feat: improve transpiler infrastructure

build.gradle

@@ -31,7 +31,7 @@ task compileEnv(type: NpmTask) {
 }
 task compileTypescript(type: NpmTask) {
 	inputs.files('rollup.config.js');
-	inputs.dir('src/lib/ts');
+	inputs.dir('src/lib/transpiler');
 	outputs.files("build/js/ts.js");
 	// nom nom tasty ram
 	environment.put("NODE_OPTIONS", "--max-old-space-size=4096");

package.json

@@ -1,10 +1,17 @@
 {
 	"scripts": {
 		"build-env": "rollup -c --environment INPUT:src/lib/libs/_entry.ts,OUTPUT:build/js/index.js,POLYFILLS:src/lib/libs/polyfills",
-		"build-ts": "rollup -c --environment INPUT:src/lib/ts/_entry.ts,OUTPUT:build/js/ts.js"
+		"build-ts": "rollup -c --environment INPUT:src/lib/transpiler/_entry.ts,OUTPUT:build/js/ts.js"
 	},
 	"dependencies": {
+		"@babel/core": "^7.26.0",
 		"@babel/runtime": "^7.26.0",
+		"@babel/standalone": "^7.26.4",
+		"@rollup/plugin-json": "^6.1.0",
+		"@types/babel__preset-env": "^7.9.7",
+		"@types/babel__standalone": "^7.1.9",
+		"@types/coffeescript": "^2.5.7",
+		"coffeescript": "^2.7.0",
 		"typescript": "^5.7.2"
 	},
 	"devDependencies": {

rollup.config.js

@@ -4,6 +4,7 @@ const typescript = require("@rollup/plugin-typescript");
 const babel = require("@rollup/plugin-babel");
 const commonjs = require("@rollup/plugin-commonjs");
 const nodeResolve = require("@rollup/plugin-node-resolve");
+const json = require("@rollup/plugin-json");
 const { resolve } = require("path");
 
 const shouldMinify = () => false;
@@ -21,6 +22,7 @@ const construct = (input, output) => defineConfig({
 		},
 		commonjs(),
 		nodeResolve(),
+		json(),
 		babel({
 			extensions: [],
 			exclude: ["node_modules/**"],
@@ -107,6 +109,14 @@ const construct = (input, output) => defineConfig({
 			path: "null",
 			os: "null",
 			inspector: "null",
+			tty: "null",
+			util: "null",
+			assert: "null",
+			url: "null",
+			"@babel/preset-typescript/package.json": "null",
+			module: "null",
+			process: "null",
+			v8: "null",
 		},
 		// plugins: [babel.getBabelOutputPlugin({
 		// 	allowAllFormats: true,

src/lib/transpiler/_entry.ts

@@ -0,0 +1,4 @@
+import coffeescript from "./coffeescript.ts";
+import babel from "./babel.ts";
+
+register(v => coffeescript(babel(v)));

src/lib/transpiler/babel.ts

@@ -0,0 +1,25 @@
+import { SourceMap } from "./map.ts";
+import { transform } from "@babel/standalone";
+// import presetEnv from "@babel/preset-env";
+
+export default function babel(next: Compiler): Compiler {
+	print("Loaded babel!");
+	
+	return (filename, code, prevMap) => {
+		const res = transform(code, {
+			filename,
+			sourceMaps: true,
+		});
+
+		const map = SourceMap.parse({
+			file: "babel-internal://" + filename,
+			mappings: res.map!.mappings,
+			sources: [filename],
+		});
+
+		const compiled = next("babel-internal://" + filename, res.code!, SourceMap.chain(map, prevMap));
+		registerSource(filename, code);
+		return compiled;
+	};
+}
+

src/lib/transpiler/coffeescript.ts

@@ -0,0 +1,28 @@
+import { compile } from "coffeescript";
+import { SourceMap } from "./map.ts";
+
+export default function coffee(next: Compiler): Compiler {
+	print("Loaded coffeescript!");
+	
+	return (filename, code, prevMap) => {
+		const {
+			js: result,
+			v3SourceMap: rawMap,
+		} = compile(code, {
+			filename,
+			sourceMap: true,
+			bare: true,
+		});
+
+		const map = SourceMap.parse({
+			file: "coffee-internal://" + filename,
+			mappings: JSON.parse(rawMap).mappings,
+			sources: [filename],
+		});
+
+		const compiled = next("coffee-internal://" + filename, result, SourceMap.chain(map, prevMap));
+		registerSource(filename, code);
+		return compiled;
+	};
+}
+

src/lib/transpiler/map.ts

@@ -123,13 +123,16 @@ export class VLQSourceMap {
 
 	public static parseVLQ(compiled: string, filenames: string[], raw: string): VLQSourceMap {
 		const mapping = decodeVLQ(raw);
-		const res = new Map<string, [start: number, dst: Location][][]>();
+		const file: [start: number, dst: Location][][] = [];
+		const res = new Map<string, [start: number, dst: Location][][]>([[compiled, file]]);
 
 		let originalRow = 0;
 		let originalCol = 0;
 		let originalFile = 0;
+		const lastCols = new Set<number>();
 
 		for (let compiledRow = 0; compiledRow < mapping.length; compiledRow++) {
+			const line = file[compiledRow] ??= [];
 			let compiledCol = 0;
 
 			for (const rawSeg of mapping[compiledRow]) {
@@ -138,12 +141,13 @@ export class VLQSourceMap {
 				originalRow += rawSeg.length > 2 ? rawSeg[2] : 0;
 				originalCol += rawSeg.length > 3 ? rawSeg[3] : 0;
 
-				let file = res.get(compiled);
+				if (!lastCols.has(compiledCol)) {
-				if (file == null) res.set(compiled, file = []);
-
-				const line = file[compiledRow] ??= [];
 					line[line.length] = [compiledCol, [filenames[originalFile], originalRow, originalCol]];
 				}
+				lastCols.add(compiledCol);
+			}
+
+			line.sort((a, b) => a[0] - b[0]);
 		}
 
 		return new VLQSourceMap(res);

src/lib/transpiler/types.ts

@@ -0,0 +1,10 @@
+import { type SourceMap } from "./map.ts";
+
+declare global {
+	type CompilerFactory = (next: Compiler) => Compiler;
+	type Compiler = (filename: string, src: string, mapper: SourceMap) => Function;
+
+	function print(...args: any[]): void;
+	function register(factory: CompilerFactory): void;
+	function registerSource(filename: string, src: string): void;
+}

src/lib/transpiler/typescript.ts

@@ -17,7 +17,7 @@ function resource(name: string) {
 	else return resources[name] = getResource(name);
 }
 
-register(next => {
+export default function typescript(next: Compiler): Compiler {
 	const files: Record<string, IScriptSnapshot> = {};
 	const versions: Record<string, number> = {};
 	let declI = 0;
@@ -34,6 +34,7 @@ register(next => {
 		forceConsistentCasingInFileNames: true,
 		declaration: true,
 		sourceMap: true,
+		downlevelIteration: true,
 	};
 
 	let service: LanguageService;
@@ -114,7 +115,7 @@ register(next => {
 		const result = outputs["/src.js"];
 		const declaration = outputs["/src.d.ts"];
 
-		const compiled = next("ts-internal://" + filename, result, SourceMap.chain(prevMap, map));
+		const compiled = next("ts-internal://" + filename, result, SourceMap.chain(map, prevMap));
 		registerSource(filename, code);
 
 		return function (this: any) {
@@ -123,4 +124,4 @@ register(next => {
 			return res;
 		};
 	};
-});
+}