closer

Signed-off-by: Jess Frazelle <github@jessfraz.com>

src/components/AvailableVarsHelpers.tsx

@@ -137,10 +137,10 @@ export function useCalc({
     setAvailableVarInfo(varInfo)
   }, [kclManager.ast, kclManager.programMemory, selectionRange])
 
-  useEffect(() => {
+  useEffect(async () => {
     try {
       const code = `const __result__ = ${value}`
-      const ast = parse(code)
+      parse(code).then((ast) => {
         const _programMem: any = { root: {}, return: null }
         availableVarInfo.variables.forEach(({ key, value }) => {
           _programMem.root[key] = { type: 'userVal', value, __meta: [] }
@@ -165,6 +165,7 @@ export function useCalc({
           setCalcResult(typeof result === 'number' ? String(result) : 'NAN')
           init && setValueNode(init)
         })
+      })
     } catch (e) {
       setCalcResult('NAN')
       setValueNode(null)

src/components/ModelingSidebar/ModelingPanes/MemoryPane.test.tsx

@@ -26,7 +26,7 @@ describe('processMemory', () => {
     |> lineTo([0.98, 5.16], %)
     |> lineTo([2.15, 4.32], %)
     // |> rx(90, %)`
-    const ast = parse(code)
+    const ast = await parse(code)
     const programMemory = await enginelessExecutor(ast, {
       root: {},
       return: null,

src/lang/KclSingleton.ts

@@ -43,14 +43,16 @@ export class KclManager {
     const ast = this.safeParse(code)
     if (!ast) return
     try {
+        parse(recast(ast)).then((newAst) => {
       const fmtAndStringify = (ast: Program) =>
-        JSON.stringify(parse(recast(ast)))
+        JSON.stringify(newAst)
       const isAstTheSame = fmtAndStringify(ast) === fmtAndStringify(this._ast)
       if (isAstTheSame) return
+      this.executeAst(ast)
+        })
     } catch (e) {
       console.error(e)
     }
-    this.executeAst(ast)
   }, 600)
 
   private _isExecutingCallback: (arg: boolean) => void = () => {}
@@ -143,9 +145,9 @@ export class KclManager {
     this._executeCallback = callback
   }
 
-  safeParse(code: string): Program | null {
+  async safeParse(code: string): Promise<Program | null> {
     try {
-      const ast = parse(code)
+      const ast = await parse(code)
       this.kclErrors = []
       return ast
     } catch (e) {

src/lang/abstractSyntaxTree.test.ts

@@ -4,8 +4,8 @@ import { initPromise, parse } from './wasm'
 beforeAll(() => initPromise)
 
 describe('testing AST', () => {
-  test('5 + 6', () => {
-    const result = parse('5 +6')
+  test('5 + 6', async () => {
+    const result = await parse('5 +6')
     delete (result as any).nonCodeMeta
     expect(result.body).toEqual([
       {
@@ -35,8 +35,8 @@ describe('testing AST', () => {
       },
     ])
   })
-  test('const myVar = 5', () => {
-    const { body } = parse('const myVar = 5')
+  test('const myVar = 5', async () => {
+    const { body } = await parse('const myVar = 5')
     expect(body).toEqual([
       {
         type: 'VariableDeclaration',
@@ -66,11 +66,11 @@ describe('testing AST', () => {
       },
     ])
   })
-  test('multi-line', () => {
+  test('multi-line', async () => {
     const code = `const myVar = 5
 const newVar = myVar + 1
 `
-    const { body } = parse(code)
+    const { body } = await parse(code)
     expect(body).toEqual([
       {
         type: 'VariableDeclaration',
@@ -141,8 +141,8 @@ const newVar = myVar + 1
 })
 
 describe('testing function declaration', () => {
-  test('fn funcN = (a, b) => {return a + b}', () => {
-    const { body } = parse(
+  test('fn funcN = (a, b) => {return a + b}', async () => {
+    const { body } = await parse(
       ['fn funcN = (a, b) => {', '  return a + b', '}'].join('\n')
     )
     delete (body[0] as any).declarations[0].init.body.nonCodeMeta
@@ -224,10 +224,10 @@ describe('testing function declaration', () => {
       },
     ])
   })
-  test('call expression assignment', () => {
+  test('call expression assignment', async () => {
     const code = `fn funcN = (a, b) => { return a + b }
 const myVar = funcN(1, 2)`
-    const { body } = parse(code)
+    const { body } = await parse(code)
     delete (body[0] as any).declarations[0].init.body.nonCodeMeta
     expect(body).toEqual([
       {
@@ -357,14 +357,14 @@ const myVar = funcN(1, 2)`
 })
 
