Collapsing nodes (#8686)

Closes #8067

Also fixes `nodeRects` map, as it no longer stores invlisible nodes.

https://github.com/enso-org/enso/assets/6566674/ba66c99f-df74-497b-8924-dc779cce8ef5

# Important Notes
Positioning of newly created nodes is not handled yet, as it requires fixes in the Ast editing API.

app/gui2/src/components/ComponentBrowser/__tests__/placement.test.ts

@@ -1,4 +1,5 @@
 import {
+  averagePositionPlacement,
   mouseDictatedPlacement,
   nonDictatedPlacement,
   previousNodeDictatedPlacement,
@@ -447,6 +448,54 @@ describe('Mouse dictated placement', () => {
   })
 })
 
+describe('Average position placement', () => {
+  function environment(selectedNodeRects: Rect[], nonSelectedNodeRects: Rect[]): Environment {
+    return {
+      screenBounds,
+      nodeRects: [...selectedNodeRects, ...nonSelectedNodeRects],
+      selectedNodeRects,
+      get mousePosition() {
+        return getMousePosition()
+      },
+    }
+  }
+
+  function options(): { horizontalGap: number; verticalGap: number } {
+    return {
+      get horizontalGap() {
+        return getHorizontalGap()
+      },
+      get verticalGap() {
+        return getVerticalGap()
+      },
+    }
+  }
+
+  test('One selected, no other nodes', () => {
+    const X = 1100
+    const Y = 700
+    const selectedNodeRects = [rectAt(X, Y)]
+    const result = averagePositionPlacement(nodeSize, environment(selectedNodeRects, []), options())
+    expect(result).toEqual({ position: new Vec2(X, Y), pan: undefined })
+  })
+
+  test('Multiple selected, no other nodes', () => {
+    const selectedNodeRects = [rectAt(1000, 600), rectAt(1300, 800)]
+    const result = averagePositionPlacement(nodeSize, environment(selectedNodeRects, []), options())
+    expect(result).toEqual({ position: new Vec2(1150, 700), pan: undefined })
+  })
+
+  test('Average position occupied', () => {
+    const selectedNodeRects = [rectAt(1000, 600), rectAt(1300, 800)]
+    const result = averagePositionPlacement(
+      nodeSize,
+      environment(selectedNodeRects, [rectAt(1150, 700)]),
+      options(),
+    )
+    expect(result).toEqual({ position: new Vec2(1150, 744), pan: undefined })
+  })
+})
+
 // === Helpers for debugging ===
 
 function generateVueCodeForNonDictatedPlacement(newNode: Rect, rects: Rect[]) {

app/gui2/src/components/ComponentBrowser/placement.ts

@@ -128,3 +128,54 @@ export function mouseDictatedPlacement(
   const nodeRadius = nodeSize.y / 2
   return { position: mousePosition.add(new Vec2(nodeRadius, nodeRadius)) }
 }
+
+/** The new node should appear at the average position of selected nodes.
+ *
+ * If the desired place is already occupied by non-selected node, it should be moved down to the closest free space.
+ *
+ * Specifically, this code, in order:
+ * - calculates the average position of selected nodes
+ * - searches for all vertical spans below the initial position,
+ *   that horizontally intersect the initial position (no horizontal gap is required between
+ *   the new node and old nodes)
+ * - shifts the node down (if required) until there is sufficient vertical space -
+ *   the height of the node, in addition to the specified gap both above and below the node.
+ */
+export function averagePositionPlacement(
+  nodeSize: Vec2,
+  { screenBounds, selectedNodeRects, nodeRects }: Environment,
+  { verticalGap = theme.node.vertical_gap }: PlacementOptions = {},
+): Placement {
+  let totalPosition = new Vec2(0, 0)
+  let selectedNodeRectsCount = 0
+  for (const rect of selectedNodeRects) {
+    totalPosition = totalPosition.add(rect.pos)
+    selectedNodeRectsCount++
+  }
+  const initialPosition = totalPosition.scale(1.0 / selectedNodeRectsCount)
+  const nonSelectedNodeRects = []
+  outer: for (const rect of nodeRects) {
+    for (const sel of selectedNodeRects) {
+      if (sel.equals(rect)) {
+        continue outer
+      }
+    }
+    nonSelectedNodeRects.push(rect)
+  }
+  let top = initialPosition.y
+  const initialRect = new Rect(initialPosition, nodeSize)
+  const nodeRectsSorted = Array.from(nonSelectedNodeRects).sort((a, b) => a.top - b.top)
+  for (const rect of nodeRectsSorted) {
+    if (initialRect.intersectsX(rect) && rect.bottom + verticalGap > top) {
+      if (rect.top - (top + nodeSize.y) < verticalGap) {
+        top = rect.bottom + verticalGap
+      }
+    }
+  }
+  const finalPosition = new Vec2(initialPosition.x, top)
+  if (new Rect(finalPosition, nodeSize).within(screenBounds)) {
+    return { position: finalPosition }
+  } else {
+    return { position: finalPosition, pan: finalPosition.sub(initialPosition) }
+  }
+}

