diff --git a/packages/DomainCode-Core/DCQuery.class.st b/packages/DomainCode-Core/DCQuery.class.st
index 4d64b87..d1490bf 100644
--- a/packages/DomainCode-Core/DCQuery.class.st
+++ b/packages/DomainCode-Core/DCQuery.class.st
@@ -60,6 +60,12 @@ DCQuery class >> removeProperty: anObject from: aDomainObject [
 		ifPresent: [:properties | properties remove: aDomainObject]
 ]
 
+{ #category : #'as yet unclassified' }
+DCQuery class >> script: aCollection allDeep: anotherCollection [
+
+	^ Array streamContents: [:s | anotherCollection allChildrenDo: [:obj | (self script: aCollection with: obj) ifNotNil: [:res | s nextPut: res]]]
+]
+
 { #category : #'as yet unclassified' }
 DCQuery class >> script: aCollection first: anotherCollection [
 
@@ -67,6 +73,13 @@ DCQuery class >> script: aCollection first: anotherCollection [
 	^ nil
 ]
 
+{ #category : #'as yet unclassified' }
+DCQuery class >> script: aCollection firstDeep: anotherCollection [
+
+	anotherCollection allChildrenDo: [:obj | (self script: aCollection with: obj) ifNotNil: [:res | ^ res]].
+	^ nil
+]
+
 { #category : #'as yet unclassified' }
 DCQuery class >> script: aCollection with: anObject [
 
diff --git a/packages/DomainCode-Core/Morph.extension.st b/packages/DomainCode-Core/Morph.extension.st
index 6d72c41..eeb4227 100644
--- a/packages/DomainCode-Core/Morph.extension.st
+++ b/packages/DomainCode-Core/Morph.extension.st
@@ -14,7 +14,7 @@ Morph >> allChildrenBreadthFirstDo: aBlock [
 { #category : #'*DomainCode-Core' }
 Morph >> allChildrenDo: aBlock [
 
-	self children do: [:c | c allChildrenDo: aBlock].
+	self childrenDo: [:c | c allChildrenDo: aBlock].
 	aBlock value: self
 ]
 
@@ -37,12 +37,33 @@ Morph >> allDomainBlocksWithDepthDo: aBlock leafDo: anotherBlock depth: aNumber
 	anotherBlock value: self value: aNumber
 ]
 
+{ #category : #'*DomainCode-Core' }
+Morph >> childCount [
+
+	| i |
+	i := 0.
+	self childrenDo: [:c | i := i + 1].
+	^ i
+]
+
 { #category : #'*DomainCode-Core' }
 Morph >> children [
 
 	^ submorphs
 ]
 
+{ #category : #'*DomainCode-Core' }
+Morph >> childrenDo: aBlock [
+
+	submorphs do: aBlock
+]
+
+{ #category : #'*DomainCode-Core' }
+Morph >> childrenSelect: aBlock [
+
+	^ Array streamContents: [:s | self childrenDo: [:c | (aBlock value: c) ifTrue: [s nextPut: c]]]
+]
+
 { #category : #'*DomainCode-Core' }
 Morph >> firstDeepChildNode [
 
@@ -55,7 +76,8 @@ Morph >> firstDeepChildNode [
 { #category : #'*DomainCode-Core' }
 Morph >> hasChildren [
 
-	^ self children notEmpty
+	self childrenDo: [:c | ^ true].
+	^ false
 ]
 
 { #category : #'*DomainCode-Core' }
diff --git a/packages/DomainCode-Diff/DCChawatheScriptGenerator.class.st b/packages/DomainCode-Diff/DCChawatheScriptGenerator.class.st
index 8b838af..16b6f54 100644
--- a/packages/DomainCode-Diff/DCChawatheScriptGenerator.class.st
+++ b/packages/DomainCode-Diff/DCChawatheScriptGenerator.class.st
@@ -8,11 +8,11 @@ Class {
 DCChawatheScriptGenerator >> alignChildrenSrc: w dest: x srcInOrder: srcInOrder destInOrder: destInOrder in: aMapping [
 
 	| s1 s2 lcs |
-	w children do: [:c | srcInOrder remove: c ifAbsent: []].
-	x children do: [:c | destInOrder remove: c ifAbsent: []].
+	w childrenDo: [:c | srcInOrder remove: c ifAbsent: []].
+	x childrenDo: [:c | destInOrder remove: c ifAbsent: []].
 	
