refactor: implement source mapping in javascript, instead of java

src/lib/ts/_entry.ts

@@ -1,15 +1,13 @@
 import { createDocumentRegistry, createLanguageService, ModuleKind, ScriptSnapshot, ScriptTarget, type Diagnostic, type CompilerOptions, type IScriptSnapshot, flattenDiagnosticMessageText, CompilerHost, LanguageService } from "typescript";
+import { SourceMap } from "./map.ts";
 
 declare function getResource(name: string): string | undefined;
 declare function print(...args: any[]): void;
 declare function register(factory: CompilerFactory): void;
-declare function parseVLQ(compiled: string, original: string, map: string): (loc: Location) => Location;
-declare function chainMaps(...mappers: ((loc: Location) => Location)[]): (loc: Location) => Location;
 declare function registerSource(filename: string, src: string): void;
 
-type Location = readonly [filename: string, line: number, col: number];
 type CompilerFactory = (next: Compiler) => Compiler;
-type Compiler = (filename: string, src: string, mapper: (loc: Location) => Location) => Function;
+type Compiler = (filename: string, src: string, mapper: SourceMap) => Function;
 
 const resources: Record<string, string | undefined> = {};
 
@@ -108,11 +106,15 @@ register(next => {
 		}
 
 		const rawMap = JSON.parse(outputs["/src.js.map"]);
-		const map = parseVLQ(filename, filename, rawMap.mappings);
+		const map = SourceMap.parse({
+			file: "ts-internal://" + filename,
+			mappings: rawMap.mappings,
+			sources: [filename],
+		});
 		const result = outputs["/src.js"];
 		const declaration = outputs["/src.d.ts"];
 
-		const compiled = next(filename, result, chainMaps(prevMap, map));
+		const compiled = next("ts-internal://" + filename, result, SourceMap.chain(prevMap, map));
 		registerSource(filename, code);
 