app/gui2/src/components/GraphEditor.vue

@@ -26,6 +26,8 @@ import { useGraphStore } from '@/stores/graph'
 import type { RequiredImport } from '@/stores/graph/imports'
 import { useProjectStore } from '@/stores/project'
 import { groupColorVar, useSuggestionDbStore } from '@/stores/suggestionDatabase'
+import { assert, bail } from '@/util/assert'
+import { BodyBlock } from '@/util/ast/abstract'
 import { colorFromString } from '@/util/colors'
 import { Rect } from '@/util/data/rect'
 import { Vec2 } from '@/util/data/vec2'
@@ -255,13 +257,23 @@ const graphBindingsHandler = graphBindings.handler({
   },
   collapse() {
     if (keyboardBusy()) return false
-    const selected = nodeSelection.selected
+    const selected = new Set(nodeSelection.selected)
     if (selected.size == 0) return
     try {
-      const info = prepareCollapsedInfo(nodeSelection.selected, graphStore.db)
+      const info = prepareCollapsedInfo(selected, graphStore.db)
-      performCollapse(info)
+      const currentMethod = projectStore.executionContext.getStackTop()
+      const currentMethodName = graphStore.db.stackItemToMethodName(currentMethod)
+      if (currentMethodName == null) {
+        bail(`Cannot get the method name for the current execution stack item. ${currentMethod}`)
+      }
+      graphStore.editAst((module) => {
+        if (graphStore.moduleRoot == null) bail(`Module root is missing.`)
+        const topLevel = module.get(graphStore.moduleRoot)
+        assert(topLevel instanceof BodyBlock)
+        return performCollapse(info, module, topLevel, graphStore.db, currentMethodName)
+      })
     } catch (err) {
-      console.log(`Error while collapsing, this is not normal. ${err}`)
+      console.log('Error while collapsing, this is not normal.', err)
     }
   },
   enterNode() {

app/gui2/src/components/GraphEditor/GraphNode.vue

@@ -20,7 +20,7 @@ import { Vec2 } from '@/util/data/vec2'
 import { displayedIconOf } from '@/util/getIconName'
 import { setIfUndefined } from 'lib0/map'
 import type { ExprId, VisualizationIdentifier } from 'shared/yjsModel'
-import { computed, ref, watch, watchEffect } from 'vue'
+import { computed, onUnmounted, ref, watch, watchEffect } from 'vue'
 
 const MAXIMUM_CLICK_LENGTH_MS = 300
 const MAXIMUM_CLICK_DISTANCE_SQ = 50
@@ -73,6 +73,8 @@ const outputPortsSet = computed(() => {
 const widthOverridePx = ref<number>()
 const nodeId = computed(() => props.node.rootSpan.exprId)
 
