[regexp] Port RegExp.prototype[@@replace]

src/objects.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_OBJECTS_H_
 #define V8_OBJECTS_H_
 
 #include <iosfwd>
 #include <memory>
 
@@ skipping 9466 matching lines @@
                          Handle<Object> search, Handle<Object> position);
   // Perform string match of pattern on subject, starting at start index.
   // Caller must ensure that 0 <= start_index <= sub->length(), as this does not
   // check any arguments.
   static int IndexOf(Isolate* isolate, Handle<String> receiver,
                      Handle<String> search, int start_index);
 
   static Object* LastIndexOf(Isolate* isolate, Handle<Object> receiver,
                              Handle<Object> search, Handle<Object> position);
 
+  // Encapsulates logic related to a match and its capture groups as required
+  // by GetSubstitution.
+  class Match {
+   public:
+    virtual Handle<String> GetMatch() = 0;
+    virtual MaybeHandle<String> GetCapture(int i, bool* capture_exists) = 0;
+    virtual Handle<String> GetPrefix() = 0;
+    virtual Handle<String> GetSuffix() = 0;
+    virtual int CaptureCount() = 0;
+    virtual ~Match() {}
+  };
+
+  // ES#sec-getsubstitution
+  // GetSubstitution(matched, str, position, captures, replacement)
+  // Expand the $-expressions in the string and return a new string with
+  // the result.
+  MUST_USE_RESULT static MaybeHandle<String> GetSubstitution(
+      Isolate* isolate, Match* match, Handle<String> replacement);
+
   // String equality operations.
   inline bool Equals(String* other);
   inline static bool Equals(Handle<String> one, Handle<String> two);
   bool IsUtf8EqualTo(Vector<const char> str, bool allow_prefix_match = false);
   bool IsOneByteEqualTo(Vector<const uint8_t> str);
   bool IsTwoByteEqualTo(Vector<const uc16> str);
 
   // Return a UTF8 representation of the string.  The string is null
   // terminated but may optionally contain nulls.  Length is returned
   // in length_output if length_output is not a null pointer  The string
@@ skipping 1978 matching lines @@
     }
     return value;
   }
 };
 
 
 }  // NOLINT, false-positive due to second-order macros.
 }  // NOLINT, false-positive due to second-order macros.
 
 #endif  // V8_OBJECTS_H_