 		return function (this: any) {

src/lib/ts/map.ts

@@ -0,0 +1,178 @@
+const map: number[] = [];
+let j = 0;
+
+for (let i = 65; i <= 90; i++) map[i] = j++;
+for (let i = 97; i <= 122; i++) map[i] = j++;
+map[43] = j++;
+map[47] = j++;
+
+export type Location = readonly [file: string, line: number, start: number];
+
+export function decodeVLQ(val: string): number[][][] {
+	const lines: number[][][] = [];
+
+	for (const line of val.split(";", -1)) {
+		const elements: number[][] = [];
+
+		for (const el of line.split(",", -1)) {
+			if (el.length === 0) elements.push([]);
+			else {
+				const list: number[] = [];
+
+				for (let i = 0; i < el.length;) {
+					let sign = 1;
+					let curr = map[el.charCodeAt(i++)];
+					let cont = (curr & 0x20) === 0x20;
+					if ((curr & 1) === 1) sign = -1;
+					let res = (curr & 0b11110) >> 1;
+					let n = 4;
+		
+					for (; i < el.length && cont;) {
+						curr = map[el.charCodeAt(i++)];
+						cont = (curr & 0x20) == 0x20;
+						res |= (curr & 0b11111) << n;
+						n += 5;
+						if (!cont) break;
+					}
+
+					list.push(res * sign);
+				}
+
+				elements.push(list);
+			}
+		}
+
+		lines.push(elements);
+	}
+
+	return lines;
+}
+
+export namespace Location {
+	export function compare(a: Location, b: Location) {
+		const { 0: filenameA, 1: lineA, 2: startA } = a;
+		const { 0: filenameB, 1: lineB, 2: startB } = b;
+
+		if (filenameA < filenameB) return -1;
+		if (filenameA > filenameB) return 1;
+
+		const lineI = lineA - lineB;
+		if (lineI !== 0) return lineI;
+
+		return startA - startB;
+	}
+	export function comparePoints(a: Location, b: Location) {
+		const { 1: lineA, 2: startA } = a;
+		const { 1: lineB, 2: startB } = b;
+
+		const lineI = lineA - lineB;
+		if (lineI !== 0) return lineI;
+
+		return startA - startB;
+	}
+}
+
+export interface SourceMap {
+	(loc: Location): Location | undefined;
+}
+
+export class VLQSourceMap {
+	public constructor(
+		public readonly array: Map<string, [start: number, dst: Location][][]>,
+	) { }
+
+	public converter() {
+		return (src: Location) => {
+			const file = this.array.get(src[0]);
+			if (file == null) return src;
+
+			const line = file[src[1]];
+			if (line == null || line.length === 0) return undefined;
+
+			let a = 0;
+			let b = line.length;
+
+			while (true) {
+				const done = b - a <= 1;
+	
+				const mid = (a + b) >> 1;
+				const el = line[mid];
+
+				const cmp = el[0] - src[1];
+
+				if (cmp < 0) {
+					if (done) {
+						if (b >= line.length) return undefined;
+						break;
+					}
+					a = mid;
+				}
+				else if (cmp > 0) {
+					if (done) {
+						if (a <= 0) return undefined;
+						break;
+					}
+					b = mid;
+				}
+				else return el[1];
+			}
+
+			return line[b][1];
+		};
+	}
+
+	public static parseVLQ(compiled: string, filenames: string[], raw: string): VLQSourceMap {
+		const mapping = decodeVLQ(raw);
+		const res = new Map<string, [start: number, dst: Location][][]>();
+
+		let originalRow = 0;
+		let originalCol = 0;
+		let originalFile = 0;
+
+		for (let compiledRow = 0; compiledRow < mapping.length; compiledRow++) {
+			let compiledCol = 0;
+
+			for (const rawSeg of mapping[compiledRow]) {
+				compiledCol += rawSeg.length > 0 ? rawSeg[0] : 0;
+				originalFile += rawSeg.length > 1 ? rawSeg[1] : 0;
+				originalRow += rawSeg.length > 2 ? rawSeg[2] : 0;
+				originalCol += rawSeg.length > 3 ? rawSeg[3] : 0;
+
+				let file = res.get(compiled);
+				if (file == null) res.set(compiled, file = []);
+
+				const line = file[compiledRow] ??= [];
+				line[line.length] = [compiledCol, [filenames[originalFile], originalRow, originalCol]];
+			}
+		}
+
+		return new VLQSourceMap(res);
+	}
+	public static parse(raw: string | { file: string, mappings: string, sources: string[] }) {
+		if (typeof raw === "string") raw = JSON.parse(raw) as { file: string, mappings: string, sources: string[] };
+
+		const compiled = raw.file;
+		const mapping = raw.mappings;
+		let filenames = raw.sources;
+		if (filenames.length === 0 || filenames.length === 1 && filenames[0] === "") filenames = [compiled];
+
+		return this.parseVLQ(compiled, filenames, mapping);
+	}
+}
+
+export namespace SourceMap {
+	export function parse(raw: string | { file: string, mappings: string, sources: string[] }) {
+		return VLQSourceMap.parse(raw).converter();
+	}
+	export function chain(...maps: SourceMap[]): SourceMap {
+		return loc => {
+			for (const el of maps) {
+				const tmp = el(loc);
+				if (tmp == null) return undefined;
+				else loc = tmp;
+			}
+
+			return loc;
+		};
+	}
+}

src/main/java/me/topchetoeu/jscript/common/mapping/FunctionMap.java

@@ -56,10 +56,14 @@ public class FunctionMap {
 			var newBreakpoints = new HashMap<Location, BreakpointType>();
 
 			for (var key : sourceMap.keySet()) {
-				newSourceMaps.put(key, mapper.apply(sourceMap.get(key)));
+				var mapped = mapper.apply(sourceMap.get(key));
+				if (mapped == null) continue;
+				newSourceMaps.put(key, mapped);
 			}
 			for (var key : breakpoints.keySet()) {
-				newBreakpoints.put(mapper.apply(key), breakpoints.get(key));
+				var mapped = mapper.apply(key);
+				if (mapped == null) continue;
+				newBreakpoints.put(mapped, breakpoints.get(key));
 			}
 
 			sourceMap.clear();

src/main/java/me/topchetoeu/jscript/repl/mapping/NativeMapper.java

@@ -25,6 +25,7 @@ public class NativeMapper extends FunctionValue {
 		);
 
 		var res = mapper.apply(loc);
+		if (res == null) return Value.UNDEFINED;
 
 		return new ArrayValue(
 			StringValue.of(res.filename().toString()),
@@ -52,12 +53,14 @@ public class NativeMapper extends FunctionValue {
 				NumberValue.of(loc.start())
 			);
 
