diff --git a/demos/tree-sitter/matches.md b/demos/tree-sitter/matches.md
index 1d3e5973c..e9ed8d317 100644
--- a/demos/tree-sitter/matches.md
+++ b/demos/tree-sitter/matches.md
@@ -13,9 +13,18 @@
   var vis = await (<treesitter-matches></treesitter-matches>)
 
   // editor1.value =  `let a = 3 + 4`   
-  editor1.value =  `let a = 3`   
+  editor1.value =  `class Test { 
+  foo(i) { 
+    if (i == 0) return "Foo!"
+  } 
+}`   
   // editor2.value = `let a = 3 + 4\na++`      
-  editor2.value = `{let a = 2+4}`      
+  editor2.value = `class Test { 
+  foo(i) { 
+    if (i == 0) return "Bar"
+    else if (i == -1) return "Foo!"
+  } 
+}`      
 
   editor1.editor.on("change", (() => update()).debounce(500));
   editor2.editor.on("change", (() => update()).debounce(500));
diff --git a/src/client/domain-code.js b/src/client/domain-code.js
index 38ffcd20f..d7c7d2391 100644
--- a/src/client/domain-code.js
+++ b/src/client/domain-code.js
@@ -12,10 +12,14 @@ MD*/
 import tinycolor from 'src/external/tinycolor.js';
 
 
-import {Parser, JavaScript, visit as treeSitterVisit} from "src/client/tree-sitter.js"
+import {Parser, JavaScript, visit as treeSitterVisit, match} from "src/client/tree-sitter.js"
 
 import {loc} from "utils"
 
+
+import { ChawatheScriptGenerator} from 'src/client/domain-code/chawathe-script-generator.js';
+
+
 // from: https://stackoverflow.com/questions/7616461/generate-a-hash-from-string-in-javascript
 const cyrb53 = (str, seed = 0) => {
     let h1 = 0xdeadbeef ^ seed, h2 = 0x41c6ce57 ^ seed;
@@ -162,99 +166,23 @@ export class DomainObject {
     
     let { startIndex, oldEndIndex, newEndIndex } = edit
     
-    // 1. detect editit history (diff oldTree -> newTree)
-    // a) deleted nodes from oldTree
-    // b) added nodes in new tree
+    let originalAST = rootDomainObject.treeSitter.tree
+    let originalSource = originalAST.rootNode.text
     
-    // 2. apply diff to domain tree
+    let newAST = TreeSitterDomainObject.fromSource(originalSource)
     
-  
-    function assert(b) { if (!b) throw new Error() }
-    
-    // #TODO use incremental re-parse via edit()
-    const newTree = TreeSitterDomainObject.astFromSource(sourceNew)
     
-    var tsQueue = [newTree.rootNode]
-    var doQueue = [rootDomainObject]
+    if(!originalAST) {throw new Error("originalAST missing")}
+    if(!newAST) {throw new Error("originalAST missing")}
     
-    while (tsQueue.length > 0) {
-      const tsNode = tsQueue.pop();
-      const doNode = doQueue.pop();
-      assert(tsNode.type === doNode.type);
-      
-      const lostChildren = []
-      const missingOldChildren = [...doNode.children]
-      
-      // go over all new children, if we find a new child without an old child, create a new one
-      // if we do find a match, update the treeSitter reference
-      for (let i = 0; i < tsNode.childCount; i++) {
-        const tsChild = tsNode.child(i)
-        const doChild = doNode.children.find(child => tsChild.text === child.treeSitter.text)
-        if (!doChild) {
-          lostChildren.push([i, tsChild])
-        } else {
-          doChild.treeSitter = tsChild
-          missingOldChildren.splice(missingOldChildren.indexOf(tsChild), 1)
-        }
-      }
-      
-      for (const [i, tsChild] of lostChildren) {
-        // we didn't find the exact child but maybe we can keep some of its children, if the
-        // type of the node is still the same (e.g., it's still a function)
-        const candidate = missingOldChildren.find(old => old.treeSitter.type === tsChild.type)
-        if (candidate) {
-          tsQueue.push(tsChild)
-          doQueue.push(candidate)
-          missingOldChildren.splice(missingOldChildren.indexOf(candidate), 1)
-        } else {
-          doNode.children.splice(i, 0, TreeSitterDomainObject.fromTreeSitterAST(tsChild))
-        }
-      }
-      
-      for (const missing of missingOldChildren) {
-        doNode.children.splice(doNode.children.indexOf(missing), 1)
-      }
-    }
-       
-    
-    /*
-    const treeSitterNodesByLocationAndHash = new Map();
-    const remainingNewTreeSitterNodes = new Set()
-    treeSitterVisit(newTree.rootNode, node => {
-      let hash = cyrb53(node.text)
-      let locAndHash = node.startIndex + "-" + node.endIndex + "-" + hash
-      treeSitterNodesByLocationAndHash.set(locAndHash, node)
-      remainingNewTreeSitterNodes.add(node)
-    })
-    
-    function getTreeSitterNodesByLocationAndHash(from, to, hash) {
-      return treeSitterNodesByLocationAndHash.get(from + "-" + to + "-" + hash)
-    }
-    
-    let addedTreeSitterNodes = []
-    let removedDomainObjects = []
+    debugger
+    let mappings = match(originalAST.rootNode, newAST.rootNode, 0, 100)
+    var scriptGenerator = new ChawatheScriptGenerator()
+    scriptGenerator.initWith(originalAST.rootNode, newAST.rootNode, mappings) 
 