+onUnmounted(() => graph.unregisterNodeRect(nodeId.value))
+
 const rootNode = ref<HTMLElement>()
 const contentNode = ref<HTMLElement>()
 const nodeSize = useResizeObserver(rootNode)

app/gui2/src/components/GraphEditor/collapsing.ts

@@ -1,5 +1,6 @@
 import { GraphDb } from '@/stores/graph/graphDatabase'
 import { Ast } from '@/util/ast'
+import { moduleMethodNames } from '@/util/ast/abstract'
 import { unwrap } from '@/util/data/result'
 import { tryIdentifier, type Identifier } from '@/util/qualifiedName'
 import assert from 'assert'
@@ -40,8 +41,8 @@ interface RefactoredInfo {
   id: ExprId
   /** The pattern of the refactored node. Included for convinience, collapsing does not affect it. */
   pattern: string
-  /** The new expression of the refactored node. A call to the extracted function with the list of necessary arguments. */
+  /** The list of necessary arguments for a call of the collapsed function. */
-  expression: string
+  arguments: Identifier[]
 }
 
 // === prepareCollapsedInfo ===
@@ -55,19 +56,20 @@ export function prepareCollapsedInfo(selected: Set<ExprId>, graphDb: GraphDb): C
   const leaves = new Set([...selected])
   const inputs: Identifier[] = []
   let output: Output | null = null
-  for (const [targetExprId, sourceExprIds] of graphDb.connections.allReverse()) {
+  for (const [targetExprId, sourceExprIds] of graphDb.allConnections.allReverse()) {
     const target = graphDb.getExpressionNodeId(targetExprId)
-    if (target == null) throw new Error(`Connection target node for id ${targetExprId} not found.`)
+    if (target == null) continue
     for (const sourceExprId of sourceExprIds) {
       const source = graphDb.getPatternExpressionNodeId(sourceExprId)
-      if (source == null)
+      const startsInside = source != null && selected.has(source)
-        throw new Error(`Connection source node for id ${sourceExprId} not found.`)
-      const startsInside = selected.has(source)
       const endsInside = selected.has(target)
       const stringIdentifier = graphDb.getOutputPortIdentifier(sourceExprId)
-      if (stringIdentifier == null) throw new Error(`Source node (${source}) has no pattern.`)
+      if (stringIdentifier == null)
+        throw new Error(`Source node (${source}) has no output identifier.`)
       const identifier = unwrap(tryIdentifier(stringIdentifier))
-      leaves.delete(source)
+      if (source != null) {
+        leaves.delete(source)
+      }
       if (!startsInside && endsInside) {
         inputs.push(identifier)
       } else if (startsInside && !endsInside) {
@@ -105,21 +107,109 @@ export function prepareCollapsedInfo(selected: Set<ExprId>, graphDb: GraphDb): C
     refactored: {
       id: output.node,
       pattern,
-      expression: 'Main.collapsed' + (inputs.length > 0 ? ' ' : '') + inputs.join(' '),
+      arguments: inputs,
     },
   }
 }
 
-// === performRefactoring ===
+/** Generate a safe method name for a collapsed function using `baseName` as a prefix. */
+function findSafeMethodName(module: Ast.Module, baseName: string): string {
+  const allIdentifiers = moduleMethodNames(module)
+  if (!allIdentifiers.has(baseName)) {
+    return baseName
+  }
+  let index = 1
+  while (allIdentifiers.has(`${baseName}${index}`)) {
+    index++
+  }
+  return `${baseName}${index}`
+}
+
+// === performCollapse ===
+
+// We support working inside `Main` module of the project at the moment.
+const MODULE_NAME = 'Main'
+const COLLAPSED_FUNCTION_NAME = 'collapsed'
 