 describe('testing pipe operator special', () => {
-  test('pipe operator with sketch', () => {
+  test('pipe operator with sketch', async () => {
     let code = `const mySketch = startSketchAt([0, 0])
   |> lineTo([2, 3], %)
   |> lineTo([0, 1], %, "myPath")
   |> lineTo([1, 1], %)
   |> rx(45, %)
 `
-    const { body } = parse(code)
+    const { body } = await parse(code)
     delete (body[0] as any).declarations[0].init.nonCodeMeta
     expect(body).toEqual([
       {
@@ -562,9 +562,9 @@ describe('testing pipe operator special', () => {
       },
     ])
   })
-  test('pipe operator with binary expression', () => {
+  test('pipe operator with binary expression', async () => {
     let code = `const myVar = 5 + 6 |> myFunc(45, %)`
-    const { body } = parse(code)
+    const { body } = await parse(code)
     delete (body as any)[0].declarations[0].init.nonCodeMeta
     expect(body).toEqual([
       {
@@ -641,9 +641,9 @@ describe('testing pipe operator special', () => {
       },
     ])
   })
-  test('array expression', () => {
+  test('array expression', async () => {
     let code = `const yo = [1, '2', three, 4 + 5]`
-    const { body } = parse(code)
+    const { body } = await parse(code)
     expect(body).toEqual([
       {
         type: 'VariableDeclaration',
@@ -713,12 +713,12 @@ describe('testing pipe operator special', () => {
       },
     ])
   })
-  test('object expression ast', () => {
+  test('object expression ast', async () => {
     const code = [
       'const three = 3',
       "const yo = {aStr: 'str', anum: 2, identifier: three, binExp: 4 + 5}",
     ].join('\n')
-    const { body } = parse(code)
+    const { body } = await parse(code)
     expect(body).toEqual([
       {
         type: 'VariableDeclaration',
@@ -858,11 +858,11 @@ describe('testing pipe operator special', () => {
       },
     ])
   })
-  test('nested object expression ast', () => {
+  test('nested object expression ast', async () => {
     const code = `const yo = {key: {
   key2: 'value'
 }}`
-    const { body } = parse(code)
+    const { body } = await parse(code)
     expect(body).toEqual([
       {
         type: 'VariableDeclaration',
@@ -928,9 +928,9 @@ describe('testing pipe operator special', () => {
       },
     ])
   })
-  test('object expression with array ast', () => {
+  test('object expression with array ast', async () => {
     const code = `const yo = {key: [1, '2']}`
-    const { body } = parse(code)
+    const { body } = await parse(code)
     expect(body).toEqual([
       {
         type: 'VariableDeclaration',
@@ -992,9 +992,9 @@ describe('testing pipe operator special', () => {
       },
     ])
   })
-  test('object memberExpression simple', () => {
+  test('object memberExpression simple', async () => {
     const code = `const prop = yo.one.two`
-    const { body } = parse(code)
+    const { body } = await parse(code)
     expect(body).toEqual([
       {
         type: 'VariableDeclaration',
@@ -1047,9 +1047,9 @@ describe('testing pipe operator special', () => {
       },
     ])
   })
-  test('object memberExpression with square braces', () => {
+  test('object memberExpression with square braces', async () => {
     const code = `const prop = yo.one["two"]`
-    const { body } = parse(code)
+    const { body } = await parse(code)
     expect(body).toEqual([
       {
         type: 'VariableDeclaration',
@@ -1103,9 +1103,9 @@ describe('testing pipe operator special', () => {
       },
     ])
   })
-  test('object memberExpression with two square braces literal and identifier', () => {
+  test('object memberExpression with two square braces literal and identifier', async () => {
     const code = `const prop = yo["one"][two]`
-    const { body } = parse(code)
+    const { body } = await parse(code)
     expect(body).toEqual([
       {
         type: 'VariableDeclaration',
@@ -1162,9 +1162,9 @@ describe('testing pipe operator special', () => {
 })
 
 describe('nests binary expressions correctly', () => {
-  it('works with the simple case', () => {
+  it('works with the simple case', async () => {
     const code = `const yo = 1 + 2`
-    const { body } = parse(code)
+    const { body } = await parse(code)
     expect(body[0]).toEqual({
       type: 'VariableDeclaration',
       start: 0,
@@ -1205,10 +1205,10 @@ describe('nests binary expressions correctly', () => {
       ],
     })
   })
-  it('should nest according to precedence with multiply first', () => {
+  it('should nest according to precedence with multiply first', async () => {
     // should be binExp { binExp { lit-1 * lit-2 } + lit}
     const code = `const yo = 1 * 2 + 3`
-    const { body } = parse(code)
+    const { body } = await parse(code)
     expect(body[0]).toEqual({
       type: 'VariableDeclaration',
       start: 0,
@@ -1262,10 +1262,10 @@ describe('nests binary expressions correctly', () => {
       ],
     })
   })
-  it('should nest according to precedence with sum first', () => {
+  it('should nest according to precedence with sum first', async () => {
     // should be binExp { lit-1 + binExp { lit-2 * lit-3 } }
     const code = `const yo = 1 + 2 * 3`
-    const { body } = parse(code)
+    const { body } = await parse(code)
     expect(body[0]).toEqual({
       type: 'VariableDeclaration',
       start: 0,
@@ -1319,9 +1319,9 @@ describe('nests binary expressions correctly', () => {
       ],
     })
   })
-  it('should nest properly with two operators of equal precedence', () => {
+  it('should nest properly with two operators of equal precedence', async () => {
     const code = `const yo = 1 + 2 - 3`
-    const { body } = parse(code)
+    const { body } = await parse(code)
     expect((body[0] as any).declarations[0].init).toEqual({
       type: 'BinaryExpression',
       start: 11,
@@ -1356,9 +1356,9 @@ describe('nests binary expressions correctly', () => {
       },
     })
   })
-  it('should nest properly with two operators of equal (but higher) precedence', () => {
+  it('should nest properly with two operators of equal (but higher) precedence', async () => {
     const code = `const yo = 1 * 2 / 3`
-    const { body } = parse(code)
+    const { body } = await parse(code)
     expect((body[0] as any).declarations[0].init).toEqual({
       type: 'BinaryExpression',
       start: 11,
@@ -1393,9 +1393,9 @@ describe('nests binary expressions correctly', () => {
       },
     })
   })
-  it('should nest properly with longer example', () => {
+  it('should nest properly with longer example', async () => {
     const code = `const yo = 1 + 2 * (3 - 4) / 5 + 6`
-    const { body } = parse(code)
+    const { body } = await parse(code)
     const init = (body[0] as any).declarations[0].init
     expect(init).toEqual({
       type: 'BinaryExpression',
@@ -1443,7 +1443,7 @@ describe('nests binary expressions correctly', () => {
 })
 
 describe('check nonCodeMeta data is attached to the AST correctly', () => {
-  it('comments between expressions', () => {
+  it('comments between expressions', async () => {
     const code = `
 const yo = { a: { b: { c: '123' } } }
 // this is a comment
@@ -1458,12 +1458,14 @@ const key = 'c'`
         value: 'this is a comment',
       },
     }
-    const { nonCodeMeta } = parse(code)
+    const { nonCodeMeta } = await parse(code)
     expect(nonCodeMeta.nonCodeNodes[0][0]).toEqual(nonCodeMetaInstance)
 
     // extra whitespace won't change it's position (0) or value (NB the start end would have changed though)
     const codeWithExtraStartWhitespace = '\n\n\n' + code
-    const { nonCodeMeta: nonCodeMeta2 } = parse(codeWithExtraStartWhitespace)
+    const { nonCodeMeta: nonCodeMeta2 } = await parse(
+      codeWithExtraStartWhitespace
+    )
     expect(nonCodeMeta2.nonCodeNodes[0][0].value).toStrictEqual(
       nonCodeMetaInstance.value
     )
@@ -1471,7 +1473,7 @@ const key = 'c'`
       nonCodeMetaInstance.start
     )
   })
-  it('comments nested within a block statement', () => {
+  it('comments nested within a block statement', async () => {
     const code = `const mySketch = startSketchAt([0,0])
   |> lineTo([0, 1], %, 'myPath')
   |> lineTo([1, 1], %) /* this is
@@ -1481,7 +1483,7 @@ const key = 'c'`
   |> close(%)
 `
 