-	s1 := w children select: [:c | (aMapping isSrcMapped: c) and: [x children includes: (aMapping destForSrc: c)]].
-	s2 := x children select: [:c | (aMapping isDestMapped: c) and: [w children includes: (aMapping srcForDest: c)]].
+	s1 := w childrenSelect: [:c | (aMapping isSrcMapped: c) and: [x children includes: (aMapping destForSrc: c)]].
+	s2 := x childrenSelect: [:c | (aMapping isDestMapped: c) and: [w children includes: (aMapping srcForDest: c)]].
 	
 	lcs := self lcsWith: s1 and: s2 in: aMapping.
 	lcs do: [:mapping |
diff --git a/packages/DomainCode-Diff/DCMappingComparator.class.st b/packages/DomainCode-Diff/DCMappingComparator.class.st
index eba206e..d9d6f2e 100644
--- a/packages/DomainCode-Diff/DCMappingComparator.class.st
+++ b/packages/DomainCode-Diff/DCMappingComparator.class.st
@@ -9,7 +9,8 @@ Class {
 		'destAncestors',
 		'rootSrc',
 		'rootDest',
-		'absolutePositions'
+		'absolutePositions',
+		'indicesInParents'
 	],
 	#category : #'DomainCode-Diff'
 }
@@ -102,17 +103,17 @@ DCMappingComparator >> longestCommonSubsequenceWith: aCollection and: anotherCol
 	1 to: aCollection size do: [:i |
 		1 to: anotherCollection size do: [:j |
 			(aCollection at: i) type = (anotherCollection at: j) type
-				ifTrue: [lengths at: i + 1 at: j + 1 put: (lengths at: i at: j)]
-				ifFalse: [lengths at: i + 1 at: j + 1 put: ((lengths at: i + 1 at: j) max: (lengths at: i at: j + 1))]]].
+				ifTrue: [lengths atFast: i + 1 at: j + 1 put: (lengths atFast: i at: j)]
+				ifFalse: [lengths atFast: i + 1 at: j + 1 put: ((lengths atFast: i + 1 at: j) max: (lengths at: i at: j + 1))]]].
 	
 	indices := OrderedCollection new.
 	x := aCollection size + 1.
 	y := anotherCollection size + 1.
 	[x > 1 and: [y > 1]] whileTrue: [
-		(lengths at: x at: y) = (lengths at: x - 1 at: y)
+		(lengths atFast: x at: y) = (lengths atFast: x - 1 at: y)
 			ifTrue: [x := x - 1]
 			ifFalse: [
-				(lengths at: x at: y) = (lengths at: x at: y - 1)
+				(lengths atFast: x at: y) = (lengths atFast: x at: y - 1)
 					ifTrue: [y := y - 1]
 					ifFalse: [
 						indices add: {x - 1. y - 1}.
@@ -193,9 +194,12 @@ DCMappingComparator >> similarityPositionInParentsCompare: aMapping with: anothe
 			indices add: current siblingIndex.
 			current := current parent].
 		indices].
+	
+	indicesInParents ifNil: [indicesInParents := Dictionary new].
+	
 	distance := [:mapping | | indicesVec1 indicesVec2 sum |
-		indicesVec1 := indicesInOwnerSubmorphs value: mapping first.
-		indicesVec2 := indicesInOwnerSubmorphs value: mapping second.
+		indicesVec1 := indicesInParents at: mapping first ifAbsentPut: [indicesInOwnerSubmorphs value: mapping first].
+		indicesVec2 := indicesInParents at: mapping second ifAbsentPut: [indicesInOwnerSubmorphs value: mapping second].
 		sum := 0.0.
 		1
 			to: (indicesVec1 size min: indicesVec2 size)
diff --git a/packages/DomainCode-Diff/DCMatcher.class.st b/packages/DomainCode-Diff/DCMatcher.class.st
index ce760c5..b6ff13d 100644
--- a/packages/DomainCode-Diff/DCMatcher.class.st
+++ b/packages/DomainCode-Diff/DCMatcher.class.st
@@ -102,6 +102,8 @@ DCMatcher >> matchFrom: src to: dest [
 { #category : #'as yet unclassified' }
 DCMatcher >> performEditsIn: aDest to: aSrc [
 
+	aSrc allChildrenDo: [:m | m clearDiffCache].
+	
 	DCChawatheScriptGenerator new
 		generateFrom: aSrc
 		to: aDest
diff --git a/packages/DomainCode-Parser/DCBlock.class.st b/packages/DomainCode-Parser/DCBlock.class.st
index 2accb0b..d30d7cb 100644
--- a/packages/DomainCode-Parser/DCBlock.class.st
+++ b/packages/DomainCode-Parser/DCBlock.class.st
@@ -351,7 +351,7 @@ DCBlock class >> smalltalkDeclaration [
 
 	^ {
 		[:x | x language = SBTSSmalltalk].
-		[:x | #(#identifier #'block_argument') includes: x type].
+		[:x | x is: #(#identifier #'block_argument')].
 		[:id | {#args. id. id orAllParents: #(#method #block)}].
 		[:id :scopes | | decl |
 			decl := ((DCQuery
@@ -371,8 +371,11 @@ DCBlock class >> smalltalkDeclaration [
 											detect: [:arg | (arg contents withoutLeading: #($:)) = (id contents withoutLeading: #($:))]
 											ifNone: [nil]]}.
 								{
-									[:method | "method args"
-									method queryAll: '[(keyword_selector (identifier) @) (binary_selector (identifier) @)]'].
+									[:method |
+										"method args"
+										method queryFirst: {
+											[:x | x is: {#'binary_selector'. #'keyword_selector'}].
+											[:x | x children select: [:c | c is: #identifier]]}].
 									[:args | args detect: [:arg | arg contents = id contents] ifNone: [nil]]}}
 							with: scope]}
 				first: scopes) ifNil: [
@@ -581,8 +584,9 @@ DCBlock class >> smalltalkMessageSendAutoCompletion [
 		[:x | "only autocomplete for the first message part (just after receiver)"
 		x childIndex = 2].
 		[:x | (DCQuery script: self smalltalkMessageSendSelector with: x) ifNotNil: [:res | res, {x}]].
+		[:selector :message :part | selector size > 2].
 		[:selector :message :part |
-			part addSuggestions: ((self sortedSuggestions: Symbol allSymbols for: selector addAll: false max: 10) collect: [:sel |
+			part addSuggestions: ((self sortedSymbolSuggestionsFor: selector max: 10) collect: [:sel |
 				DCSuggestionItem new
 					selector: sel label: 'send' source: ((sel allSatisfy: #isSpecial) ifTrue: [sel, ' __sb'] ifFalse: [
 						(sel includes: $:)
@@ -604,8 +608,7 @@ DCBlock class >> smalltalkMessageSendSelector [
 
