add hw2

node_modules/@jridgewell/sourcemap-codec/src/sourcemap-codec.ts

@@ -0,0 +1,111 @@
+import { comma, decodeInteger, encodeInteger, hasMoreVlq, semicolon } from './vlq';
+import { StringWriter, StringReader } from './strings';
+
+export {
+  decodeOriginalScopes,
+  encodeOriginalScopes,
+  decodeGeneratedRanges,
+  encodeGeneratedRanges,
+} from './scopes';
+export type { OriginalScope, GeneratedRange, CallSite, BindingExpressionRange } from './scopes';
+
+export type SourceMapSegment =
+  | [number]
+  | [number, number, number, number]
+  | [number, number, number, number, number];
+export type SourceMapLine = SourceMapSegment[];
+export type SourceMapMappings = SourceMapLine[];
+
+export function decode(mappings: string): SourceMapMappings {
+  const { length } = mappings;
+  const reader = new StringReader(mappings);
+  const decoded: SourceMapMappings = [];
+  let genColumn = 0;
+  let sourcesIndex = 0;
+  let sourceLine = 0;
+  let sourceColumn = 0;
+  let namesIndex = 0;
+
+  do {
+    const semi = reader.indexOf(';');
+    const line: SourceMapLine = [];
+    let sorted = true;
+    let lastCol = 0;
+    genColumn = 0;
+
+    while (reader.pos < semi) {
+      let seg: SourceMapSegment;
+
+      genColumn = decodeInteger(reader, genColumn);
+      if (genColumn < lastCol) sorted = false;
+      lastCol = genColumn;
+
+      if (hasMoreVlq(reader, semi)) {
+        sourcesIndex = decodeInteger(reader, sourcesIndex);
+        sourceLine = decodeInteger(reader, sourceLine);
+        sourceColumn = decodeInteger(reader, sourceColumn);
+
+        if (hasMoreVlq(reader, semi)) {
+          namesIndex = decodeInteger(reader, namesIndex);
+          seg = [genColumn, sourcesIndex, sourceLine, sourceColumn, namesIndex];
+        } else {
+          seg = [genColumn, sourcesIndex, sourceLine, sourceColumn];
+        }
+      } else {
+        seg = [genColumn];
+      }
+
+      line.push(seg);
+      reader.pos++;
+    }
+
+    if (!sorted) sort(line);
+    decoded.push(line);
+    reader.pos = semi + 1;
+  } while (reader.pos <= length);
+
+  return decoded;
+}
+
+function sort(line: SourceMapSegment[]) {
+  line.sort(sortComparator);
+}
+
+function sortComparator(a: SourceMapSegment, b: SourceMapSegment): number {
+  return a[0] - b[0];
+}
+
+export function encode(decoded: SourceMapMappings): string;
+export function encode(decoded: Readonly<SourceMapMappings>): string;
+export function encode(decoded: Readonly<SourceMapMappings>): string {
+  const writer = new StringWriter();
+  let sourcesIndex = 0;
+  let sourceLine = 0;
+  let sourceColumn = 0;
+  let namesIndex = 0;
+
+  for (let i = 0; i < decoded.length; i++) {
+    const line = decoded[i];
+    if (i > 0) writer.write(semicolon);
+    if (line.length === 0) continue;
+
+    let genColumn = 0;
+
+    for (let j = 0; j < line.length; j++) {
+      const segment = line[j];
+      if (j > 0) writer.write(comma);
+
+      genColumn = encodeInteger(writer, segment[0], genColumn);
+
+      if (segment.length === 1) continue;
+      sourcesIndex = encodeInteger(writer, segment[1], sourcesIndex);
+      sourceLine = encodeInteger(writer, segment[2], sourceLine);
+      sourceColumn = encodeInteger(writer, segment[3], sourceColumn);
+
+      if (segment.length === 4) continue;
+      namesIndex = encodeInteger(writer, segment[4], namesIndex);
+    }
+  }
+
+  return writer.flush();
+}