@strudel/transpiler plugin system

packages/transpiler/plugin-kabelsalat.mjs

@@ -0,0 +1,98 @@
+/*
+plugin-kabelsalat.mjs - <short description TODO>
+Copyright (C) 2022 Strudel contributors - see <https://codeberg.org/uzu/strudel/src/branch/main/packages/superdough/superdough.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 { genExprSource, extractPatternPlaceholders } from './helpers.mjs';
+
+export const transpilerPlugin = {
+  walk: (context) => ({
+    leave: function (node, parent, prop, index) {
+      if (!isKabelCall(node)) return;
+      let [expr, ...rest] = node.arguments;
+      if (!expr) throw new Error('K(...) requires an expression');
+      if (shouldCallKabelExpression(expr)) {
+        expr = {
+          type: 'CallExpression',
+          callee: expr,
+          arguments: [],
+          optional: false,
+        };
+      }
+      const language = 'kabelsalat';
+      const { template, patternExprs } = extractPatternPlaceholders(expr);
+      if (patternExprs.length) {
+        const workletArgs = [
+          /*{ type: 'Literal', value: language },*/
+          { type: 'Literal', value: template },
+          ...patternExprs,
+          ...rest,
+        ];
+        let callee = node.callee;
+        if (callee.type === 'ChainExpression') callee = callee.expression;
+        if (callee.type === 'MemberExpression') {
+          return this.replace({
+            type: 'CallExpression',
+            callee: workletMemberAst(callee.object),
+            arguments: workletArgs,
+            optional: false,
+          });
+        }
+        return this.replace({
+          type: 'CallExpression',
+          callee: { type: 'Identifier', name: 'worklet' },
+          arguments: workletArgs,
+          optional: false,
+        });
+      }
+
+      const kabelSrc = genExprSource(expr);
+      const workletArgs = [/*{ type: 'Literal', value: language },*/ { type: 'Literal', value: kabelSrc }, ...rest];
+
+      let callee = node.callee;
+      if (callee.type === 'ChainExpression') callee = callee.expression;
+      if (callee.type === 'MemberExpression') {
+        return this.replace({
+          type: 'CallExpression',
+          callee: workletMemberAst(callee.object),
+          arguments: workletArgs,
+          optional: false,
+        });
+      }
+      return this.replace({
+        type: 'CallExpression',
+        callee: { type: 'Identifier', name: 'worklet' },
+        arguments: workletArgs,
+        optional: false,
+      });
+    },
+  }),
+};
+
+function isKabelCall(node) {
+  if (node.type !== 'CallExpression') return false;
+  let callee = node.callee;
+  if (callee.type === 'ChainExpression') callee = callee.expression;
+  if (callee.type === 'MemberExpression') return !callee.computed && callee.property?.name === 'K';
+  return callee.type === 'Identifier' && callee.name === 'K';
+}
+
+function shouldCallKabelExpression(expr) {
+  if (expr.type !== 'ArrowFunctionExpression' && expr.type !== 'FunctionExpression') {
+    return false;
+  }
+  if (expr.params.length) {
+    return false;
+  }
+  return expr.body?.type === 'BlockStatement';
+}
+
+function workletMemberAst(objectExpr) {
+  return {
+    type: 'MemberExpression',
+    object: objectExpr,
+    property: { type: 'Identifier', name: 'worklet' },
+    computed: false,
+    optional: false,
+  };
+}