Issue #1302 - Add self-hosted implementation for string regex .matchAll

This resolves #1302.

4 files changed, 165 insertions, 0 deletions

diff --git a/js/src/builtin/RegExp.cpp b/js/src/builtin/RegExp.cpp
index b7853d533..55e0c8578 100644
--- a/js/src/builtin/RegExp.cpp
+++ b/js/src/builtin/RegExp.cpp
@@ -795,6 +795,7 @@ const JSFunctionSpec js::regexp_methods[] = {
     JS_SELF_HOSTED_FN("exec", "RegExp_prototype_Exec", 1,0),
     JS_SELF_HOSTED_FN("test", "RegExpTest" ,    1,0),
     JS_SELF_HOSTED_SYM_FN(match, "RegExpMatch", 1,0),
+    JS_SELF_HOSTED_SYM_FN(matchAll, "RegExpMatchAll", 1, 0),
     JS_SELF_HOSTED_SYM_FN(replace, "RegExpReplace", 2,0),
     JS_SELF_HOSTED_SYM_FN(search, "RegExpSearch", 1,0),
     JS_SELF_HOSTED_SYM_FN(split, "RegExpSplit", 2,0),
diff --git a/js/src/builtin/RegExp.js b/js/src/builtin/RegExp.js
index 1a2276594..25827743e 100644
--- a/js/src/builtin/RegExp.js
+++ b/js/src/builtin/RegExp.js
@@ -1031,3 +1031,135 @@ function RegExpSpecies() {
     return this;
 }
 _SetCanonicalName(RegExpSpecies, "get [Symbol.species]");
+
+// String.prototype.matchAll proposal.
+//
+// RegExp.prototype [ @@matchAll ] ( string )
+function RegExpMatchAll(string) {
+    // Step 1.
+    var rx = this;
+
+    // Step 2.
+    if (!IsObject(rx))
+        ThrowTypeError(JSMSG_NOT_NONNULL_OBJECT, rx === null ? "null" : typeof rx);
+
+    // Step 3.
+    var str = ToString(string);
+
+    // Step 4.
+    var C = SpeciesConstructor(rx, GetBuiltinConstructor("RegExp"));
+
+    // Step 5.
+    var flags = ToString(rx.flags);
+    
+    // Step 2.b.iii; located here because it needs |flags|.
+    if (!callFunction(std_String_includes, flags, "g")) {
+        ThrowTypeError(JSMSG_BAD_REGEXP_FLAG, "- matchAll requires g");
+    }
+    
+    // Step 6.
+    var matcher = new C(rx, flags);
+
+    // Steps 7-8.
+    matcher.lastIndex = ToLength(rx.lastIndex);
+
+    // Steps 9-12.
+    // Note, always global because non-global throws as per 
+    // https://github.com/tc39/ecma262/pull/1716
+    var flags = REGEXP_GLOBAL_FLAG |
+                (callFunction(std_String_includes, flags, "u") ? REGEXP_UNICODE_FLAG : 0);
+
+    // Step 13.
+    return CreateRegExpStringIterator(matcher, str, flags);
+}
+
+// String.prototype.matchAll proposal.
+//
+// CreateRegExpStringIterator ( R, S, global, fullUnicode )
+function CreateRegExpStringIterator(regexp, string, flags) {
+    // Step 1.
+    assert(typeof string === "string", "|string| is a string value");
+
+    // Steps 2-3.
+    assert(typeof flags === "number", "|flags| is a number value");
+
+    // Steps 4-9.
+    var iterator = NewRegExpStringIterator();
+    UnsafeSetReservedSlot(iterator, REGEXP_STRING_ITERATOR_REGEXP_SLOT, regexp);
+    UnsafeSetReservedSlot(iterator, REGEXP_STRING_ITERATOR_STRING_SLOT, string);
+    UnsafeSetReservedSlot(iterator, REGEXP_STRING_ITERATOR_FLAGS_SLOT, flags | 0);
+    UnsafeSetReservedSlot(iterator, REGEXP_STRING_ITERATOR_DONE_SLOT, false);
+
+    // Step 10.
+    return iterator;
+}
+
+// String.prototype.matchAll proposal.
+//
+// %RegExpStringIteratorPrototype%.next ( )
+function RegExpStringIteratorNext() {
+    // Steps 1-3.
+    var obj;
+    if (!IsObject(this) || (obj = GuardToRegExpStringIterator(this)) === null) {
+        return callFunction(CallRegExpStringIteratorMethodIfWrapped, this,
+                            "RegExpStringIteratorNext");
+    }
+
+    var result = { value: undefined, done: false };
+
+    // Step 4.
+    var done = UnsafeGetReservedSlot(obj, REGEXP_STRING_ITERATOR_DONE_SLOT);
+    if (done) {
+        result.done = true;
+        return result;
+    }
+
+    // Step 5.
+    var regexp = UnsafeGetObjectFromReservedSlot(obj, REGEXP_STRING_ITERATOR_REGEXP_SLOT);
+
+    // Step 6.
+    var string = UnsafeGetStringFromReservedSlot(obj, REGEXP_STRING_ITERATOR_STRING_SLOT);
+
+    // Steps 7-8.
+    var flags = UnsafeGetInt32FromReservedSlot(obj, REGEXP_STRING_ITERATOR_FLAGS_SLOT);
+    var global = !!(flags & REGEXP_GLOBAL_FLAG);
+    var fullUnicode = !!(flags & REGEXP_UNICODE_FLAG);
+
+    // Step 9.
+    var match = RegExpExec(regexp, string, false);
+
+    // Step 10.
+    if (match === null) {
+        // Step 10.a.
+        UnsafeSetReservedSlot(obj, REGEXP_STRING_ITERATOR_DONE_SLOT, true);
+
+        // Step 10.b.
+        result.done = true;
+        return result;
+    }
+
+    // Step 11.a.
+    if (global) {
+        // Step 11.a.i.
+        var matchStr = ToString(match[0]);
+
+        // Step 11.a.ii.
+        if (matchStr.length === 0) {
+            // Step 11.a.ii.1.
+            var thisIndex = ToLength(regexp.lastIndex);
+
+            // Step 11.a.ii.2.
+            var nextIndex = fullUnicode ? AdvanceStringIndex(string, thisIndex) : thisIndex + 1;
+
+            // Step 11.a.ii.3.
+            regexp.lastIndex = nextIndex;
+        }
+    } else {
+        // Step 11.b.i.
+        UnsafeSetReservedSlot(obj, REGEXP_STRING_ITERATOR_DONE_SLOT, true);
+    }
+
+    // Steps 11.a.iii and 11.b.ii.
+    result.value = match;
+    return result;
+}
diff --git a/js/src/builtin/SelfHostingDefines.h b/js/src/builtin/SelfHostingDefines.h
index 6512810ca..117ac7ffd 100644
--- a/js/src/builtin/SelfHostingDefines.h
+++ b/js/src/builtin/SelfHostingDefines.h
@@ -92,6 +92,11 @@
 #define REGEXP_UNICODE_FLAG     0x10
 #define REGEXP_DOTALL_FLAG      0x20
 