 	^ {
 		self smalltalkMessageSend.
-		[:message | {#args. message queryAll: '[(keyword) (binary_operator) (unary_identifier)] @part'. message}].
-		[:hits :message | {#args. hits select: [:part | part owner = message]. message}].
+		[:message | {#args. message children select: [:c | c is: #(#keyword #'binary_operator' #'unary_identifier')]. message}].
 		[:hits :message | {#args. hits collect: #contents. message}].
 		[:parts :message | {#args. parts joinSeparatedBy: ''. message}]}
 ]
@@ -685,7 +688,7 @@ DCBlock class >> smalltalkSelector [
 								#args.
 								DCQuery
 									script: {
-										[:s | s queryAll: '[(keyword) (binary_operator) (unary_identifier)] @part'].
+										[:s | s children select: [:c | c is: #(#keyword #'binaary_operator' #'unary_identifier')]].
 										[:hits | (hits collect: #contents) joinSeparatedBy: '']}
 									with: sel.
 								sel}]}}
@@ -1023,7 +1026,7 @@ DCBlock >> applyEdit: edit source: newSource cursorAt: newIndex undoDo: aBlock [
 			self sandblockEditor do: (SBDoItCommand new
 				do: apply;
 				undo: [
-					oldTree tryApplyChange: [:source |
+					oldTree infoForEditDo: [:source |
 						aBlock
 							value: source
 							value: [:new :undoEdit :undo | oldTree applyEdit: undoEdit source: new cursorAt: undoEdit newEndByte undoDo: nil]]])]
@@ -1106,21 +1109,31 @@ DCBlock >> childNodes [
 { #category : #'as yet unclassified' }
 DCBlock >> children [
 
-	^ Array streamContents: [:s | super children do: [:c | c isReplacement ifTrue: [c resolveSource ifNotNil: [:child | s nextPut: child]] ifFalse: [s nextPut: c]]]
+	^ Array streamContents: [:s | self childrenDo: [:c | s nextPut: c]]
 ]
 
 { #category : #'as yet unclassified' }
-DCBlock >> clearCache [
+DCBlock >> childrenDo: aBlock [
 
-	super clearCache.
-	self removeProperty: #treeHash
+	^ self submorphs do: [:c |
+		c isReplacement
+			ifTrue: [c resolveSource ifNotNil: [:child | aBlock value: child]]
+			ifFalse: [aBlock value: c]]
+]
+
+{ #category : #hierarchy }
+DCBlock >> clearDiffCache [
+
+	self removeProperty: #treeHash.
+	self removeProperty: #treeSize.
+	self removeProperty: #treeHeight
 ]
 
 { #category : #'as yet unclassified' }
 DCBlock >> clearInput [
 	<action>
 
-	self tryApplyChange: [:source :textMorph | self class replace: self activeTextMorph range in: source with: '' do: self applyBlock]
+	self infoForEditDo: [:source :textMorph | self class replace: (self activeTextMorph ifNil: [self]) range in: source with: '' do: self applyBlock]
 ]
 
 { #category : #'as yet unclassified' }
@@ -1161,7 +1174,7 @@ DCBlock >> currentTextMorph [
 DCBlock >> deleteAfterCursor [
 	<action>
 
-	self tryApplyChange: [:source :textMorph :cursorIndex | self class deleteFrom: source at: cursorIndex + 1 do: self applyBlock].
+	self infoForEditDo: [:source :textMorph :cursorIndex | self class deleteFrom: source at: cursorIndex + 1 do: self applyBlock].
 	self batchedChangeStep
 ]
 
@@ -1169,7 +1182,7 @@ DCBlock >> deleteAfterCursor [
 DCBlock >> deleteBeforeCursor [
 	<action>
 
-	self tryApplyChange: [:source :textMorph :cursorIndex | self class deleteFrom: source at: cursorIndex do: self applyBlock].
+	self infoForEditDo: [:source :textMorph :cursorIndex | self class deleteFrom: source at: cursorIndex do: self applyBlock].
 	self batchedChangeStep
 ]
 
@@ -1179,7 +1192,7 @@ DCBlock >> deleteBlock [
 
 	self isArtefact ifTrue: [^ super deleteBlock].
 	