-    rootDomainObject.visit(domainObject => {      
-      let adjustedStartIndex = this.adjustIndex(domainObject.treeSitter.startIndex, edit)
-      let adjustedEndIndex = this.adjustIndex(domainObject.treeSitter.endIndex, edit)
-      let hash = cyrb53(domainObject.treeSitter.text)
-      
-      var correspondingNewTreeSitterNode = getTreeSitterNodesByLocationAndHash(adjustedStartIndex, adjustedEndIndex, hash)
-      
-      if (correspondingNewTreeSitterNode) {
-        // take new correspondingNewTreeSitterNode as your own
-        remainingNewTreeSitterNodes.delete(correspondingNewTreeSitterNode)
-      } else {
-        removedDomainObjects.push(domainObject)
-      }
-    })
+    scriptGenerator.generate()
     
-    for(let node of remainingNewTreeSitterNodes) {
-      // create new domain object and put at right position
-      // var newDomainObject  = TreeSitterDomainObject.fromTreeSitterAST()
-    }*/
     
-   
   }
 
   printStructure() {
diff --git a/src/client/tree-sitter.js b/src/client/tree-sitter.js
index 743e672b6..74fbdba16 100644
--- a/src/client/tree-sitter.js
+++ b/src/client/tree-sitter.js
@@ -222,7 +222,7 @@ export function mapTrees(T1, T2, minHeight) {
             if (existTxT2 || existTxT1) {
               candidateMappings.push([t1, t2]);
             } else {
-              visitPairs(t1, t2, (node1, node2) => addMapping(mappings, node1, node2))
+              visitPairs(t1, t2, (node1, node2) => addMapping(mappings, node1, node2,  {phase: "mapTrees_01"}))
             }
           }
         }
@@ -247,7 +247,7 @@ export function mapTrees(T1, T2, minHeight) {
   while (candidateMappings.length > 0) {
     const [t1, t2] = candidateMappings.shift();
 
-    visitPairs(t1, t2, (node1, node2) => addMapping(mappings, node1, node2))
+    visitPairs(t1, t2, (node1, node2) => addMapping(mappings, node1, node2, {phase:"mapTrees_02"}))
 
     candidateMappings = candidateMappings.filter(pair => pair[0] !== t1);
     candidateMappings = candidateMappings.filter(pair => pair[1] !== t2);
@@ -334,6 +334,7 @@ function isLeaf(node) {
 
 function lastChanceMatch(mappings, src, dst, maxSize) {
   if (s(src).size < maxSize || s(dst).size < maxSize) {
+    var debugStartTime = performance.now()
     let zsMappings = zhangShashaMapping(src, dst,
       function children(node) { return node.children },
       function insertCost() { return 1 },
@@ -345,10 +346,14 @@ function lastChanceMatch(mappings, src, dst, maxSize) {
           return 1
         }
       });
+    debugLastChanceCounter++
+    var debugTime = performance.now() - debugStartTime 
+    
     for (let candidate of zsMappings) {
       if (candidate.t1 && candidate.t2) {
         if (!isSrcMapped(mappings, candidate.t1) && !isDstMapped(mappings, candidate.t2)) {
-          addMapping(mappings, candidate.t1, candidate.t2);
+          addMapping(mappings, candidate.t1, candidate.t2, 
+                     {phase: "lastChanceMatch", lastChanceCounter: debugLastChanceCounter, time: debugTime});
         }
       }
     }
@@ -362,7 +367,7 @@ export function hasMapping(mappings, t1, t2) {
   return mappings.find(ea => ea.node2.id == t1.id &&  ea.node2.id == t2.id)
 }
 
-export function addMapping(mappings, t1, t2) {
+export function addMapping(mappings, t1, t2, debugInfo) {
   if (!t1) { throw new Error("t1 is null") }
   if (!t2) { throw new Error("t2 is null") }
   
@@ -371,15 +376,18 @@ export function addMapping(mappings, t1, t2) {
     debugger
     throw new Error("mapping gone wrong?")
   }
-  mappings.push({ node1: t1, node2: t2 })
+  mappings.push({ node1: t1, node2: t2, debugInfo: debugInfo})
 }
 
-function bottomUpPhase(T1, dst, mappings, minDice, maxSize) {
+var debugLastChanceCounter = 0
 