 /** Perform the actual AST refactoring for collapsing nodes. */
-export function performCollapse(_info: CollapsedInfo) {
+export function performCollapse(
-  // The general flow of this function:
+  info: CollapsedInfo,
-  // 1. Create a new function with a unique name and a list of arguments from the `ExtractedInfo`.
+  module: Ast.Module,
-  // 2. Move all nodes with `ids` from the `ExtractedInfo` into this new function. Use the order of their original definition.
+  topLevel: Ast.BodyBlock,
-  // 3. Use a single identifier `output.identifier` as the return value of the function.
+  db: GraphDb,
-  // 4. Change the expression of the `RefactoredInfo.id` node to the `RefactoredINfo.expression`
+  currentMethodName: string,
-  throw new Error('Not yet implemented, requires AST editing.')
+): Ast.MutableModule {
+  const functionAst = Ast.findModuleMethod(module, currentMethodName)
+  if (!(functionAst instanceof Ast.Function) || !(functionAst.body instanceof Ast.BodyBlock)) {
+    throw new Error(`Expected a collapsable function, found ${functionAst}.`)
+  }
+  const functionBlock = functionAst.body
+  const posToInsert = findInsertionPos(module, topLevel, currentMethodName)
+  const collapsedName = findSafeMethodName(module, COLLAPSED_FUNCTION_NAME)
+  const astIdsToExtract = new Set(
+    [...info.extracted.ids].map((nodeId) => db.nodeIdToNode.get(nodeId)?.outerExprId),
+  )
+  const astIdToReplace = db.nodeIdToNode.get(info.refactored.id)?.outerExprId
+  const collapsed = []
+  const refactored = []
+  const edit = module.edit()
+  const lines = functionBlock.lines()
+  for (const line of lines) {
+    const astId = line.expression?.node.exprId
+    const ast = astId != null ? module.get(astId) : null
+    if (ast == null) continue
+    if (astIdsToExtract.has(astId)) {
+      collapsed.push(ast)
+      if (astId === astIdToReplace) {
+        const newAst = collapsedCallAst(info, collapsedName, edit)
+        refactored.push({ expression: { node: newAst } })
+      }
+    } else {
+      refactored.push({ expression: { node: ast } })
+    }
+  }
+  const outputIdentifier = info.extracted.output?.identifier
+  if (outputIdentifier != null) {
+    collapsed.push(Ast.Ident.new(edit, outputIdentifier))
+  }
+  // Update the definiton of refactored function.
+  const refactoredBlock = Ast.BodyBlock.new(refactored, edit)
+  edit.replaceRef(functionBlock.exprId, refactoredBlock)
+  // new Ast.BodyBlock(edit, functionBlock.exprId, refactored)
+
+  const args: Ast.Ast[] = info.extracted.inputs.map((arg) => Ast.Ident.new(edit, arg))
+  const collapsedFunction = Ast.Function.new(edit, collapsedName, args, collapsed, true)
+  topLevel.insert(edit, posToInsert, collapsedFunction)
+  return edit
+}
+
+/** Prepare a method call expression for collapsed method. */
+function collapsedCallAst(
+  info: CollapsedInfo,
+  collapsedName: string,
+  edit: Ast.MutableModule,
+): Ast.Ast {
+  const pattern = info.refactored.pattern
+  const args = info.refactored.arguments
+  const functionName = `${MODULE_NAME}.${collapsedName}`
+  const expression = functionName + (args.length > 0 ? ' ' : '') + args.join(' ')
+  const assignment = Ast.Assignment.new(edit, pattern, Ast.parse(expression, edit))
+  return assignment
+}
+
+/** Find the position before the current method to insert a collapsed one. */
+function findInsertionPos(
+  module: Ast.Module,
+  topLevel: Ast.BodyBlock,
+  currentMethodName: string,
+): number {
+  const currentFuncPosition = topLevel.lines().findIndex((line) => {
+    const node = line.expression?.node
+    const expr = node ? module.get(node.exprId)?.innerExpression() : null
+    return expr instanceof Ast.Function && expr.name?.code() === currentMethodName
+  })
+
+  return currentFuncPosition === -1 ? 0 : currentFuncPosition
 }
 