-	self tryApplyChange: [:source :textMorph :cursorIndex | | delRange |
+	self infoForEditDo: [:source :textMorph :cursorIndex | | delRange |
 		delRange := textMorph range.
 		self trailingTerminator ifNotNil: [:t |
 			delRange := SBTSRange merging: {delRange. t range}.
@@ -1365,11 +1378,17 @@ DCBlock >> handleInsertEvent: anEvent in: textMorph [
 { #category : #hierarchy }
 DCBlock >> hasAnyParent: aBlock [
 
+	| p |
 	self isRootBlock ifTrue: [^ false].
 	
-	self parent = aBlock ifTrue: [^ true].
+	p := self parent.
+	p ifNil: [
+		self assert: self type = 'ERROR'.
+		^ false].
 	
-	^ self parent hasAnyParent: aBlock
+	p = aBlock ifTrue: [^ true].
+	
+	^ p hasAnyParent: aBlock
 ]
 
 { #category : #hierarchy }
@@ -1404,6 +1423,21 @@ DCBlock >> indentFor: aBlock current: aNumber [
 		ifFalse: [aNumber]
 ]
 
+{ #category : #'as yet unclassified' }
+DCBlock >> infoForEditDo: aClosure [
+
+	| oldCursorOffset oldSource |
+	oldCursorOffset := self activeTextMorph ifNotNil: #cursor.
+	oldSource := self rootBlock privateSource.
+	
+	aClosure valueWithEnoughArguments: {
+		oldSource.
+		self activeTextMorph ifNil: [self].
+		self activeTextMorph
+			ifNotNil: [self activeTextMorph range start index + (oldCursorOffset - 1)]
+			ifNil: [self range]}
+]
+
 { #category : #'as yet unclassified' }
 DCBlock >> initialize [
 
@@ -1462,7 +1496,7 @@ DCBlock >> inputClosestTextMorphTo: cursorPosition [
 { #category : #'as yet unclassified' }
 DCBlock >> insert: aString [
 
-	self tryApplyChange: [:source :textMorph :cursorIndex | self class insert: aString in: source at: cursorIndex + 1 do: self applyBlock].
+	self infoForEditDo: [:source :textMorph :cursorIndex | self class insert: aString in: source at: cursorIndex + 1 do: self applyBlock].
 	self batchedChangeStep
 ]
 
@@ -1494,7 +1528,7 @@ DCBlock >> insertStatementAboveOrBelow: anAboveBoolean [
 		
 		point := anAboveBoolean ifTrue: [target range start] ifFalse: [target range end].
 		index := point index.
-		self tryApplyChange: [:source |
+		self infoForEditDo: [:source |
 			self class
 				insert: String cr, indent
 				in: source
@@ -1579,6 +1613,16 @@ DCBlock >> intoWorld: aWorld [
 			updateQueriesFor: #always]
 ]
 
+{ #category : #hierarchy }
+DCBlock >> is: aCollectionOrSymbol [
+
+	| matches |
+	matches := aCollectionOrSymbol isSymbol
+		ifTrue: [{aCollectionOrSymbol}]
+		ifFalse: [aCollectionOrSymbol].
+	^ matches includes: self type
+]
+
 { #category : #'as yet unclassified' }
 DCBlock >> isArtefact [
 
@@ -1648,7 +1692,7 @@ DCBlock >> isTSMorph [
 { #category : #'as yet unclassified' }
 DCBlock >> keyStroke: anEvent [
 
-	self tryApplyChange: [:source :textMorph :cursorIndex | | input |
+	self infoForEditDo: [:source :textMorph :cursorIndex | | input |
 		input := anEvent keyCharacter asString.
 		(input first isPrintable and: [anEvent commandKeyPressed not]) ifTrue: [
 			(self adaptInput: input in: source at: cursorIndex textMorph: textMorph event: anEvent) ifNotEmpty: [:text |
@@ -1716,16 +1760,6 @@ DCBlock >> minBoundsWith: info [
 	^ info bounds
 ]
 
-{ #category : #'as yet unclassified' }
-DCBlock >> noteNewOwner: aMorph [
-
-	super noteNewOwner: aMorph.
-	
-	"check if we have just been moved out of a replacement"
-	(self replacedParent notNil and: [aMorph notNil and: [aMorph class = DCBlock]]) ifTrue: ["self replacedParent: nil"
-	]
-]
-
 { #category : #hierarchy }
 DCBlock >> orAllParents: aCollectionOrSymbol [
 
@@ -1809,7 +1843,7 @@ DCBlock >> parentNode [
 DCBlock >> pasteReplace [
 	<action>
 
-	self tryApplyChange: [:source :textMorph :cursorIndex | | str |
+	self infoForEditDo: [:source :textMorph :cursorIndex | | str |
 		str := Clipboard clipboardText string.
 		
 		cursorIndex class = SBTSRange
@@ -1860,7 +1894,7 @@ DCBlock >> prefersNoBorder [
 { #category : #'as yet unclassified' }
 DCBlock >> prettyPrint [
 