+function bottomUpPhase(T1, dst, mappings, minDice, maxSize) {
+  debugLastChanceCounter = 0
+  
   visitPostorder(T1, t => {
     if (!t.parent) {
       if (!isSrcMapped(mappings, t)) {
-        addMapping(mappings, t, dst)
+        addMapping(mappings, t, dst, {phase: "bottomUpRoot"})
         lastChanceMatch(mappings, t, dst, maxSize);
       }
     } else if (!isSrcMapped(mappings, t) && !isLeaf(t)) {
@@ -396,7 +404,7 @@ function bottomUpPhase(T1, dst, mappings, minDice, maxSize) {
 
       if (best !== null) {
         lastChanceMatch(mappings, t, best, maxSize);
-        addMapping(mappings, t, best)
+        addMapping(mappings, t, best, {phase: "bottomUp"})
       }
     }
   })
@@ -412,6 +420,7 @@ export function match(tree1, tree2, minHeight = 2, maxSize = 100, minDice=0.5) {
 
   let matches = mapTrees(tree1, tree2, minHeight)
 
+  
   bottomUpPhase(tree1, tree2, matches, minDice, maxSize)
 
   return Array.from(matches);
diff --git a/src/components/tools/treesitter-matches.js b/src/components/tools/treesitter-matches.js
index 0b74e20b7..51060c078 100644
--- a/src/components/tools/treesitter-matches.js
+++ b/src/components/tools/treesitter-matches.js
@@ -11,7 +11,7 @@ export default class TreesitterMatches extends Morph {
   get livelyUpdateStrategy() { return 'inplace'; }
   
   async update() {
-    let graphviz = await (<graphviz-dot></graphviz-dot>)
+    let graphviz = await (<graphviz-dot style="width: 2000px"></graphviz-dot>)
 
     function renderTree(rootNode, clusterName) {
       let dotEdges = []
@@ -28,11 +28,51 @@ export default class TreesitterMatches extends Morph {
       }`
 
     }
+    
+    function colorForPhase(phase) {
+      var colors = {
+        mapTrees_01: "green",
+        mapTrees_02: "green",
+        lastChanceMatch: "blue",
+        bottomUp: "red",
+        bottomUpRoot: "orange"
+      }
+      
+      if (!colors[phase]) {
+        debugger
+      }
+      
+      return colors[phase] || "gray"
+    }
+    
+    function labelFor(match) {
+      if (match.debugInfo && match.debugInfo.phase === "lastChanceMatch") {
+        return match.debugInfo.lastChanceCounter
+      }
+      return ""
+    }
+    
+    function tooltipFor(match) {
+      if (!match.debugInfo) return ""
+      var s = match.debugInfo.phase
+      if (match.debugInfo.time) {
+        s += " " + match.debugInfo.time +"ms"
+      }
+      return s 
+    }
+    
+    function widthFor(match) {
+      if (match.debugInfo  && match.debugInfo.time) {
+        return match.debugInfo.time * 1
+      }
+      return 1
+    }
+    
 
     function renderMatches(matches)  {
       let dotEdges  = []
       for(let match of matches) {
-        dotEdges.push(`${match.node1.id} -> ${match.node2.id} [color=green]`)
+        dotEdges.push(`${match.node1.id} -> ${match.node2.id} [color="${match.debugInfo ? colorForPhase(match.debugInfo.phase) : "gray"}" penwidth="${widthFor(match)}" tooltip="${tooltipFor(match)}" label="${labelFor(match)}"]`)
       }
       return dotEdges.join(";\n")
     }
@@ -63,10 +103,19 @@ export default class TreesitterMatches extends Morph {
     var parser = new Parser();
     parser.setLanguage(JavaScript);
 
-    let sourceCode1 = `let a = 3 + 4`      
+    let sourceCode1 = `class Test { 
+  foo(i) { 
+    if (i == 0) return "Foo!"
+  } 
+}`      
     this.tree1 = parser.parse(sourceCode1);
 
-    let sourceCode2 = `let a = 3 + 4\na++`      
+    let sourceCode2 = `class Test { 
+  foo(i) { 
+    if (i == 0) return "Bar"
+    else if (i == -1) return "Foo!"
+  } 
+}`      
     this.tree2 = parser.parse(sourceCode2);
 
     this.matches = match(this.tree1.rootNode, this.tree2.rootNode)
diff --git a/test/domain-code-test.js b/test/domain-code-test.js
index 7fb96e967..412abb757 100644
--- a/test/domain-code-test.js
+++ b/test/domain-code-test.js
@@ -105,7 +105,7 @@ l`
       expect(root.children[0].children[0].type).equals("assignment_expression")
     })
     
-     xit('reconciles change when removing statement at end', () => {
+     it('reconciles change when removing statement at end', () => {
       let sourceOriginal = `a = 3
 l`
       let sourceNew = `a = 3`