feat:special handle multiple return functions. close 5

README.md

@@ -88,6 +88,7 @@ js2lua(`let a = 1`, { importStatementHoisting: true });
 * [index0To1](#index0To1)
 * [keywords](#keywords)
 * [loop](#loop)
+* [multipleReturnForLuaFunction](#multipleReturnForLuaFunction)
 * [object](#object)
 * [operator](#operator)
 * [optionalNullish](#optionalNullish)
@@ -662,6 +663,39 @@ do
     end
 end
 
+```
+## multipleReturnForLuaFunction
+### js
+```js
+let [ok, res] = pcall(foo)
+let [ok2, res2] = xpcall(foo)
+let [e1, e2] = unpack(bar)
+// comparision
+let [ok3, res3] = pcall2(foo)
+let [ok4, ...res4] = xpcall(foo)
+
+```
+### lua
+```lua
+local ok, res = pcall(foo)
+local ok2, res2 = xpcall(foo)
+local e1, e2 = unpack(bar)
+local ok3, res3
+do
+    local __tmp = pcall2(foo)
+    ok3 = __tmp[1]
+    res3 = __tmp[2]
+end
+local ok4, res4
+do
+    local __tmp = xpcall(foo)
+    ok4 = __tmp[1]
+    res4 = {}
+    for __i = 2, #__tmp do
+        res4[#res4 + 1] = __tmp[__i]
+    end
+end
+
 ```
 ## object
 ### js

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@xiangnanscu/js2lua",
-  "version": "0.42.0",
+  "version": "0.43.0",
   "type": "module",
   "description": "Writing LuaJIT with the expressiveness of JavaScript.",
   "main": "src/js2lua.mjs",

src/App.vue

@@ -50,7 +50,7 @@ const luacode = computed(() => {
   return js2lua(jscode.value, selectOptions.value);
 });
 
-const jsast = computed(() => js2ast(jscode.value, selectOptions.value));
+const jsast = computed(() => js2ast(jscode.value, selectOptions.value)?.program.body);
 function copylua() {
   CopyToClipboard("luacode");
 }

src/js2lua.mjs

@@ -127,6 +127,37 @@ function hasIdentifier(ast, name, depth) {
   );
   return find;
 }
+const multiReturnFunctions = ['pcall', 'xpcall', 'unpack'];
+function isMultiReturnAssignment(ast) {
+  // 检查是否为赋值语句
+  if (ast.type !== 'VariableDeclaration' || ast.declarations.length !== 1) {
+    return false;
+  }
+
+  const declaration = ast.declarations[0];
+
+  // 检查左边是否为数组解构形式
+  if (declaration.id.type !== 'ArrayPattern') {
+    return false;
+  }
+
+  // 检查数组解构的元素是否全部为标识符
+  if (!declaration.id.elements.every(element => element && element.type === 'Identifier')) {
+    return false;
+  }
+
+  // 检查右边是否为函数调用
+  if (declaration.init?.type !== 'CallExpression') {
+    return false;
+  }
+
+  // 检查函数名是否为Lua的多返回值内置函数
+
+  const calleeName = declaration.init.callee.name;
+
+  return multiReturnFunctions.includes(calleeName);
+}
+
 function renameThisToCls(ast) {
   walkAst(ast, (node) => {
     if (node.type == "ThisExpression") {
@@ -441,6 +472,10 @@ function ast2lua(ast, opts = {}) {
       case "File":
         return joinAst(ast.program.body, ";\n");
       case "VariableDeclaration": {
+        if (isMultiReturnAssignment(ast)) {
+          const declare = ast.declarations[0]
+          return `local ${declare.id.elements.map(_ast2lua).join(", ")} = ${_ast2lua(declare.init)}`;
+        }
         const declarePrefix = ast.noPrefix ? "" : "local ";
         return ast.declarations
           .map(_ast2lua)

src/jsInit.js

@@ -1,3 +1,5 @@
+const { a, b: bAlias, ...rest } = { a: 1, b: 2, c: 3, d: 4 }
+const [x, y, ...others] = [1, 2, 3, 4]
 for (i = 0; i < 10; i = i + 2) {
   if (i % 2) {
     continue;

test/multipleReturnForLuaFunction.mjs

@@ -0,0 +1,6 @@
+let [ok, res] = pcall(foo)
+let [ok2, res2] = xpcall(foo)
+let [e1, e2] = unpack(bar)
+// comparision
+let [ok3, res3] = pcall2(foo)
+let [ok4, ...res4] = xpcall(foo)