-	self tryApplyChange: [:source | | new |
+	self infoForEditDo: [:source | | new |
 		new := [
 			PPFormatter
 				formatString: source
@@ -1868,11 +1902,12 @@ DCBlock >> prettyPrint [
 				noPattern: false]
 			on: SyntaxErrorNotification
 			do: [source].
-		self
-			applyEdit: nil
-			source: new
-			cursorAt: 1
-			undoDo: [:undoSource :block | block value: source value: nil value: nil]]
+		source = new ifFalse: [
+			self
+				applyEdit: nil
+				source: new
+				cursorAt: 1
+				undoDo: [:undoSource :block | block value: source value: nil value: nil]]]
 ]
 
 { #category : #'as yet unclassified' }
@@ -1943,6 +1978,8 @@ DCBlock >> privateTSTreeOrNilDo: aBlock [
 { #category : #'as yet unclassified' }
 DCBlock >> queryAll: aString [
 
+	aString isString ifFalse: [^ DCQuery script: aString allDeep: self].
+	
 	self assert: (aString includes: $@) description: 'query needs a capture (@) to be useful'.
 	
 	^ Array streamContents: [:stream |
@@ -1969,6 +2006,8 @@ DCBlock >> queryChildrenFirst: aString [
 { #category : #'as yet unclassified' }
 DCBlock >> queryFirst: aString [
 
+	aString isString ifFalse: [^ DCQuery script: aString firstDeep: self].
+	
 	self assert: (aString includes: $@) description: 'query needs a capture (@) to be useful'.
 	
 	self allChildrenDo: [:block |
@@ -2049,7 +2088,7 @@ DCBlock >> replace: oldTree with: newTree [
 { #category : #'as yet unclassified' }
 DCBlock >> replaceWith: aString [
 
-	self tryApplyChange: [:source :textMorph :cursorIndex | self class replace: textMorph range in: source with: aString do: self applyBlock]
+	self infoForEditDo: [:source :textMorph :cursorIndex | self class replace: textMorph range in: source with: aString do: self applyBlock]
 ]
 
 { #category : #accessing }
@@ -2088,6 +2127,13 @@ DCBlock >> run: aCollection [
 	^ DCQuery script: aCollection with: self
 ]
 
+{ #category : #'as yet unclassified' }
+DCBlock >> sandblockEditor [
+
+	" allow embedded nodes to access the editor "
+	^ (self owner ifNil: [self parent]) ifNotNil: [:o | o sandblockEditor]
+]
+
 { #category : #'as yet unclassified' }
 DCBlock >> saveTryFixing: aFixBoolean quick: aQuickBoolean [
 
@@ -2109,11 +2155,17 @@ DCBlock >> shallowCopyBlock [
 { #category : #hierarchy }
 DCBlock >> siblingIndex [
 
+	| i p |
 	self replacedParent ifNotNil: [^ self replacedParent siblingIndex].
 	
-	self parent ifNil: [^ 0].
+	p := self parent.
+	p ifNil: [^ 0].
 	
-	^ self parent children indexOf: self
+	i := 1.
+	p childrenDo: [:c |
+		c = self ifTrue: [^ i].
+		i := i + 1].
+	^ 0
 ]
 
 { #category : #'as yet unclassified' }
@@ -2182,7 +2234,7 @@ DCBlock >> suggestions [
 { #category : #'as yet unclassified' }
 DCBlock >> swap: aNumber [
 
-	self tryApplyChange: [:source :textMorph :cursorIndex | | pivot outerPivot |
+	self infoForEditDo: [:source :textMorph :cursorIndex | | pivot outerPivot |
 		pivot := (self sandblockEditor mode = #input
 			ifTrue: [textMorph]
 			ifFalse: [self]) orOwnerSuchThat: [:morph | morph owner submorphCount > 1].
@@ -2236,14 +2288,14 @@ DCBlock >> trailingTerminator [
 { #category : #'as yet unclassified' }
 DCBlock >> treeHash [
 
-	true ifTrue: [^ self treeHashCount: {0}].
+	false ifTrue: [^ self treeHashCount: {0}].
 	^ self valueOfProperty: #treeHash ifAbsentPut: [self treeHashCount: {0}]
 ]
 
 { #category : #'as yet unclassified' }
 DCBlock >> treeHashChildren: anotherNumber [
 
-	^ ((((self type hash bitXor: 'ENTER' hash) bitXor: anotherNumber) bitXor: self siblingIndex hash) bitXor: self children size) bitXor: 'LEAVE' hash
+	^ ((((self type hash bitXor: 'ENTER' hash) bitXor: anotherNumber) bitXor: self siblingIndex hash) bitXor: self childCount) bitXor: 'LEAVE' hash
 ]
 
 { #category : #'as yet unclassified' }
@@ -2251,37 +2303,39 @@ DCBlock >> treeHashChildren: anotherNumber countPtr: aCollection [
 
 	aCollection at: 1 put: aCollection first + 1.
 	