-    const { body } = parse(code)
+    const { body } = await parse(code)
     const indexOfSecondLineToExpression = 2
     const sketchNonCodeMeta = (body as any)[0].declarations[0].init.nonCodeMeta
       .nonCodeNodes
@@ -1496,7 +1498,7 @@ const key = 'c'`
       },
     })
   })
-  it('comments in a pipe expression', () => {
+  it('comments in a pipe expression', async () => {
     const code = [
       'const mySk1 = startSketchAt([0, 0])',
       '  |> lineTo([1, 1], %)',
@@ -1506,7 +1508,7 @@ const key = 'c'`
       '  |> rx(90, %)',
     ].join('\n')
 
-    const { body } = parse(code)
+    const { body } = await parse(code)
     const sketchNonCodeMeta = (body[0] as any).declarations[0].init.nonCodeMeta
       .nonCodeNodes[3][0]
     expect(sketchNonCodeMeta).toEqual({
@@ -1523,9 +1525,9 @@ const key = 'c'`
 })
 
 describe('test UnaryExpression', () => {
-  it('should parse a unary expression in simple var dec situation', () => {
+  it('should parse a unary expression in simple var dec situation', async () => {
     const code = `const myVar = -min(4, 100)`
-    const { body } = parse(code)
+    const { body } = await parse(code)
     const myVarInit = (body?.[0] as any).declarations[0]?.init
     expect(myVarInit).toEqual({
       type: 'UnaryExpression',
@@ -1548,9 +1550,9 @@ describe('test UnaryExpression', () => {
 })
 
 describe('testing nested call expressions', () => {
-  it('callExp in a binExp in a callExp', () => {
+  it('callExp in a binExp in a callExp', async () => {
     const code = 'const myVar = min(100, 1 + legLen(5, 3))'
-    const { body } = parse(code)
+    const { body } = await parse(code)
     const myVarInit = (body?.[0] as any).declarations[0]?.init
     expect(myVarInit).toEqual({
       type: 'CallExpression',
@@ -1585,8 +1587,8 @@ describe('testing nested call expressions', () => {
 
 describe('should recognise callExpresions in binaryExpressions', () => {
   const code = "xLineTo(segEndX('seg02', %) + 1, %)"
-  it('should recognise the callExp', () => {
-    const { body } = parse(code)
+  it('should recognise the callExp', async () => {
+    const { body } = await parse(code)
     const callExpArgs = (body?.[0] as any).expression?.arguments
     expect(callExpArgs).toEqual([
       {

src/lang/artifact.test.ts

@@ -12,7 +12,7 @@ const mySketch001 = startSketchOn('XY')
   |> lineTo([-1.59, -1.54], %)
   |> lineTo([0.46, -5.82], %)
   // |> rx(45, %)`
-    const programMemory = await enginelessExecutor(parse(code))
+    const programMemory = await enginelessExecutor(await parse(code))
     // @ts-ignore
     const sketch001 = programMemory?.root?.mySketch001
     expect(sketch001).toEqual({
@@ -68,7 +68,7 @@ const mySketch001 = startSketchOn('XY')
   |> lineTo([0.46, -5.82], %)
   // |> rx(45, %)
   |> extrude(2, %)`
-    const programMemory = await enginelessExecutor(parse(code))
+    const programMemory = await enginelessExecutor(await parse(code))
     // @ts-ignore
     const sketch001 = programMemory?.root?.mySketch001
     expect(sketch001).toEqual({
@@ -150,7 +150,7 @@ const sk2 = startSketchOn('XY')
   |> extrude(2, %)
 
 `
-    const programMemory = await enginelessExecutor(parse(code))
+    const programMemory = await enginelessExecutor(await parse(code))
     // @ts-ignore
     const geos = [programMemory?.root?.theExtrude, programMemory?.root?.sk2]
     expect(geos).toEqual([

src/lang/executor.test.ts

@@ -398,7 +398,7 @@ async function exe(
   code: string,
   programMemory: ProgramMemory = { root: {}, return: null }
 ) {
-  const ast = parse(code)
+  const ast = await parse(code)
 
   const result = await enginelessExecutor(ast, programMemory)
   return result

src/lang/getNodePathFromSourceRange.test.ts

@@ -4,7 +4,7 @@ import { Identifier, parse, initPromise, Parameter } from './wasm'
 beforeAll(() => initPromise)
 
 describe('testing getNodePathFromSourceRange', () => {
-  it('test it gets the right path for a `lineTo` CallExpression within a SketchExpression', () => {
+  it('test it gets the right path for a `lineTo` CallExpression within a SketchExpression', async () => {
     const code = `
 const myVar = 5
 const sk3 = startSketchAt([0, 0])
@@ -19,14 +19,14 @@ const sk3 = startSketchAt([0, 0])
       lineToSubstringIndex + subStr.length,
     ]
 
-    const ast = parse(code)
+    const ast = await parse(code)
     const nodePath = getNodePathFromSourceRange(ast, sourceRange)
     const { node } = getNodeFromPath<any>(ast, nodePath)
 
     expect([node.start, node.end]).toEqual(sourceRange)
     expect(node.type).toBe('CallExpression')
   })
-  it('gets path right for function definition params', () => {
+  it('gets path right for function definition params', async () => {
     const code = `fn cube = (pos, scale) => {
   const sg = startSketchAt(pos)
     |> line([0, scale], %)
@@ -44,7 +44,7 @@ const b1 = cube([0,0], 10)`
       subStrIndex + 'pos'.length,
     ]
 
-    const ast = parse(code)
+    const ast = await parse(code)
     const nodePath = getNodePathFromSourceRange(ast, sourceRange)
     const node = getNodeFromPath<Parameter>(ast, nodePath).node
 
@@ -60,7 +60,7 @@ const b1 = cube([0,0], 10)`
     expect(node.type).toBe('Parameter')
     expect(node.identifier.name).toBe('pos')
   })
-  it('gets path right for deep within function definition body', () => {
+  it('gets path right for deep within function definition body', async () => {
     const code = `fn cube = (pos, scale) => {
   const sg = startSketchAt(pos)
     |> line([0, scale], %)
@@ -78,7 +78,7 @@ const b1 = cube([0,0], 10)`
       subStrIndex + 'scale'.length,
     ]
 