-			var rawRes = (ArrayLikeValue)func.apply(env, Value.UNDEFINED, rawLoc);
+			var rawRes = func.apply(env, Value.UNDEFINED, rawLoc);
-			return Location.of(
+			if (rawRes instanceof ArrayLikeValue arr) return Location.of(
-				Filename.parse(rawRes.get(0).toString(env)),
+				Filename.parse(arr.get(0).toString(env)),
-				rawRes.get(1).toNumber(env).getInt(),
+				arr.get(1).toNumber(env).getInt(),
-				rawRes.get(2).toNumber(env).getInt()
+				arr.get(2).toNumber(env).getInt()
 			);
+			else if (rawRes == Value.UNDEFINED || rawRes == Value.NULL) return null;
+			else throw EngineException.ofType("Location must be an array, null or undefined");
 		};
 	}
 }

src/main/java/me/topchetoeu/jscript/repl/mapping/SourceMap.java

@@ -1,123 +0,0 @@
-package me.topchetoeu.jscript.repl.mapping;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.TreeMap;
-import java.util.stream.Collectors;
-
-import me.topchetoeu.jscript.common.json.JSON;
-import me.topchetoeu.jscript.common.parsing.Filename;
-import me.topchetoeu.jscript.common.parsing.Location;
-
-public class SourceMap {
-	private final TreeMap<Long, Long> origToComp = new TreeMap<>();
-	private final TreeMap<Long, Long> compToOrig = new TreeMap<>();
-	private final Filename compiled, original;
-
-	public Location toCompiled(Location loc) { return convert(original, compiled, loc, origToComp); }
-	public Location toOriginal(Location loc) { return convert(compiled, original, loc, compToOrig); }
-
-	private void add(long orig, long comp) {
-		var a = origToComp.remove(orig);
-		var b = compToOrig.remove(comp);
-
-		if (b != null) origToComp.remove(b);
-		if (a != null) compToOrig.remove(a);
-
-		origToComp.put(orig, comp);
-		compToOrig.put(comp, orig);
-	}
-
-	public SourceMap apply(SourceMap map) {
-		var res = new SourceMap(map.compiled, map.original);
-
-		for (var el : new ArrayList<>(origToComp.entrySet())) {
-			var mapped = convert(el.getValue(), map.origToComp);
-			res.origToComp.put(el.getKey(), mapped);
-		}
-		for (var el : new ArrayList<>(compToOrig.entrySet())) {
-			var mapped = convert(el.getKey(), map.compToOrig);
-			res.compToOrig.put(mapped, el.getValue());
-			res.add(el.getValue(), mapped);
-		}
-
-		return res;
-	}
-
-	public SourceMap clone() {
-		var res = new SourceMap(this.compiled, this.original);
-		res.origToComp.putAll(this.origToComp);
-		res.compToOrig.putAll(this.compToOrig);
-		return res;
-	}
-
-	public SourceMap(Filename compiled, Filename original) {
-		this.compiled = compiled;
-		this.original = original;
-	}
-
-	public static SourceMap parse(Filename compiled, Filename original, String raw) {
-		var mapping = VLQ.decodeMapping(raw);
-		var res = new SourceMap(compiled, original);
-
-		var compRow = 0l;
-		var compCol = 0l;
-
-		for (var origRow = 0; origRow < mapping.length; origRow++) {
-			var origCol = 0;
-
-			for (var rawSeg : mapping[origRow]) {
-				if (rawSeg.length > 1 && rawSeg[1] != 0) throw new IllegalArgumentException("Source mapping is to more than one files.");
-				origCol += rawSeg.length > 0 ? rawSeg[0] : 0;
-				compRow += rawSeg.length > 2 ? rawSeg[2] : 0;
-				compCol += rawSeg.length > 3 ? rawSeg[3] : 0;
-
-				var compPacked = ((long)compRow << 32) | compCol;
-				var origPacked = ((long)origRow << 32) | origCol;
-
-				res.add(origPacked, compPacked);
-			}
-		}
-
-		return res;
-	}
-	public static List<String> getSources(String raw) {
-		var json = JSON.parse(null, raw).map();
-		return json
-			.list("sourcesContent")
-			.stream()
-			.map(v -> v.string())
-			.collect(Collectors.toList());
-	}
-
-	public static SourceMap chain(SourceMap ...maps) {
-		if (maps.length == 0) return null;
-		var res = maps[0];
-
-		for (var i = 1; i < maps.length; i++) res = res.apply(maps[i]);
-
-		return res;
-	}
-
-	private static Long convert(long packed, TreeMap<Long, Long> map) {
-		if (map.containsKey(packed)) return map.get(packed);
-		var key = map.floorKey(packed);
-		if (key == null) return null;
-		else return map.get(key);
-	}
-
-	private static Location convert(Filename src, Filename dst, Location loc, TreeMap<Long, Long> map) {
-		if (!loc.filename().equals(src)) return loc;
-
-		var packed = ((loc.line()) << 32) | (loc.start());
-		var resPacked = convert(packed, map);
-
-		if (resPacked == null) return null;
-		else return Location.of(dst, (int)(resPacked >> 32), (int)(resPacked & 0xFFFF));
-	}
-
-	// public static SourceMap of(String filename, String raw) {
-	// 	var json = JSON.parse(Filename.parse(filename), raw);
-	// 	return new SourceMap();
-	// }
-}