-	^ ((((self type hash + 'ENTER' hash) + anotherNumber) bitXor: (2 * aCollection first + 1) hash) bitXor: self children size) bitXor: 'LEAVE' hash
+	^ ((self type hash + 'ENTER' hash + anotherNumber bitXor: (2 * aCollection first + 1) hash) bitXor: self childCount) bitXor: 'LEAVE' hash
 ]
 
 { #category : #'as yet unclassified' }
 DCBlock >> treeHashCount: aPtr [
 
+	| hash |
 	self hasChildren ifFalse: [^ self treeHashChildren: 0 countPtr: aPtr].
+	hash := 0.
+	
+	self childrenDo: [:morph | hash := (hash + (morph treeHashCount: aPtr)) hashMultiply].
+	
 	^ self
-		treeHashChildren: (self children inject: 0 into: [:hash :morph | hash bitXor: (morph treeHashCount: aPtr)])
+		treeHashChildren: hash
 		countPtr: aPtr
 ]
 
+{ #category : #'as yet unclassified' }
+DCBlock >> treeHeight [
+
+	^ self valueOfProperty: #treeHeight ifAbsentPut: [super treeHeight]
+]
+
 { #category : #'as yet unclassified' }
 DCBlock >> treeLabel [
 
 	^ ''
 ]
 
-{ #category : #'as yet unclassified' }
-DCBlock >> tryApplyChange: aClosure [
+{ #category : #hierarchy }
+DCBlock >> treeSize [
 
-	| oldCursorOffset oldSource |
-	oldCursorOffset := self activeTextMorph ifNotNil: #cursor.
-	oldSource := self rootBlock privateSource.
-	
-	aClosure valueWithEnoughArguments: {
-		oldSource.
-		self activeTextMorph ifNil: [self].
-		self activeTextMorph
-			ifNotNil: [self activeTextMorph range start index + (oldCursorOffset - 1)]
-			ifNil: [self range]}
+	^ self valueOfProperty: #treeSize ifAbsentPut: [super treeSize]
 ]
 
 { #category : #'as yet unclassified' }
@@ -2314,7 +2368,7 @@ DCBlock >> updateAllHighlights [
 { #category : #'as yet unclassified' }
 DCBlock >> useSuggestion: anItem [
 
-	self tryApplyChange: [:source :textMorph :cursorIndex | self class replace: textMorph range in: source with: anItem source do: self applyBlock]
+	self infoForEditDo: [:source :textMorph :cursorIndex | self class replace: textMorph range in: source with: anItem source do: self applyBlock]
 ]
 
 { #category : #'as yet unclassified' }
@@ -2374,7 +2428,7 @@ DCBlock >> wrapInSquareBrackets [
 { #category : #'as yet unclassified' }
 DCBlock >> wrapWithBefore: aString after: anotherString [
 
-	self tryApplyChange: [:source :textMorph :cursorIndex |
+	self infoForEditDo: [:source :textMorph :cursorIndex |
 		self class
 			replace: textMorph range
 			in: source
diff --git a/packages/DomainCode-Parser/DCEmptyStatement.class.st b/packages/DomainCode-Parser/DCEmptyStatement.class.st
index 18ba95c..c68b10d 100644
--- a/packages/DomainCode-Parser/DCEmptyStatement.class.st
+++ b/packages/DomainCode-Parser/DCEmptyStatement.class.st
@@ -51,7 +51,7 @@ DCEmptyStatement >> insertSeparatorAfter: aBoolean [
 DCEmptyStatement >> pasteReplace [
 	<action>
 
-	self tryApplyChange: [:source :textMorph :cursorIndex | | str |
+	self infoForEditDo: [:source :textMorph :cursorIndex | | str |
 		str := Clipboard clipboardText string.
 		str := self insertSeparatorAfter
 			ifTrue: [str, self language statementTerminator]
diff --git a/packages/DomainCode-Parser/DCJumpPlaceholder.class.st b/packages/DomainCode-Parser/DCJumpPlaceholder.class.st
index 3253d6d..556f234 100644
--- a/packages/DomainCode-Parser/DCJumpPlaceholder.class.st
+++ b/packages/DomainCode-Parser/DCJumpPlaceholder.class.st
@@ -4,18 +4,6 @@ Class {
 	#category : #'DomainCode-Parser'
 }
 
-{ #category : #'as yet unclassified' }
-DCJumpPlaceholder >> adaptInput: input in: source at: cursorIndex textMorph: textMorph event: anEvent [
-
-	(super adaptInput: input in: source at: cursorIndex textMorph: textMorph event: anEvent) ifNotEmpty: [:newInput |
-		self
-			replace: self range
-			in: source
-			with: newInput
-			do: [:new :edit | self applyEdit: edit source: new cursorAt: cursorIndex + 1]].
-	^ ''
-]
-
 { #category : #'as yet unclassified' }
 DCJumpPlaceholder >> initialize [
 
@@ -25,16 +13,24 @@ DCJumpPlaceholder >> initialize [
 ]
 
 { #category : #'as yet unclassified' }
-DCJumpPlaceholder >> isJumpPoint [
-
-	^ true
+DCJumpPlaceholder >> keyStroke: anEvent [
+
+	(anEvent keyCharacter isPrintable and: [anEvent commandKeyPressed not]) ifTrue: [
+		self source infoForEditDo: [:source :textMorph :cursorIndex |
+			self source replaceWith: (self source
+				adaptInput: anEvent keyCharacter asString
+				in: source
+				at: cursorIndex
+				textMorph: textMorph
+				event: anEvent)]].
+	self batchedChangeStep
 ]
 
