[regexp] Named capture support for string replacements

test/mjsunit/harmony/regexp-named-captures.js

Index: test/mjsunit/harmony/regexp-named-captures.js
diff --git a/test/mjsunit/harmony/regexp-named-captures.js b/test/mjsunit/harmony/regexp-named-captures.js
index 33013c6c9b4b41b88d54b2863ffe1af49bc4ea34..0e256ec67d739c2f31dd3c9da9bf5d0c3b7476f8 100644
--- a/test/mjsunit/harmony/regexp-named-captures.js
+++ b/test/mjsunit/harmony/regexp-named-captures.js
@@ -208,3 +208,59 @@ function toSlowMode(re) {
   });
   assertEquals("bacd", result);
 }
+
+// @@replace with a string replacement argument (no named captures).
+{
+  let re = /(.)(.)/u;
+  assertEquals("$<snd>$<fst>cd", "abcd".replace(re, "$<snd>$<fst>"));
+  assertEquals("bacd", "abcd".replace(re, "$2$1"));
+  assertEquals("$<sndcd", "abcd".replace(re, "$<snd"));
+  assertEquals("$<42a>cd", "abcd".replace(re, "$<42$1>"));
+  assertEquals("$<thd>cd", "abcd".replace(re, "$<thd>"));
+  assertEquals("$<a>cd", "abcd".replace(re, "$<$1>"));
+}
+
+// @@replace with a string replacement argument (global, named captures).
+{
+  let re = /(?<fst>.)(?<snd>.)/gu;
+  assertEquals("badc", "abcd".replace(re, "$<snd>$<fst>"));
+  assertEquals("badc", "abcd".replace(re, "$2$1"));
+  assertThrows(() => "abcd".replace(re, "$<snd"), SyntaxError);
+  assertEquals("", "abcd".replace(re, "$<42$1>"));
+  assertEquals("", "abcd".replace(re, "$<thd>"));
+  assertEquals("", "abcd".replace(re, "$<$1>"));
+}
+
+// @@replace with a string replacement argument (non-global, named captures).
+{
+  let re = /(?<fst>.)(?<snd>.)/u;
+  assertEquals("bacd", "abcd".replace(re, "$<snd>$<fst>"));
+  assertEquals("bacd", "abcd".replace(re, "$2$1"));
+  assertThrows(() => "abcd".replace(re, "$<snd"), SyntaxError);
+  assertEquals("cd", "abcd".replace(re, "$<42$1>"));
+  assertEquals("cd", "abcd".replace(re, "$<thd>"));
+  assertEquals("cd", "abcd".replace(re, "$<$1>"));
+}
+
+// @@replace with a string replacement argument (slow, global, named captures).
+{
+  let re = toSlowMode(/(?<fst>.)(?<snd>.)/gu);
+  assertEquals("badc", "abcd".replace(re, "$<snd>$<fst>"));
+  assertEquals("badc", "abcd".replace(re, "$2$1"));
+  assertThrows(() => "abcd".replace(re, "$<snd"), SyntaxError);
+  assertEquals("", "abcd".replace(re, "$<42$1>"));
+  assertEquals("", "abcd".replace(re, "$<thd>"));
+  assertEquals("", "abcd".replace(re, "$<$1>"));
+}
+
+// @@replace with a string replacement argument (slow, non-global,
+// named captures).
+{
+  let re = toSlowMode(/(?<fst>.)(?<snd>.)/u);
+  assertEquals("bacd", "abcd".replace(re, "$<snd>$<fst>"));
+  assertEquals("bacd", "abcd".replace(re, "$2$1"));
+  assertThrows(() => "abcd".replace(re, "$<snd"), SyntaxError);
+  assertEquals("cd", "abcd".replace(re, "$<42$1>"));
+  assertEquals("cd", "abcd".replace(re, "$<thd>"));
+  assertEquals("cd", "abcd".replace(re, "$<$1>"));
+}