-    const ast = parse(code)
+    const ast = await parse(code)
     const nodePath = getNodePathFromSourceRange(ast, sourceRange)
     const node = getNodeFromPath<Identifier>(ast, nodePath).node
     expect(nodePath).toEqual([

src/lang/parser.ts

@@ -0,0 +1,81 @@
+import {
+  ParserWorkerResponse,
+  WasmWorker,
+  WasmWorkerEventType,
+  ParserWorkerCallResponse,
+} from 'lang/workers/types'
+import Worker from 'lang/workers/parser?worker'
+import { Program, wasmUrl } from 'lang/wasm'
+import { KCLError } from 'lang/errors'
+import { v4 as uuidv4 } from 'uuid'
+
+export default class Parser {
+  worker: any = new Worker({ name: 'parse' })
+  intitalized: boolean = false
+  mappings: Map<string, Program | KCLError> = new Map()
+
+  async parse(code: string): Promise<Program> {
+    this.ensureWorker()
+    const uuid = uuidv4()
+    this.worker.postMessage({
+      worker: WasmWorker.Parser,
+      eventType: WasmWorkerEventType.Call,
+      eventData: {
+        uuid,
+        code,
+      },
+    })
+    let result = await this.waitForResult(uuid)
+    if (result instanceof KCLError) {
+      throw result
+    }
+    return result
+  }
+
+  waitForResult(uuid: string): Promise<Program | KCLError> {
+    return new Promise((resolve) => {
+      const result = this.mappings.get(uuid)
+      if (result) {
+        this.mappings.delete(uuid)
+        resolve(result)
+      } else {
+        setTimeout(() => {
+          resolve(this.waitForResult(uuid))
+        }, 100)
+      }
+    })
+  }
+
+  ensureWorker() {
+    if (!this.intitalized) {
+      this.start()
+    }
+  }
+
+  // Start the worker.
+  start() {
+    if (this.intitalized) {
+      console.log('Worker already initialized')
+      return
+    }
+    this.worker.postMessage({
+      worker: WasmWorker.Parser,
+      eventType: WasmWorkerEventType.Init,
+      eventData: {
+        wasmUrl: wasmUrl(),
+      },
+    })
+
+    this.worker.onmessage = function (r: ParserWorkerResponse) {
+      switch (r.eventType) {
+        case WasmWorkerEventType.Init:
+          this.intitalized = true
+          break
+        case WasmWorkerEventType.Call:
+          const c = r.response as ParserWorkerCallResponse
+          this.mappings.set(c.uuid, c.response)
+          break
+      }
+    }
+  }
+}

src/lang/recast.test.ts

@@ -4,53 +4,53 @@ import fs from 'node:fs'
 beforeAll(() => initPromise)
 
 describe('recast', () => {
-  it('recasts a simple program', () => {
+  it('recasts a simple program', async () => {
     const code = '1 + 2'
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code)
   })
-  it('variable declaration', () => {
+  it('variable declaration', async () => {
     const code = 'const myVar = 5'
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code)
   })
-  it("variable declaration that's binary with string", () => {
+  it("variable declaration that's binary with string", async () => {
     const code = "const myVar = 5 + 'yo'"
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code)
     const codeWithOtherQuotes = 'const myVar = 5 + "yo"'
-    const { ast: ast2 } = code2ast(codeWithOtherQuotes)
+    const { ast: ast2 } = await code2ast(codeWithOtherQuotes)
     expect(recast(ast2).trim()).toBe(codeWithOtherQuotes)
   })
-  it('test assigning two variables, the second summing with the first', () => {
+  it('test assigning two variables, the second summing with the first', async () => {
     const code = `const myVar = 5
 const newVar = myVar + 1
 `
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted).toBe(code)
   })
-  it('test assigning a var by cont concatenating two strings string', () => {
+  it('test assigning a var by cont concatenating two strings string', async () => {
     const code = fs.readFileSync(
       './src/lang/testExamples/variableDeclaration.cado',
       'utf-8'
     )
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code.trim())
   })
-  it('test with function call', () => {
+  it('test with function call', async () => {
     const code = `const myVar = "hello"
 log(5, myVar)
 `
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted).toBe(code)
   })
-  it('function declaration with call', () => {
+  it('function declaration with call', async () => {
     const code = [
       'fn funcN = (a, b) => {',
       '  return a + b',
@@ -58,22 +58,22 @@ log(5, myVar)
       'const theVar = 60',
       'const magicNum = funcN(9, theVar)',
     ].join('\n')
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code)
   })
-  it('recast sketch declaration', () => {
+  it('recast sketch declaration', async () => {
     let code = `const mySketch = startSketchAt([0, 0])
   |> lineTo([0, 1], %, "myPath")
   |> lineTo([1, 1], %)
   |> lineTo([1, 0], %, "rightPath")
   |> close(%)
 `
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted).toBe(code)
   })
-  it('sketch piped into callExpression', () => {
+  it('sketch piped into callExpression', async () => {
     const code = [
       'const mySk1 = startSketchAt([0, 0])',
       '  |> lineTo([1, 1], %)',
@@ -81,11 +81,11 @@ log(5, myVar)
       '  |> lineTo([1, 1], %)',
       '  |> rx(90, %)',
     ].join('\n')
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code.trim())
   })
-  it('recast BinaryExpression piped into CallExpression', () => {
+  it('recast BinaryExpression piped into CallExpression', async () => {
     const code = [
       'fn myFn = (a) => {',
       '  return a + 1',
@@ -93,49 +93,49 @@ log(5, myVar)
       'const myVar = 5 + 1',
       '  |> myFn(%)',
     ].join('\n')
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code)
   })
-  it('recast nested binary expression', () => {
+  it('recast nested binary expression', async () => {
     const code = ['const myVar = 1 + 2 * 5'].join('\n')
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code.trim())
   })
-  it('recast nested binary expression with parans', () => {
+  it('recast nested binary expression with parans', async () => {
     const code = ['const myVar = 1 + (1 + 2) * 5'].join('\n')
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code.trim())
   })
-  it('unnecessary paran wrap will be remove', () => {
+  it('unnecessary paran wrap will be remove', async () => {
     const code = ['const myVar = 1 + (2 * 5)'].join('\n')
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code.replace('(', '').replace(')', ''))
   })
-  it('complex nested binary expression', () => {
+  it('complex nested binary expression', async () => {
     const code = ['1 * ((2 + 3) / 4 + 5)'].join('\n')
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code.trim())
   })
-  it('multiplied paren expressions', () => {
+  it('multiplied paren expressions', async () => {
     const code = ['3 + (1 + 2) * (3 + 4)'].join('\n')
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code.trim())
   })
-  it('recast array declaration', () => {
+  it('recast array declaration', async () => {
     const code = ['const three = 3', "const yo = [1, '2', three, 4 + 5]"].join(
       '\n'
     )
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code.trim())
   })
-  it('recast long array declaration', () => {
+  it('recast long array declaration', async () => {
     const code = [
       'const three = 3',
       'const yo = [',
@@ -146,11 +146,11 @@ log(5, myVar)
       "  'hey oooooo really long long long'",
       ']',
     ].join('\n')
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code.trim())
   })
-  it('recast long object execution', () => {
+  it('recast long object execution', async () => {
     const code = `const three = 3
 const yo = {
   aStr: 'str',
@@ -159,43 +159,43 @@ const yo = {
   binExp: 4 + 5
 }
 `
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted).toBe(code)
   })
-  it('recast short object execution', () => {
+  it('recast short object execution', async () => {
     const code = `const yo = { key: 'val' }
 `
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted).toBe(code)
   })
-  it('recast object execution with member expression', () => {
+  it('recast object execution with member expression', async () => {
     const code = `const yo = { a: { b: { c: '123' } } }
 const key = 'c'
 const myVar = yo.a['b'][key]
 const key2 = 'b'
 const myVar2 = yo['a'][key2].c
 `
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted).toBe(code)
   })
 })
 