 // === Tests ===
@@ -148,7 +238,7 @@ if (import.meta.vitest) {
       }
       refactored: {
         replace: string
-        with: { pattern: string; expression: string }
+        with: { pattern: string; arguments: string[] }
       }
     }
   }
@@ -166,7 +256,7 @@ if (import.meta.vitest) {
         },
         refactored: {
           replace: 'c = A + B',
-          with: { pattern: 'c', expression: 'Main.collapsed a' },
+          with: { pattern: 'c', arguments: ['a'] },
         },
       },
     },
@@ -182,7 +272,7 @@ if (import.meta.vitest) {
         },
         refactored: {
           replace: 'd = a + b',
-          with: { pattern: 'd', expression: 'Main.collapsed a b' },
+          with: { pattern: 'd', arguments: ['a', 'b'] },
         },
       },
     },
@@ -198,7 +288,7 @@ if (import.meta.vitest) {
         },
         refactored: {
           replace: 'c = 50 + d',
-          with: { pattern: 'c', expression: 'Main.collapsed' },
+          with: { pattern: 'c', arguments: [] },
         },
       },
     },
@@ -219,7 +309,7 @@ if (import.meta.vitest) {
         },
         refactored: {
           replace: 'vector = range.to_vector',
-          with: { pattern: 'vector', expression: 'Main.collapsed number1 number2' },
+          with: { pattern: 'vector', arguments: ['number1', 'number2'] },
         },
       },
     },
@@ -261,6 +351,6 @@ if (import.meta.vitest) {
     expect(extracted.ids).toEqual(new Set(expectedIds))
     expect(refactored.id).toEqual(expectedRefactoredId)
     expect(refactored.pattern).toEqual(expectedRefactored.with.pattern)
-    expect(refactored.expression).toEqual(expectedRefactored.with.expression)
+    expect(refactored.arguments).toEqual(expectedRefactored.with.arguments)
   })
 }

app/gui2/src/composables/stackNavigator.ts

@@ -30,16 +30,7 @@ export function useStackNavigator() {
   })
 
   function stackItemToLabel(item: StackItem): string {
-    switch (item.type) {
+    return graphStore.db.stackItemToMethodName(item) ?? 'unknown'
-      case 'ExplicitCall': {
-        return item.methodPointer.name
-      }
-      case 'LocalCall': {
-        const exprId = item.expressionId
-        const info = graphStore.db.getExpressionInfo(exprId)
-        return info?.methodCall?.methodPointer.name ?? 'unknown'
-      }
-    }
   }
 
   function handleBreadcrumbClick(index: number) {

app/gui2/src/stores/graph/graphDatabase.ts

@@ -12,7 +12,7 @@ import { Vec2 } from '@/util/data/vec2'
 import { ReactiveDb, ReactiveIndex, ReactiveMapping } from '@/util/database/reactiveDb'
 import * as random from 'lib0/random'
 import * as set from 'lib0/set'
-import { methodPointerEquals, type MethodCall } from 'shared/languageServerTypes'
+import { methodPointerEquals, type MethodCall, type StackItem } from 'shared/languageServerTypes'
 import {
   IdMap,
   visMetadataEquals,
@@ -137,17 +137,30 @@ export class GraphDb {
     // Display connection starting from existing node.
     //TODO[ao]: When implementing input nodes, they should be taken into account here.
     if (srcNode == null) return []
-    function* allTargets(db: GraphDb): Generator<[ExprId, ExprId]> {
+    return Array.from(this.connectionsFromBindings(info, alias, srcNode))
-      for (const usage of info.usages) {
-        const targetNode = db.getExpressionNodeId(usage)
-        // Display only connections to existing targets and different than source node
-        if (targetNode == null || targetNode === srcNode) continue
-        yield [alias, usage]
-      }
-    }
-    return Array.from(allTargets(this))
   })
 
