaxStack !== null && thenStack.syntaxStack !== syntaxStack) {
+            while (syntaxStack !== null && thenStack.syntaxStack !== syntaxStack) {
                 closeSyntax();
             }
 
@@ -206,8 +199,8 @@ function internalMatch(tokens, syntax, syntaxes) {
             thenStack = elseStack.thenStack;
             syntaxStack = elseStack.syntaxStack;
             matchStack = elseStack.matchStack;
-            tokenCursor = matchStack.size === 0 ? -1 : matchStack.tokenCursor;
-            token = moveToNextToken();
+            tokenCursor = elseStack.tokenCursor;
+            token = elseStack.token;
 
             // pop stack
             elseStack = elseStack.prev;
@@ -223,6 +216,8 @@ function internalMatch(tokens, syntax, syntaxes) {
                         matchStack: matchStack,
                         syntaxStack: syntaxStack,
                         thenStack: thenStack,
+                        tokenCursor: tokenCursor,
+                        token: token,
                         prev: elseStack
                     };
                 }
@@ -353,7 +348,7 @@ function internalMatch(tokens, syntax, syntaxes) {
     totalIterationCount += iterationCount;
 
     if (syntaxNode === MATCH) {
-        while (syntaxStack) {
+        while (syntaxStack !== null) {
             closeSyntax();
         }
 
@@ -364,8 +359,7 @@ function internalMatch(tokens, syntax, syntaxes) {
             error: null
         };
     } else {
-        tokenCursor = bestMatch.tokenCursor;
-        moveToNextToken();
+        token = tokens[longestMatch >= tokens.length ? tokens.length - 1 : longestMatch];
 
         for (var value = '', offset = 0, i = 0; i < tokens.length; i++) {
             var testToken = tokens[i];