 describe('testing recasting with comments and whitespace', () => {
-  it('code with comments', () => {
+  it('code with comments', async () => {
     const code = `const yo = { a: { b: { c: '123' } } }
 // this is a comment
 const key = 'c'
 `
 
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
 
     expect(recasted).toBe(code)
   })
-  it('code with comment and extra lines', () => {
+  it('code with comment and extra lines', async () => {
     const code = `const yo = 'c'
 
 /* this is
@@ -203,23 +203,23 @@ a
 comment */
 const yo = 'bing'
 `
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted).toBe(code)
   })
-  it('comments at the start and end', () => {
+  it('comments at the start and end', async () => {
     const code = `// this is a comment
 const yo = { a: { b: { c: '123' } } }
 const key = 'c'
 
 // this is also a comment
 `
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted).toBe(code)
   })
-  it('comments in a fn block', () => {
-    const code = `fn myFn = () => {
+  it('comments in a fn block', async () => {
+    const code = `fn myFn = async () => {
   // this is a comment
   const yo = { a: { b: { c: '123' } } }
 
@@ -229,11 +229,11 @@ const key = 'c'
   // this is also a comment
 }
 `
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted).toBe(code)
   })
-  it('comments in a pipe expression', () => {
+  it('comments in a pipe expression', async () => {
     const code = [
       'const mySk1 = startSketchAt([0, 0])',
       '  |> lineTo([1, 1], %)',
@@ -242,11 +242,11 @@ const key = 'c'
       '  // a comment',
       '  |> rx(90, %)',
     ].join('\n')
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code)
   })
-  it('comments sprinkled in all over the place', () => {
+  it('comments sprinkled in all over the place', async () => {
     const code = `
 /* comment at start */
 
@@ -268,7 +268,7 @@ const mySk1 = startSketchAt([0, 0])
   one more for good measure
   */
 `
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted).toBe(`/* comment at start */
 
@@ -289,37 +289,37 @@ const mySk1 = startSketchAt([0, 0])
 })
 
 describe('testing call Expressions in BinaryExpressions and UnaryExpressions', () => {
-  it('nested callExpression in binaryExpression', () => {
+  it('nested callExpression in binaryExpression', async () => {
     const code = 'const myVar = 2 + min(100, legLen(5, 3))'
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code)
   })
-  it('nested callExpression in unaryExpression', () => {
+  it('nested callExpression in unaryExpression', async () => {
     const code = 'const myVar = -min(100, legLen(5, 3))'
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code)
   })
-  it('with unaryExpression in callExpression', () => {
+  it('with unaryExpression in callExpression', async () => {
     const code = 'const myVar = min(5, -legLen(5, 4))'
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code)
   })
-  it('with unaryExpression in sketch situation', () => {
+  it('with unaryExpression in sketch situation', async () => {
     const code = [
       'const part001 = startSketchAt([0, 0])',
       '  |> line([-2.21, -legLen(5, min(3, 999))], %)',
     ].join('\n')
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted.trim()).toBe(code)
   })
 })
 
 describe('it recasts wrapped object expressions in pipe bodies with correct indentation', () => {
-  it('with a single line', () => {
+  it('with a single line', async () => {
     const code = `const part001 = startSketchAt([-0.01, -0.08])
   |> line([0.62, 4.15], %, 'seg01')
   |> line([2.77, -1.24], %)
@@ -330,35 +330,35 @@ describe('it recasts wrapped object expressions in pipe bodies with correct inde
      }, %)
   |> line([-0.42, -1.72], %)
 `
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted).toBe(code)
   })
-  it('recasts wrapped object expressions NOT in pipe body correctly', () => {
+  it('recasts wrapped object expressions NOT in pipe body correctly', async () => {
     const code = `angledLineThatIntersects({
   angle: 201,
   offset: -1.35,
   intersectTag: 'seg01'
 }, %)
 `
-    const { ast } = code2ast(code)
+    const { ast } = await code2ast(code)
     const recasted = recast(ast)
     expect(recasted).toBe(code)
   })
 })
 
 describe('it recasts binary expression using brackets where needed', () => {
-  it('when there are two minus in a row', () => {
+  it('when there are two minus in a row', async () => {
     const code = `const part001 = 1 - (def - abc)
 `
-    const recasted = recast(code2ast(code).ast)
+    const recasted = recast((await code2ast(code)).ast)
     expect(recasted).toBe(code)
   })
 })
 