+  /** Same as {@link GraphDb.connections}, but also includes connections without source node,
+   * e.g. input arguments of the collapsed function.
+   */
+  allConnections = new ReactiveIndex(this.bindings.bindings, (alias, info) => {
+    const srcNode = this.getPatternExpressionNodeId(alias)
+    return Array.from(this.connectionsFromBindings(info, alias, srcNode))
+  })
+
+  private *connectionsFromBindings(
+    info: BindingInfo,
+    alias: ExprId,
+    srcNode: ExprId | undefined,
+  ): Generator<[ExprId, ExprId]> {
+    for (const usage of info.usages) {
+      const targetNode = this.getExpressionNodeId(usage)
+      // Display only connections to existing targets and different than source node.
+      if (targetNode == null || targetNode === srcNode) continue
+      yield [alias, usage]
+    }
+  }
+
   /** Output port bindings of the node. Lists all bindings that can be dragged out from a node. */
   nodeOutputPorts = new ReactiveIndex(this.nodeIdToNode, (id, entry) => {
     if (entry.pattern == null) return []
@@ -206,6 +219,10 @@ export class GraphDb {
     return this.bindings.bindings.get(source)?.identifier
   }
 
+  allIdentifiers(): string[] {
+    return [...this.bindings.identifierToBindingId.allForward()].map(([ident, _]) => ident)
+  }
+
   identifierUsed(ident: string): boolean {
     return this.bindings.identifierToBindingId.hasKey(ident)
   }
@@ -249,6 +266,20 @@ export class GraphDb {
     this.nodeIdToNode.moveToLast(id)
   }
 
+  /** Get the method name from the stack item. */
+  stackItemToMethodName(item: StackItem): string | undefined {
+    switch (item.type) {
+      case 'ExplicitCall': {
+        return item.methodPointer.name
+      }
+      case 'LocalCall': {
+        const exprId = item.expressionId
+        const info = this.getExpressionInfo(exprId)
+        return info?.methodCall?.methodPointer.name
+      }
+    }
+  }
+
   readFunctionAst(functionAst_: Ast.Function, getMeta: (id: ExprId) => NodeMetadata | undefined) {
     const currentNodeIds = new Set<ExprId>()
     for (const nodeAst of functionAst_.bodyExpressions()) {

app/gui2/src/stores/graph/index.ts

@@ -63,6 +63,8 @@ export const useGraphStore = defineStore('graph', () => {
   const astModule: Module = MutableModule.Observable()
   const moduleRoot = ref<AstId>()
   let moduleDirty = false
+  const nodeRects = reactive(new Map<ExprId, Rect>())
+  const vizRects = reactive(new Map<ExprId, Rect>())
 
   // Initialize text and idmap once module is loaded (data != null)
   watch(data, () => {
@@ -78,8 +80,6 @@ export const useGraphStore = defineStore('graph', () => {
     toRef(suggestionDb, 'groups'),
     proj.computedValueRegistry,
   )
-  const nodeRects = reactive(new Map<ExprId, Rect>())
-  const vizRects = reactive(new Map<ExprId, Rect>())
   const portInstances = reactive(new Map<PortId, Set<PortViewInstance>>())
   const editedNodeInfo = ref<NodeEditInfo>()
   const imports = ref<{ import: Import; span: SourceRange }[]>([])
@@ -224,11 +224,15 @@ export const useGraphStore = defineStore('graph', () => {
     commitEdit(edit, new Map([[rhs.exprId, meta]]))
   }
 
+  function editAst(cb: (module: Ast.Module) => Ast.MutableModule) {
+    const edit = cb(astModule)
+    commitEdit(edit)
+  }
+
   function deleteNode(id: ExprId) {
     const node = db.nodeIdToNode.get(id)
     if (!node) return
     proj.module?.doc.metadata.delete(node.outerExprId)
-    nodeRects.delete(id)
     const root = moduleRoot.value
     if (!root) {
       console.error(`BUG: Cannot delete node: No module root.`)
@@ -316,6 +320,11 @@ export const useGraphStore = defineStore('graph', () => {
     else vizRects.delete(id)
   }
 