 { #category : #'as yet unclassified' }
 DCJumpPlaceholder >> pasteReplace [
 	<action>
 
-	self tryApplyChange: [:source :textMorph :cursorIndex | | str |
+	self infoForEditDo: [:source :textMorph :cursorIndex | | str |
 		str := Clipboard clipboardText string.
 		
 		self
diff --git a/packages/DomainCode-Parser/DCQueryState.class.st b/packages/DomainCode-Parser/DCQueryState.class.st
index 6e6e253..587a8bf 100644
--- a/packages/DomainCode-Parser/DCQueryState.class.st
+++ b/packages/DomainCode-Parser/DCQueryState.class.st
@@ -114,9 +114,14 @@ DCQueryState >> querySourceOverride: aBlock [
 { #category : #'as yet unclassified' }
 DCQueryState >> queueUpdateQueriesFor: aSymbol [
 
-	(updateQueued at: aSymbol ifAbsent: [false]) ifTrue: [^ self].
+	(self triggers anySatisfy: [:t | updateQueued at: aSymbol ifAbsent: [false]]) ifTrue: [^ self].
+	
 	updateQueued at: aSymbol put: true.
-	rootBlock world addAlarm: #updateQueriesFor: withArguments: {aSymbol} for: self at: Time millisecondClockValue
+	rootBlock world
+		addAlarm: #updatePendingQueries
+		withArguments: {}
+		for: self
+		at: Time millisecondClockValue
 ]
 
 { #category : #'as yet unclassified' }
@@ -190,6 +195,15 @@ DCQueryState >> updateDecoratorsDuring: aBlock [
 	currentDecorators at: currentTrigger put: newDecorators
 ]
 
+{ #category : #'as yet unclassified' }
+DCQueryState >> updatePendingQueries [
+
+	updateQueued keysAndValuesDo: [:trigger :queued | queued ifTrue: [self updateQueriesFor: trigger]].
+	
+	" FIXME disallows processing to trigger another update -- intentional? "
+	self triggers do: [:t | updateQueued at: t put: false]
+]
+
 { #category : #'as yet unclassified' }
 DCQueryState >> updateQueriesFor: aSymbol [
 
diff --git a/packages/DomainCode-Parser/DCReplacement.class.st b/packages/DomainCode-Parser/DCReplacement.class.st
index d0febc9..b40bdc5 100644
--- a/packages/DomainCode-Parser/DCReplacement.class.st
+++ b/packages/DomainCode-Parser/DCReplacement.class.st
@@ -75,6 +75,13 @@ DCReplacement >> contents [
 	^ self source ifNotNil: #contents ifNil: ['']
 ]
 
+{ #category : #'as yet unclassified' }
+DCReplacement >> currentTextMorph [
+
+	self submorphsDo: [:m | m isTextMorph ifTrue: [^ m]].
+	^ nil
+]
+
 { #category : #'as yet unclassified' }
 DCReplacement >> embed: aClosure [
 
diff --git a/packages/DomainCode-Parser/DCReplacementTest.class.st b/packages/DomainCode-Parser/DCReplacementTest.class.st
index cd640bd..12f3733 100644
--- a/packages/DomainCode-Parser/DCReplacementTest.class.st
+++ b/packages/DomainCode-Parser/DCReplacementTest.class.st
@@ -176,6 +176,6 @@ DCReplacementTest >> testUninstallWithEmbeddedRoot [
 			
 			replacement := block childSandblocks first childSandblocks first.
 			self assert: DCBlock equals: replacement class.
-			self assert: #identifier equals: block children first children first type.
+			self assert: #ideantifier equals: block children first children first type.
 			self assert: 'a2' equals: block children first children first contents]
 ]
diff --git a/packages/DomainCode-Parser/DCSmalltalkMethod.class.st b/packages/DomainCode-Parser/DCSmalltalkMethod.class.st
index d9b09c4..3b01423 100644
--- a/packages/DomainCode-Parser/DCSmalltalkMethod.class.st
+++ b/packages/DomainCode-Parser/DCSmalltalkMethod.class.st
@@ -26,11 +26,11 @@ DCSmalltalkMethod class >> newWith: aString in: aClass [
 ]
 
 { #category : #'as yet unclassified' }
-DCSmalltalkMethod >> blockForPC: aNumber isActiveFrame: aBoolean [
+DCSmalltalkMethod >> blockForPC: aNumber isActiveFrame: aBoolean in: aCompiledCode [
 
 	| pc |
-	pc := aBoolean ifTrue: [aNumber] ifFalse: [self compiledMethod pcPreviousTo: aNumber].
-	(self method getSourceStringAndMark parseAsMethodFor: self methodClass) rawSourceRanges keysAndValuesDo: [:node :range | node pc = pc ifTrue: [^ self method smallestBlockEncompassig: (SBTSRange start: range start - 1 size: range size)]].
+	pc := aBoolean ifTrue: [aNumber] ifFalse: [aCompiledCode pcPreviousTo: aNumber].
+	(self method sourceString parseAsMethodFor: self methodClass) rawSourceRanges keysAndValuesDo: [:node :range | (node pc = pc or: [node pc = (aCompiledCode -> pc)]) ifTrue: [^ self method smallestBlockEncompassig: (SBTSRange start: range start - 1 size: range size)]].
 	^ nil
 ]
 
