Merge commit '6e92d2345e8231a44556ce7d416451f5f3e6c398' as 'engine262'

2026-08-19 00:31:06 +00:00 · 2026-03-27 10:07:29 +05:30
parent 8f26db5a1f 6e92d2345e
commit b42a69d9f8
433 changed files with 90478 additions and 0 deletions
@@ -0,0 +1,90 @@
+import {
+  ObjectValue, UndefinedValue, JSStringValue, Value,
+} from '../value.mts';
+import { Q } from '../completion.mts';
+import type { ValueEvaluator } from '../evaluator.mts';
+import {
+  Assert,
+  Get,
+  ToString,
+  surroundingAgent,
+} from '#self';
+
+/** https://tc39.es/ecma262/#sec-getsubstitution */
+export function* GetSubstitution(matched: JSStringValue, str: JSStringValue, position: number, captures: readonly (JSStringValue | UndefinedValue)[], namedCaptures: UndefinedValue | ObjectValue, replacementTemplate: JSStringValue): ValueEvaluator<JSStringValue> {
+  const stringLength = str.stringValue().length;
+  Assert(position <= stringLength);
+  const result: string[] = [];
+  let templateRemainder = replacementTemplate.stringValue();
+  let ref: string;
+  let refReplacement: string;
+  while (templateRemainder.length) {
+    if (templateRemainder.startsWith('$$')) {
+      ref = '$$';
+      refReplacement = '$';
+    } else if (templateRemainder.startsWith('$`')) {
+      ref = '$`';
+      refReplacement = str.stringValue().slice(0, position);
+    } else if (templateRemainder.startsWith('$&')) {
+      ref = '$&';
+      refReplacement = matched.stringValue();
+    } else if (templateRemainder.startsWith("$'")) {
+      ref = "$'";
+      const matchLength = matched.stringValue().length;
+      const tailPos = position + matchLength;
+      refReplacement = str.stringValue().slice(Math.min(tailPos, stringLength));
+    } else if (templateRemainder.match(/^\$\d+/)) {
+      let digitCount = templateRemainder.match(/^\$\d\d/) ? 2 : 1;
+      let digits = templateRemainder.slice(1, 1 + digitCount);
+      let index = parseInt(digits, 10);
+      Assert(index >= 0 && index <= 99);
+      const captureLen = captures.length;
+      if (index > captureLen && digitCount === 2) {
+        digitCount = 1;
+        digits = digits[0];
+        index = parseInt(digits, 10);
+      }
+      ref = templateRemainder.slice(0, 1 + digitCount);
+      if (index >= 1 && index <= captureLen) {
+        const capture = captures[index - 1];
+        if (capture instanceof UndefinedValue) {
+          refReplacement = '';
+        } else {
+          refReplacement = capture.stringValue();
+        }
+      } else {
+        refReplacement = ref;
+      }
+    } else if (templateRemainder.startsWith('$<')) {
+      const gtPos = templateRemainder.indexOf('>', 0);
+      if (gtPos === -1 || namedCaptures instanceof UndefinedValue) {
+        ref = '$<';
+        refReplacement = ref;
+      } else {
+        ref = templateRemainder.slice(0, gtPos + 1);
+        const groupName = templateRemainder.slice(2, gtPos);
+        Assert(namedCaptures instanceof ObjectValue);
+        const capture = Q(yield* Get(namedCaptures, Value(groupName)));
+        if (capture instanceof UndefinedValue) {
+          refReplacement = '';
+        } else {
+          refReplacement = (Q(yield* ToString(capture))).stringValue();
+        }
+      }
+    } else {
+      ref = templateRemainder[0];
+      refReplacement = ref;
+    }
+    const refLength = ref.length;
+    templateRemainder = templateRemainder.slice(refLength);
+    result.push(refReplacement);
+  }
+  let result_str;
+  try {
+    result_str = result.join('');
+  } catch (e) {
+    // test262/test/staging/sm/String/replace-math.js
+    return surroundingAgent.Throw('RangeError', 'OutOfRange', 'String too long');
+  }
+  return Value(result_str);
+}