+#define REGEXP_STRING_ITERATOR_REGEXP_SLOT 0
+#define REGEXP_STRING_ITERATOR_STRING_SLOT 1
+#define REGEXP_STRING_ITERATOR_FLAGS_SLOT 2
+#define REGEXP_STRING_ITERATOR_DONE_SLOT 3
+
 #define MODULE_OBJECT_ENVIRONMENT_SLOT 2
 
 #define MODULE_STATE_FAILED       0
diff --git a/js/src/builtin/String.js b/js/src/builtin/String.js
index f830b1aa2..d07ec6127 100644
--- a/js/src/builtin/String.js
+++ b/js/src/builtin/String.js
@@ -63,6 +63,33 @@ function String_generic_match(thisValue, regexp) {
     return callFunction(String_match, thisValue, regexp);
 }
 
+// String.prototype.matchAll proposal.
+//
+// String.prototype.matchAll ( regexp )
+function String_matchAll(regexp) {
+    // Step 1.
+    RequireObjectCoercible(this);
+
+    // Step 2.
+    if (regexp !== undefined && regexp !== null) {
+        // Step 2.a.
+        var matcher = GetMethod(regexp, std_matchAll);
+
+        // Step 2.b.
+        if (matcher !== undefined)
+            return callContentFunction(matcher, regexp, this);
+    }
+
+    // Step 3.
+    var string = ToString(this);
+
+    // Step 4.
+    var rx = RegExpCreate(regexp, "g");
+
+    // Step 5.
+    return callContentFunction(GetMethod(rx, std_matchAll), rx, string);
+}
+
 /**
  * A helper function implementing the logic for both String.prototype.padStart
  * and String.prototype.padEnd as described in ES7 Draft March 29, 2016