 // helpers
 
-function code2ast(code: string): { ast: Program } {
-  const ast = parse(code)
+async function code2ast(code: string): Promise<{ ast: Program }> {
+  const ast = await parse(code)
   return { ast }
 }

src/lang/std/sketch.test.ts

@@ -104,7 +104,7 @@ describe('testing changeSketchArguments', () => {
 `
     const code = genCode(lineToChange)
     const expectedCode = genCode(lineAfterChange)
-    const ast = parse(code)
+    const ast = await parse(code)
     const programMemory = await enginelessExecutor(ast)
     const sourceStart = code.indexOf(lineToChange)
     const { modifiedAst } = changeSketchArguments(
@@ -128,7 +128,7 @@ const mySketch001 = startSketchOn('XY')
   // |> rx(45, %)
   |> lineTo([-1.59, -1.54], %)
   |> lineTo([0.46, -5.82], %)`
-    const ast = parse(code)
+    const ast = await parse(code)
     const programMemory = await enginelessExecutor(ast)
     const sourceStart = code.indexOf(lineToChange)
     expect(sourceStart).toBe(95)
@@ -190,7 +190,7 @@ describe('testing addTagForSketchOnFace', () => {
   |> lineTo([0.46, -5.82], %)
 `
     const code = genCode(originalLine)
-    const ast = parse(code)
+    const ast = await parse(code)
     const programMemory = await enginelessExecutor(ast)
     const sourceStart = code.indexOf(originalLine)
     const sourceRange: [number, number] = [

src/lang/std/sketchConstraints.test.ts

@@ -28,7 +28,7 @@ async function testingSwapSketchFnCall({
     type: 'default',
     range: [startIndex, startIndex + callToSwap.length],
   }
-  const ast = parse(inputCode)
+  const ast = await parse(inputCode)
   const programMemory = await enginelessExecutor(ast)
   const selections = {
     codeBasedSelections: [range],
@@ -351,7 +351,7 @@ const part001 = startSketchOn('XY')
   |> line([2.14, 1.35], %) // normal-segment
   |> xLine(3.54, %)`
   it('normal case works', async () => {
-    const programMemory = await enginelessExecutor(parse(code))
+    const programMemory = await enginelessExecutor(await parse(code))
     const index = code.indexOf('// normal-segment') - 7
     const { __geoMeta, ...segment } = getSketchSegmentFromSourceRange(
       programMemory.root['part001'] as SketchGroup,
@@ -365,7 +365,7 @@ const part001 = startSketchOn('XY')
     })
   })
   it('verify it works when the segment is in the `start` property', async () => {
-    const programMemory = await enginelessExecutor(parse(code))
+    const programMemory = await enginelessExecutor(await parse(code))
     const index = code.indexOf('// segment-in-start') - 7
     const { __geoMeta, ...segment } = getSketchSegmentFromSourceRange(
       programMemory.root['part001'] as SketchGroup,

src/lang/std/sketchcombos.test.ts

@@ -15,53 +15,53 @@ beforeAll(() => initPromise)
 
 describe('testing getConstraintType', () => {
   const helper = getConstraintTypeFromSourceHelper
-  it('testing line', () => {
-    expect(helper(`line([5, myVar], %)`)).toBe('yRelative')
-    expect(helper(`line([myVar, 5], %)`)).toBe('xRelative')
+  it('testing line', async () => {
+    expect(await helper(`line([5, myVar], %)`)).toBe('yRelative')
+    expect(await helper(`line([myVar, 5], %)`)).toBe('xRelative')
   })
-  it('testing lineTo', () => {
-    expect(helper(`lineTo([5, myVar], %)`)).toBe('yAbsolute')
-    expect(helper(`lineTo([myVar, 5], %)`)).toBe('xAbsolute')
+  it('testing lineTo', async () => {
+    expect(await helper(`lineTo([5, myVar], %)`)).toBe('yAbsolute')
+    expect(await helper(`lineTo([myVar, 5], %)`)).toBe('xAbsolute')
   })
-  it('testing angledLine', () => {
-    expect(helper(`angledLine([5, myVar], %)`)).toBe('length')
-    expect(helper(`angledLine([myVar, 5], %)`)).toBe('angle')
+  it('testing angledLine', async () => {
+    expect(await helper(`angledLine([5, myVar], %)`)).toBe('length')
+    expect(await helper(`angledLine([myVar, 5], %)`)).toBe('angle')
   })
-  it('testing angledLineOfXLength', () => {
-    expect(helper(`angledLineOfXLength([5, myVar], %)`)).toBe('xRelative')
-    expect(helper(`angledLineOfXLength([myVar, 5], %)`)).toBe('angle')
+  it('testing angledLineOfXLength', async () => {
+    expect(await helper(`angledLineOfXLength([5, myVar], %)`)).toBe('xRelative')
+    expect(await helper(`angledLineOfXLength([myVar, 5], %)`)).toBe('angle')
   })
-  it('testing angledLineToX', () => {
-    expect(helper(`angledLineToX([5, myVar], %)`)).toBe('xAbsolute')
-    expect(helper(`angledLineToX([myVar, 5], %)`)).toBe('angle')
+  it('testing angledLineToX', async () => {
+    expect(await helper(`angledLineToX([5, myVar], %)`)).toBe('xAbsolute')
+    expect(await helper(`angledLineToX([myVar, 5], %)`)).toBe('angle')
   })
-  it('testing angledLineOfYLength', () => {
-    expect(helper(`angledLineOfYLength([5, myVar], %)`)).toBe('yRelative')
-    expect(helper(`angledLineOfYLength([myVar, 5], %)`)).toBe('angle')
+  it('testing angledLineOfYLength', async () => {
+    expect(await helper(`angledLineOfYLength([5, myVar], %)`)).toBe('yRelative')
+    expect(await helper(`angledLineOfYLength([myVar, 5], %)`)).toBe('angle')
   })
-  it('testing angledLineToY', () => {
-    expect(helper(`angledLineToY([5, myVar], %)`)).toBe('yAbsolute')
-    expect(helper(`angledLineToY([myVar, 5], %)`)).toBe('angle')
+  it('testing angledLineToY', async () => {
+    expect(await helper(`angledLineToY([5, myVar], %)`)).toBe('yAbsolute')
+    expect(await helper(`angledLineToY([myVar, 5], %)`)).toBe('angle')
   })
   const helper2 = getConstraintTypeFromSourceHelper2
-  it('testing xLine', () => {
-    expect(helper2(`xLine(5, %)`)).toBe('yRelative')
+  it('testing xLine', async () => {
+    expect(await helper2(`xLine(5, %)`)).toBe('yRelative')
   })
-  it('testing yLine', () => {
-    expect(helper2(`yLine(5, %)`)).toBe('xRelative')
+  it('testing yLine', async () => {
+    expect(await helper2(`yLine(5, %)`)).toBe('xRelative')
   })
-  it('testing xLineTo', () => {
-    expect(helper2(`xLineTo(5, %)`)).toBe('yAbsolute')
+  it('testing xLineTo', async () => {
+    expect(await helper2(`xLineTo(5, %)`)).toBe('yAbsolute')
   })
-  it('testing yLineTo', () => {
-    expect(helper2(`yLineTo(5, %)`)).toBe('xAbsolute')
+  it('testing yLineTo', async () => {
+    expect(await helper2(`yLineTo(5, %)`)).toBe('xAbsolute')
   })
 })
 