src/main/java/me/topchetoeu/jscript/repl/mapping/VLQ.java

@@ -1,95 +0,0 @@
-package me.topchetoeu.jscript.repl.mapping;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class VLQ {
-    private static final String ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
-
-    private static long[] toArray(List<Long> list) {
-        var arr = new long[list.size()];
-        for (var i = 0; i < list.size(); i++) arr[i] = list.get(i);
-        return arr;
-    }
-
-    public static String encode(long... arr) {
-        var raw = new StringBuilder();
-
-        for (var data : arr) {
-            var b = data < 0 ? 1 : 0;
-            data = Math.abs(data);
-            b |= (int)(data & 0b1111) << 1;
-            data >>= 4;
-            b |=  data > 0 ? 0x20 : 0;;
-            raw.append(ALPHABET.charAt(b));
-
-            while (data > 0) {
-                b = (int)(data & 0b11111);
-                data >>= 5;
-                b |= data > 0 ? 0x20 : 0;
-                raw.append(ALPHABET.charAt(b));
-            }
-        }
-
-        return raw.toString();
-    }
-    public static long[] decode(String val) {
-        if (val.length() == 0) return new long[0];
-
-        var list = new ArrayList<Long>();
-
-        for (var i = 0; i < val.length();) {
-            var sign = 1;
-            var curr = ALPHABET.indexOf(val.charAt(i++));
-            var cont = (curr & 0x20) == 0x20;
-            if ((curr & 1) == 1) sign = -1;
-            long res = (curr & 0b11110) >> 1;
-            var n = 4;
-
-            for (; i < val.length() && cont;) {
-                curr = ALPHABET.indexOf(val.charAt(i++));
-                cont = (curr & 0x20) == 0x20;
-                res |= (curr & 0b11111) << n;
-                n += 5;
-                if (!cont) break;
-            }
-
-            list.add(res * sign);
-        }
-
-        return toArray(list);
-    }
-
-    public static String encodeMapping(long[][][] arr) {
-        var res = new StringBuilder();
-        var semicolon = false;
-        
-        for (var line : arr) {
-            var comma = false;
-
-            if (semicolon) res.append(";");
-            semicolon = true;
-
-            for (var el : line) {
-                if (comma) res.append(",");
-                comma = true;
-                res.append(encode(el));
-            }
-        }
-
-        return res.toString();
-    }
-    public static long[][][] decodeMapping(String val) {
-        var lines = new ArrayList<long[][]>();
-
-        for (var line : val.split(";", -1)) {
-            var elements = new ArrayList<long[]>();
-            for (var el : line.split(",", -1)) {
-                elements.add(decode(el));
-            }
-            lines.add(elements.toArray(new long[0][]));
-        }
-
-        return lines.toArray(new long[0][][]);
-    }
-}