@@ -141,8 +141,12 @@ DCSmalltalkMethod >> layoutCommands [
 DCSmalltalkMethod >> messageSendForError: anError argsDo: aBlock [
 
 	| context message |
-	context := anError signalerContext findContextSuchThat: [:c | c method = self compiledMethod].
-	message := self blockForPC: context pc isActiveFrame: context = anError signalerContext.
+	context := anError signalerContext findContextSuchThat: [:c | " don't look for a block but for the home method of a block "
+	c method method = self compiledMethod].
+	message := self
+		blockForPC: context pc
+		isActiveFrame: context = anError signalerContext
+		in: context method.
 	aBlock
 		value: message
 		value: ((anError signalerContext findContextSuchThat: [:c | c sender = context]) arguments collectWithIndex: [:arg :index | (message childNodes at: 2 + (index - 1 * 2) + 1) -> arg])
@@ -230,7 +234,7 @@ DCSmalltalkMethod >> saveTryFixing: aFixBoolean quick: aQuickBoolean [
 DCSmalltalkMethod >> selector [
 
 	| selector |
-	selector := (self method queryAll: '[(unary_selector) (binary_selector) (keyword_selector)] @') ifEmpty: [^ ''] ifNotEmpty: #first.
+	selector := (self method queryFirst: {[:x | x is: #(#'unary_selector' #'binary_selector' #'keyword_selector')]}) ifNil: [^ ''].
 	
 	^ (((selector childSandblocks viewFrom: 1 by: 2) collect: [:p | p contents]) joinSeparatedBy: '') asSymbol
 ]
diff --git a/packages/DomainCode-Parser/DCSuggestionItem.class.st b/packages/DomainCode-Parser/DCSuggestionItem.class.st
index b1f3dfb..3703388 100644
--- a/packages/DomainCode-Parser/DCSuggestionItem.class.st
+++ b/packages/DomainCode-Parser/DCSuggestionItem.class.st
@@ -24,5 +24,6 @@ DCSuggestionItem >> source [
 DCSuggestionItem >> useSuggestionOn: aBlock in: anEditor [
 
 	aBlock useSuggestion: self.
-	self completionAction ifNotNil: [self completionAction cull: anEditor]
+	self completionAction ifNotNil: [self completionAction cull: anEditor].
+	aBlock batchedChangeStep
 ]
diff --git a/packages/DomainCode-Parser/DCText.class.st b/packages/DomainCode-Parser/DCText.class.st
index 4cd7eaf..08a80a6 100644
--- a/packages/DomainCode-Parser/DCText.class.st
+++ b/packages/DomainCode-Parser/DCText.class.st
@@ -21,6 +21,14 @@ DCText >> allParentsUpTo: aBlock [
 	^ {self parent}, (self parent allParentsUpTo: aBlock)
 ]
 
+{ #category : #'as yet unclassified' }
+DCText >> childrenDo: aBlock [
+]
+
+{ #category : #'as yet unclassified' }
+DCText >> clearDiffCache [
+]
+
 { #category : #'as yet unclassified' }
 DCText >> compatibleWithType: aSymbol [
 
@@ -104,6 +112,12 @@ DCText >> initialize [
 	range := SBTSRange null
 ]
 
+{ #category : #'as yet unclassified' }
+DCText >> is: aCollectionOrSymbol [
+
+	^ false
+]
+
 { #category : #'as yet unclassified' }
 DCText >> isExpression [
 
@@ -225,7 +239,12 @@ DCText >> shownColor [
 { #category : #hierarchy }
 DCText >> siblingIndex [
 
-	^ self parent children indexOf: self
+	| i |
+	i := 1.
+	self parent childrenDo: [:c |
+		c = self ifTrue: [^ i].
+		i := i + 1].
+	^ 0
 ]
 
 { #category : #'as yet unclassified' }
diff --git a/packages/Sandblocks-TreeSitter/Morph.extension.st b/packages/Sandblocks-TreeSitter/Morph.extension.st
index 4eff046..07db4c8 100644
--- a/packages/Sandblocks-TreeSitter/Morph.extension.st
+++ b/packages/Sandblocks-TreeSitter/Morph.extension.st
@@ -16,7 +16,7 @@ Morph >> containingInlineBlock [
 { #category : #'*Sandblocks-TreeSitter' }
 Morph >> descendantsPreOrder [
 
-	^ Array streamContents: [:s | self children do: [:p | p allChildrenPreorderDo: [:m | s nextPut: m]]]
+	^ Array streamContents: [:s | self childrenDo: [:p | p allChildrenPreorderDo: [:m | s nextPut: m]]]
 ]
 
 { #category : #'*Sandblocks-TreeSitter' }