-function getConstraintTypeFromSourceHelper(
+async function getConstraintTypeFromSourceHelper(
   code: string
-): ReturnType<typeof getConstraintType> {
-  const ast = parse(code)
+): Promise<ReturnType<typeof getConstraintType>> {
+  const ast = await parse(code)
   const args = (ast.body[0] as any).expression.arguments[0].elements as [
     Value,
     Value
@@ -69,10 +69,10 @@ function getConstraintTypeFromSourceHelper(
   const fnName = (ast.body[0] as any).expression.callee.name as ToolTip
   return getConstraintType(args, fnName)
 }
-function getConstraintTypeFromSourceHelper2(
+async function getConstraintTypeFromSourceHelper2(
   code: string
-): ReturnType<typeof getConstraintType> {
-  const ast = parse(code)
+): Promise<ReturnType<typeof getConstraintType>> {
+  const ast = await parse(code)
   const arg = (ast.body[0] as any).expression.arguments[0] as Value
   const fnName = (ast.body[0] as any).expression.callee.name as ToolTip
   return getConstraintType(arg, fnName)
@@ -197,7 +197,7 @@ const part001 = startSketchOn('XY')
   |> yLine(segLen('seg01', %), %) // ln-yLineTo-free should convert to yLine
 `
   it('should transform the ast', async () => {
-    const ast = parse(inputScript)
+    const ast = await parse(inputScript)
     const selectionRanges: Selections['codeBasedSelections'] = inputScript
       .split('\n')
       .filter((ln) => ln.includes('//'))
@@ -284,7 +284,7 @@ const part001 = startSketchOn('XY')
   |> xLineTo(myVar3, %) // select for horizontal constraint 10
   |> angledLineToY([301, myVar], %) // select for vertical constraint 10
 `
-    const ast = parse(inputScript)
+    const ast = await parse(inputScript)
     const selectionRanges: Selections['codeBasedSelections'] = inputScript
       .split('\n')
       .filter((ln) => ln.includes('// select for horizontal constraint'))
@@ -342,7 +342,7 @@ const part001 = startSketchOn('XY')
   |> angledLineToX([333, myVar3], %) // select for horizontal constraint 10
   |> yLineTo(myVar, %) // select for vertical constraint 10
 `
-    const ast = parse(inputScript)
+    const ast = await parse(inputScript)
     const selectionRanges: Selections['codeBasedSelections'] = inputScript
       .split('\n')
       .filter((ln) => ln.includes('// select for vertical constraint'))
@@ -433,7 +433,7 @@ async function helperThing(
   linesOfInterest: string[],
   constraint: ConstraintType
 ): Promise<string> {
-  const ast = parse(inputScript)
+  const ast = await parse(inputScript)
   const selectionRanges: Selections['codeBasedSelections'] = inputScript
     .split('\n')
     .filter((ln) =>
@@ -465,7 +465,7 @@ async function helperThing(
 }
 
 describe('testing getConstraintLevelFromSourceRange', () => {
-  it('should divide up lines into free, partial and fully contrained', () => {
+  it('should divide up lines into free, partial and fully contrained', async () => {
     const code = `const baseLength = 3
 const baseThick = 1
 const armThick = 0.5
@@ -495,7 +495,7 @@ const part001 = startSketchOn('XY')
   |> line([-1.49, 1.06], %) // free
   |> xLine(-3.43 + 0, %) // full
   |> angledLineOfXLength([243 + 0, 1.2 + 0], %) // full`
-    const ast = parse(code)
+    const ast = await parse(code)
     const constraintLevels: ReturnType<
       typeof getConstraintLevelFromSourceRange
     >['level'][] = ['full', 'partial', 'free']

src/lang/std/std.test.ts

@@ -15,9 +15,9 @@ describe('testing angledLineThatIntersects', () => {
   offset: ${offset},
 }, %, "yo2")
 const intersect = segEndX('yo2', part001)`
-    const { root } = await enginelessExecutor(parse(code('-1')))
+    const { root } = await enginelessExecutor(await parse(code('-1')))
     expect(root.intersect.value).toBe(1 + Math.sqrt(2))
-    const { root: noOffset } = await enginelessExecutor(parse(code('0')))
+    const { root: noOffset } = await enginelessExecutor(await parse(code('0')))
     expect(noOffset.intersect.value).toBeCloseTo(1)
   })
 })

src/lang/wasm.ts

@@ -25,6 +25,8 @@ import { AppInfo } from 'wasm-lib/kcl/bindings/AppInfo'
 import { CoreDumpManager } from 'lib/coredump'
 import openWindow from 'lib/openWindow'
 import { DefaultPlanes } from 'wasm-lib/kcl/bindings/DefaultPlanes'
+import { rangeTypeFix } from './workers/types'
+import { parser } from 'lib/singletons'
 
 export type { Program } from '../wasm-lib/kcl/bindings/Program'
 export type { Value } from '../wasm-lib/kcl/bindings/Value'
@@ -103,10 +105,18 @@ const initialise = async () => {
 
 export const initPromise = initialise()
 
-export const rangeTypeFix = (ranges: number[][]): [number, number][] =>
-  ranges.map(([start, end]) => [start, end])
+export type PathToNode = [string | number, string][]
 
