transpiler package to replace eval package

packages/core/examples/vite-vanilla-repl/main.js

@@ -1,6 +1,6 @@
 import { controls, repl, evalScope } from '@strudel.cycles/core';
 import { getAudioContext, webaudioOutput } from '@strudel.cycles/webaudio';
-import shapeshifter from '@strudel.cycles/eval/shapeshifter.mjs';
+import { transpiler } from '@strudel.cycles/transpiler';
 import tune from './tune.mjs';
 
 const ctx = getAudioContext();
@@ -18,7 +18,7 @@ evalScope(
 const { evaluate } = repl({
   defaultOutput: webaudioOutput,
   getTime: () => ctx.currentTime,
-  transpiler: shapeshifter,
+  transpiler,
 });
 document.getElementById('start').addEventListener('click', () => {
   ctx.resume();

packages/transpiler/index.mjs

@@ -0,0 +1,5 @@
+import { evaluate as _evaluate } from '@strudel.cycles/core';
+import { transpiler } from './transpiler.mjs';
+export * from './transpiler.mjs';
+
+export const evaluate = (code) => _evaluate(code, transpiler);

packages/transpiler/package.json

@@ -0,0 +1,32 @@
+{
+  "name": "@strudel.cycles/transpiler",
+  "version": "0.3.1",
+  "description": "Transpiler for strudel user code. Converts syntactically correct but semantically meaningless JS into evaluatable strudel code.",
+  "main": "index.mjs",
+  "scripts": {
+    "test": "vitest run"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/tidalcycles/strudel.git"
+  },
+  "keywords": [
+    "tidalcycles",
+    "strudel",
+    "pattern",
+    "livecoding",
+    "algorave"
+  ],
+  "author": "Felix Roos <flix91@gmail.com>",
+  "license": "AGPL-3.0-or-later",
+  "bugs": {
+    "url": "https://github.com/tidalcycles/strudel/issues"
+  },
+  "homepage": "https://github.com/tidalcycles/strudel#readme",
+  "dependencies": {
+    "@strudel.cycles/core": "^0.3.1",
+    "acorn": "^8.8.1",
+    "escodegen": "^2.0.0",
+    "estree-walker": "^3.0.1"
+  }
+}

packages/transpiler/test/transpiler.test.mjs

@@ -0,0 +1,39 @@
+/*
+transpiler.test.mjs - <short description TODO>
+Copyright (C) 2022 Strudel contributors - see <https://github.com/tidalcycles/strudel/blob/main/packages/transpiler/test/transpiler.test.mjs>
+This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+import { describe, it, expect } from 'vitest';
+import { transpiler } from '../transpiler.mjs';
+
+describe('transpiler', () => {
+  it('wraps double quote string with mini and adds location', () => {
+    expect(transpiler('"c3"', { wrapAsync: false, addReturn: false })).toEqual("mini('c3').withMiniLocation(0, 4);");
+    expect(transpiler('stack("c3","bd sd")', { wrapAsync: false, addReturn: false })).toEqual(
+      "stack(mini('c3').withMiniLocation(6, 10), mini('bd sd').withMiniLocation(11, 18));",
+    );
+  });
+  it('wraps backtick string with mini and adds location', () => {
+    expect(transpiler('`c3`', { wrapAsync: false, addReturn: false })).toEqual("mini('c3').withMiniLocation(0, 4);");
+  });
+  it('replaces note variables with note strings', () => {
+    expect(transpiler('seq(c3, d3)', { wrapAsync: false, addReturn: false })).toEqual("seq('c3', 'd3');");
+  });
+  it('keeps tagged template literal as is', () => {
+    expect(transpiler('xxx`c3`', { wrapAsync: false, addReturn: false })).toEqual('xxx`c3`;');
+  });
+  it('supports top level await', () => {
+    expect(transpiler("await samples('xxx');", { wrapAsync: false, addReturn: false })).toEqual(
+      "await samples('xxx');",
+    );
+  });
+  /*   it('parses dynamic imports', () => {
+    expect(
+      transpiler("const { default: foo } = await import('https://bar.com/foo.js');", {
+        wrapAsync: false,
+        addReturn: false,
+      }),
+    ).toEqual("const {default: foo} = await import('https://bar.com/foo.js');");
+  }); */
+});

packages/transpiler/transpiler.mjs

@@ -0,0 +1,100 @@
+import escodegen from 'escodegen';
+import { parse } from 'acorn';
+import { walk } from 'estree-walker';
+import { isNote } from '@strudel.cycles/core';
+
+export function transpiler(input, options = {}) {
+  const { wrapAsync = true, addReturn = true } = options;
+
+  let ast = parse(input, {
+    ecmaVersion: 2022,
+    allowAwaitOutsideFunction: true,
+  });
+
+  walk(ast, {
+    enter(node, parent, prop, index) {
+      if (isBackTickString(node, parent)) {
+        const { quasis, start, end } = node;
+        const { raw } = quasis[0].value;
+        this.skip();
+        return this.replace(miniWithLocation(raw, start, end));
+      }
+      if (isStringWithDoubleQuotes(node)) {
+        const { value, start, end } = node;
+        this.skip();
+        return this.replace(miniWithLocation(value, start, end));
+      }
+      if (node.type === 'Identifier' && isNote(node.name)) {
+        this.skip();
+        return this.replace({ type: 'Literal', value: node.name });
+      }
+      // TODO:
+    },
+    leave(node, parent, prop, index) {},
+  });
+
+  const { body } = ast;
+  if (!body?.[body.length - 1]?.expression) {
+    throw new Error('unexpected ast format without body expression');
+  }
+
+  // add return to last statement
+  if (addReturn) {
+    const { expression } = body[body.length - 1];
+    body[body.length - 1] = {
+      type: 'ReturnStatement',
+      argument: expression,
+    };
+  }
+  const output = escodegen.generate(ast);
+  if (wrapAsync) {
+    return `(async ()=>{${output}})()`;
+  }
+  return output;
+}
+
+function isStringWithDoubleQuotes(node, locations, code) {
+  const { raw, type } = node;
+  if (type !== 'Literal') {
+    return false;
+  }
+  return raw[0] === '"';
+}
+
+function isBackTickString(node, parent) {
+  return node.type === 'TemplateLiteral' && parent.type !== 'TaggedTemplateExpression';
+}
+
+function miniWithLocation(value, start, end) {
+  // with location
+  return {
+    type: 'CallExpression',
+    callee: {
+      type: 'MemberExpression',
+      object: {
+        type: 'CallExpression',
+        callee: {
+          type: 'Identifier',
+          name: 'mini',
+        },
+        arguments: [{ type: 'Literal', value }],
+        optional: false,
+      },
+      property: {
+        type: 'Identifier',
+        name: 'withMiniLocation',
+      },
+    },
+    arguments: [
+      {
+        type: 'Literal',
+        value: start,
+      },
+      {
+        type: 'Literal',
+        value: end,
+      },
+    ],
+    optional: false,
+  };
+}