tmp

src/scopes.ts

@@ -0,0 +1,117 @@
+import {
+  comma,
+  decodeInteger,
+  encodeInteger,
+  hasMoreVlq,
+  indexOf,
+  maybeWrite,
+  posOut,
+  semicolon,
+  td,
+} from './vlq';
+
+type Line = number;
+type Column = number;
+type Kind = number;
+type Name = number;
+type Var = number;
+
+type OriginalScope =
+  | [Line, Column, Line, Column, Kind, Name]
+  | [Line, Column, Line, Column, Kind, Name, Var]
+  | [Line, Column, Line, Column, Kind, Name, Var, Var]
+  | [Line, Column, Line, Column, Kind, Name, Var, Var, Var]
+  | [Line, Column, Line, Column, Kind, Name, Var, Var, Var, Var]
+  | [Line, Column, Line, Column, Kind, Name, Var, Var, Var, Var, Var];
+
+const NO_NAME = -1;
+
+export function decodeOriginalScopes(input: string): OriginalScope[] {
+  let line = 0;
+  let column = 0;
+  let namesIndex = 0;
+  let varsIndex = 0;
+  const scopes: OriginalScope[] = [];
+  const stack: OriginalScope[] = [];
+
+  for (let i = 0; i < input.length; i = posOut + 1) {
+    line = decodeInteger(input, i, line);
+    column = decodeInteger(input, posOut, column);
+
+    if (!hasMoreVlq(input, posOut, length)) {
+      const last = stack.pop()!;
+      last[2] = line;
+      last[3] = column;
+      continue;
+    }
+
+    const kind = decodeInteger(input, posOut, 0);
+    const fields = decodeInteger(input, posOut, 0);
+    const name = fields & 0b1 ? decodeInteger(input, posOut, namesIndex) : NO_NAME;
+    const scope: OriginalScope = [line, column, 0, 0, kind, name];
+    stack.push(scope);
+
+    const index = indexOf(input, ',', posOut);
+    while (posOut < index) {
+      varsIndex = decodeInteger(input, posOut, varsIndex);
+      scope.push(varsIndex);
+    }
+  }
+
+  return scopes;
+}
+
+export function encodeOriginalScopes(scopes: OriginalScope[]): string {
+  let out = '';
+  if (scopes.length === 0) return out;
+
+  const bufLength = 1024 * 16;
+  const subLength = bufLength - (7 * 6 + 1);
+  const buf = new Uint8Array(bufLength);
+  const sub = buf.subarray(0, subLength);
+  let pos = 0;
+
+  const endStack: number[] = [0, 0];
+  let { 2: lastEndLine, 3: lastEndColumn } = scopes[scopes.length - 1];
+  let line = 0;
+  let column = 0;
+  let namesIndex = 0;
+  let varsIndex = 0;
+
+  for (let i = 0; i < scopes.length; i++, pos = posOut) {
+    const scope = scopes[i];
+    const { 0: startLine, 1: startColumn, 2: endLine, 3: endColumn, 4: name } = scope;
+
+    out = maybeWrite(out, buf, pos, buf, bufLength);
+    pos = posOut;
+    if (i > 0) buf[pos++] = semicolon;
+
+    while (startLine > lastEndLine || (startLine === lastEndLine && startColumn >= lastEndColumn)) {
+      out = maybeWrite(out, sub, pos, buf, subLength);
+
+      line = encodeInteger(buf, posOut, lastEndLine, line);
+      column = encodeInteger(buf, posOut, lastEndColumn, column);
+      pos = posOut;
+      buf[pos++] = comma;
+
+      lastEndColumn = endStack.pop()!;
+      lastEndLine = endStack.pop()!;
+    }
+
+    line = encodeInteger(buf, pos, startLine, line);
+    column = encodeInteger(buf, posOut, startColumn, column);
+    endStack.push(endLine);
+    endStack.push(endColumn);
+    lastEndLine = endLine;
+    lastEndColumn = endColumn;
+
+    encodeInteger(buf, posOut, name === NO_NAME ? 0 : 1, 0);
+    if (name !== NO_NAME) namesIndex = encodeInteger(buf, posOut, name, namesIndex);
+
+    for (let j = 5; j < scope.length; j++) {
+      out = maybeWrite(out, sub, pos, buf, subLength);
+      varsIndex = encodeInteger(buf, posOut, scope[j], varsIndex);
+    }
+  }
+  while (endStack.length > 0) {}
+}