+  function unregisterNodeRect(id: ExprId) {
+    nodeRects.delete(id)
+    vizRects.delete(id)
+  }
+
   function addPortInstance(id: PortId, instance: PortViewInstance) {
     map.setIfUndefined(portInstances, id, set.create).add(instance)
   }
@@ -413,12 +422,15 @@ export const useGraphStore = defineStore('graph', () => {
     moduleCode,
     nodeRects,
     vizRects,
+    unregisterNodeRect,
     methodAst,
+    editAst,
     astModule,
     createEdgeFromOutput,
     disconnectSource,
     disconnectTarget,
     clearUnconnected,
+    moduleRoot,
     createNode,
     deleteNode,
     setNodeContent,

app/gui2/src/stores/suggestionDatabase/index.ts

@@ -1,7 +1,6 @@
 import { useProjectStore } from '@/stores/project'
 import { entryQn, type SuggestionEntry, type SuggestionId } from '@/stores/suggestionDatabase/entry'
 import { applyUpdates, entryFromLs } from '@/stores/suggestionDatabase/lsUpdate'
-import { type Opt } from '@/util/data/opt'
 import { ReactiveDb, ReactiveIndex } from '@/util/database/reactiveDb'
 import { AsyncQueue, rpcWithRetries } from '@/util/net'
 import { qnJoin, qnParent, tryQualifiedName, type QualifiedName } from '@/util/qualifiedName'

app/gui2/src/util/ast/abstract.ts

@@ -1017,6 +1017,26 @@ export class Function extends Ast {
     this.body_ = body
     setParent(module, this.exprId, ...this.concreteChildren())
   }
+
+  static new(
+    module: MutableModule,
+    name: string,
+    args: Ast[],
+    exprs: Ast[],
+    trailingNewline?: boolean,
+  ): Function {
+    const id = newAstId()
+    const exprs_: BlockLine[] = exprs.map((expr) => ({ expression: { node: expr } }))
+    if (trailingNewline) {
+      exprs_.push({ newline: { node: Token.new('\n') }, expression: null })
+    }
+    const body = BodyBlock.new(exprs_, module)
+    const args_ = args.map((arg) => [{ node: makeChild(module, arg, id) }])
+    const ident = { node: Ident.new(module, name).exprId }
+    const equals = { node: Token.new('=') }
+    return new Function(module, id, ident, args_, equals, { node: body.exprId })
+  }
+
   *concreteChildren(): IterableIterator<NodeChild> {
     yield this.name_
     for (const arg of this.args_) yield* arg
@@ -1582,6 +1602,16 @@ export function tokenTreeWithIds(root: Ast): TokenTree {
   ]
 }
 
+export function moduleMethodNames(module: Module): Set<string> {
+  const result = new Set<string>()
+  for (const node of module.raw.nodes.values()) {
+    if (node instanceof Function && node.name) {
+      result.add(node.name.code())
+    }
+  }
+  return result
+}
+
 // FIXME: We should use alias analysis to handle ambiguous names correctly.
 export function findModuleMethod(module: Module, name: string): Function | null {
   for (const node of module.raw.nodes.values()) {

app/gui2/ydoc-server/edits.ts

@@ -7,7 +7,7 @@ import diff from 'fast-diff'
 import * as json from 'lib0/json'
 import * as Y from 'yjs'
 import { TextEdit } from '../shared/languageServerTypes'
-import { IdMap, ModuleDoc, type NodeMetadata, type VisualizationMetadata } from '../shared/yjsModel'
+import { ModuleDoc, type NodeMetadata, type VisualizationMetadata } from '../shared/yjsModel'
 import * as fileFormat from './fileFormat'
 import { serializeIdMap } from './serialization'