-export const parse = (code: string): Program => {
+interface Memory {
+  [key: string]: MemoryItem
+}
+
+export interface ProgramMemory {
+  root: Memory
+  return: ProgramReturn | null
+}
+
+/*export const parse = (code: string): Program => {
   try {
     const program: Program = parse_wasm(code)
     return program
@@ -121,17 +131,10 @@ export const parse = (code: string): Program => {
     console.log(kclError)
     throw kclError
   }
-}
+}*/
 
-export type PathToNode = [string | number, string][]
-
-interface Memory {
-  [key: string]: MemoryItem
-}
-
-export interface ProgramMemory {
-  root: Memory
-  return: ProgramReturn | null
+export const parse = async (code: string): Promise<Program> => {
+  return parser.parse(code)
 }
 
 export const executor = async (

src/lang/workers/parser.ts

@@ -0,0 +1,60 @@
+import init, { parse_wasm } from 'wasm-lib/pkg/wasm_lib'
+import { Program } from 'lang/wasm'
+import { KclError as RustKclError } from 'wasm-lib/kcl/bindings/KclError'
+import { KCLError } from 'lang/errors'
+import {
+  WasmWorkerEventType,
+  WasmWorkerEvent,
+  WasmWorkerOptions,
+  ParserWorkerCall,
+  rangeTypeFix,
+} from 'lang/workers/types'
+
+// Initialise the wasm module.
+const initialise = async (wasmUrl: string) => {
+  const input = await fetch(wasmUrl)
+  const buffer = await input.arrayBuffer()
+  return init(buffer)
+}
+
+onmessage = function (event) {
+  const { worker, eventType, eventData }: WasmWorkerEvent = event.data
+
+  switch (eventType) {
+    case WasmWorkerEventType.Init:
+      let { wasmUrl }: WasmWorkerOptions = eventData as WasmWorkerOptions
+      initialise(wasmUrl)
+        .then((instantiatedModule) => {
+          console.log('Worker: WASM module loaded', worker, instantiatedModule)
+          postMessage({
+            eventType: WasmWorkerEventType.Init,
+            response: { worker: worker, initialized: true },
+          })
+        })
+        .catch((error) => {
+          console.error('Worker: Error loading wasm module', worker, error)
+        })
+      break
+    case WasmWorkerEventType.Call:
+      const data = eventData as ParserWorkerCall
+      try {
+        const program: Program = parse_wasm(data.code)
+        postMessage({ uuid: data.uuid, response: program })
+      } catch (e: any) {
+        const parsed: RustKclError = JSON.parse(e.toString())
+        const kclError = new KCLError(
+          parsed.kind,
+          parsed.msg,
+          rangeTypeFix(parsed.sourceRanges)
+        )
+
+        postMessage({
+          eventType: WasmWorkerEventType.Call,
+          response: { uuid: data.uuid, response: kclError },
+        })
+      }
+      break
+    default:
+      console.error('Worker: Unknown message type', worker, eventType)
+  }
+}

src/lang/workers/types.ts

@@ -0,0 +1,43 @@
+import { KCLError } from 'lang/errors'
+import { Program } from 'lang/wasm'
+
+export enum WasmWorker {
+  Parser = 'parser',
+}
+export enum WasmWorkerEventType {
+  Init = 'init',
+  Call = 'call',
+}
+
+export interface WasmWorkerOptions {
+  wasmUrl: string
+}
+
+export interface ParserWorkerCall {
+  uuid: string
+  code: string
+}
+
+export interface ParserWorkerInitResponse {
+  worker: WasmWorker
+  initialized: boolean
+}
+
+export interface ParserWorkerCallResponse {
+  uuid: string
+  response: Program | KCLError
+}
+
+export interface ParserWorkerResponse {
+  eventType: WasmWorkerEventType
+  response: ParserWorkerInitResponse | ParserWorkerCallResponse
+}
+
+export interface WasmWorkerEvent {
+  eventType: WasmWorkerEventType
+  eventData: Uint8Array | WasmWorkerOptions | ParserWorkerCall
+  worker: WasmWorker
+}
+
+export const rangeTypeFix = (ranges: number[][]): [number, number][] =>
+  ranges.map(([start, end]) => [start, end])

src/lib/selections.ts

@@ -119,9 +119,9 @@ export async function getEventForSelectWithPoint(
   }
 }
 
-export function getEventForSegmentSelection(
+export async function getEventForSegmentSelection(
   obj: Object3D<Object3DEventMap>
-): ModelingMachineEvent | null {
+): Promise<ModelingMachineEvent | null> {
   const group = getParentGroup(obj, [
     STRAIGHT_SEGMENT,
     TANGENTIAL_ARC_TO_SEGMENT,
@@ -143,7 +143,7 @@ export function getEventForSegmentSelection(
   // previous drags don't update ast for efficiency reasons
   // So we want to make sure we have and updated ast with
   // accurate source ranges
-  const updatedAst = parse(codeManager.code)
+  const updatedAst = await parse(codeManager.code)
   const node = getNodeFromPath<CallExpression>(
     updatedAst,
     pathToNode,
@@ -254,10 +254,10 @@ export function processCodeMirrorRanges({
   }
 }
 
-function updateSceneObjectColors(codeBasedSelections: Selection[]) {
+async function updateSceneObjectColors(codeBasedSelections: Selection[]) {
   let updated: Program
   try {
-    updated = parse(recast(kclManager.ast))
+    updated = await parse(recast(kclManager.ast))
   } catch (e) {
     console.error('error parsing code in processCodeMirrorRanges', e)
     return

src/lib/singletons.ts

@@ -2,8 +2,10 @@ import { SceneEntities } from 'clientSideScene/sceneEntities'
 import { SceneInfra } from 'clientSideScene/sceneInfra'
 import { KclManager } from 'lang/KclSingleton'
 import CodeManager from 'lang/codeManager'
+import Parser from 'lang/parser'
 import { EngineCommandManager } from 'lang/std/engineConnection'
 
+export const parser = new Parser()
 export const codeManager = new CodeManager()
 
 export const engineCommandManager = new EngineCommandManager()

src/lib/useCalculateKclExpression.ts

@@ -82,7 +82,7 @@ export function useCalculateKclExpression({
   useEffect(() => {
     const execAstAndSetResult = async () => {
       const code = `const __result__ = ${value}`
-      const ast = parse(code)
+      const ast = await parse(code)
       const _programMem: any = { root: {}, return: null }
       availableVarInfo.variables.forEach(({ key, value }) => {
         _programMem.root[key] = { type: 'userVal', value, __meta: [] }