Reland sticky regexps https://codereview.chromium.org/567313003/

R=svenpanne@chromium.org, yangguo@chromium.org
BUG=

Review URL: https://codereview.chromium.org/580383003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24065 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/bootstrapper.cc

@@ -203,6 +203,7 @@ class Genesis BASE_EMBEDDED {
   // New context initialization.  Used for creating a context from scratch.
   void InitializeGlobal(Handle<GlobalObject> global_object,
                         Handle<JSFunction> empty_function);
+  void InitializeExperimentalGlobal();
   // Installs the contents of the native .js files on the global objects.
   // Used for creating a context from scratch.
   void InstallNativeFunctions();
@@ -1351,6 +1352,20 @@ void Genesis::InstallTypedArray(
 }
 
 
+void Genesis::InitializeExperimentalGlobal() {
+  // TODO(erikcorry): Move this into Genesis::InitializeGlobal once we no
+  // longer need to live behind a flag.
+  Handle<JSObject> builtins(native_context()->builtins());
+
+  Handle<HeapObject> flag(
+      FLAG_harmony_regexps ? heap()->true_value() : heap()->false_value());
+  PropertyAttributes attributes =
+      static_cast<PropertyAttributes>(DONT_DELETE | READ_ONLY);
+  Runtime::DefineObjectProperty(builtins, factory()->harmony_regexps_string(),
+                                flag, attributes).Assert();
+}
+
+
 bool Genesis::CompileBuiltin(Isolate* isolate, int index) {
   Vector<const char> name = Natives::GetScriptName(index);
   Handle<String> source_code =
@@ -2651,6 +2666,7 @@ Genesis::Genesis(Isolate* isolate,
 
   // Install experimental natives.
   if (!InstallExperimentalNatives()) return;
+  InitializeExperimentalGlobal();
 
   // We can't (de-)serialize typed arrays currently, but we are lucky: The state
   // of the random number generator needs no initialization during snapshot

src/flag-definitions.h

@@ -162,6 +162,7 @@ DEFINE_BOOL(harmony_arrow_functions, false, "enable harmony arrow functions")
 DEFINE_BOOL(harmony_classes, false, "enable harmony classes")
 DEFINE_BOOL(harmony_object_literals, false,
             "enable harmony object literal extensions")
+DEFINE_BOOL(harmony_regexps, false, "enable regexp-related harmony features")
 DEFINE_BOOL(harmony, false, "enable all harmony features (except proxies)")
 
 DEFINE_IMPLICATION(harmony, harmony_scoping)
@@ -174,6 +175,7 @@ DEFINE_IMPLICATION(harmony, harmony_arrays)
 DEFINE_IMPLICATION(harmony, harmony_arrow_functions)
 DEFINE_IMPLICATION(harmony, harmony_classes)
 DEFINE_IMPLICATION(harmony, harmony_object_literals)
+DEFINE_IMPLICATION(harmony, harmony_regexps)
 DEFINE_IMPLICATION(harmony_modules, harmony_scoping)
 DEFINE_IMPLICATION(harmony_classes, harmony_scoping)
 DEFINE_IMPLICATION(harmony_classes, harmony_object_literals)

src/heap/heap.h

@@ -287,6 +287,8 @@ namespace internal {
   V(global_string, "global")                                       \
   V(ignore_case_string, "ignoreCase")                              \
   V(multiline_string, "multiline")                                 \
+  V(sticky_string, "sticky")                                       \
+  V(harmony_regexps_string, "harmony_regexps")                     \
   V(input_string, "input")                                         \
   V(index_string, "index")                                         \
   V(last_index_string, "lastIndex")                                \

src/jsregexp.cc

@@ -70,6 +70,9 @@ static JSRegExp::Flags RegExpFlagsFromString(Handle<String> str) {
       case 'm':
         flags |= JSRegExp::MULTILINE;
         break;
+      case 'y':
+        if (FLAG_harmony_regexps) flags |= JSRegExp::STICKY;
+        break;
     }
   }
   return JSRegExp::Flags(flags);
@@ -185,12 +188,14 @@ MaybeHandle<Object> RegExpImpl::Compile(Handle<JSRegExp> re,
 
   if (parse_result.simple &&
       !flags.is_ignore_case() &&
+      !flags.is_sticky() &&
       !HasFewDifferentCharacters(pattern)) {
     // Parse-tree is a single atom that is equal to the pattern.
     AtomCompile(re, pattern, flags, pattern);
     has_been_compiled = true;
   } else if (parse_result.tree->IsAtom() &&
       !flags.is_ignore_case() &&
+      !flags.is_sticky() &&
       parse_result.capture_count == 0) {
     RegExpAtom* atom = parse_result.tree->AsAtom();
     Vector<const uc16> atom_pattern = atom->data();
@@ -430,7 +435,8 @@ bool RegExpImpl::CompileIrregexp(Handle<JSRegExp> re,
   }
   RegExpEngine::CompilationResult result = RegExpEngine::Compile(
       &compile_data, flags.is_ignore_case(), flags.is_global(),
-      flags.is_multiline(), pattern, sample_subject, is_one_byte, &zone);
+      flags.is_multiline(), flags.is_sticky(), pattern, sample_subject,
+      is_one_byte, &zone);
   if (result.error_message != NULL) {
     // Unable to compile regexp.
     Handle<String> error_message = isolate->factory()->NewStringFromUtf8(
@@ -6027,8 +6033,8 @@ void DispatchTableConstructor::VisitAction(ActionNode* that) {
 
 RegExpEngine::CompilationResult RegExpEngine::Compile(
     RegExpCompileData* data, bool ignore_case, bool is_global,
-    bool is_multiline, Handle<String> pattern, Handle<String> sample_subject,
-    bool is_one_byte, Zone* zone) {
+    bool is_multiline, bool is_sticky, Handle<String> pattern,
+    Handle<String> sample_subject, bool is_one_byte, Zone* zone) {
   if ((data->capture_count + 1) * 2 - 1 > RegExpMacroAssembler::kMaxRegister) {
     return IrregexpRegExpTooBig(zone->isolate());
   }
@@ -6055,9 +6061,9 @@ RegExpEngine::CompilationResult RegExpEngine::Compile(
   bool is_end_anchored = data->tree->IsAnchoredAtEnd();
   bool is_start_anchored = data->tree->IsAnchoredAtStart();
   int max_length = data->tree->max_match();
-  if (!is_start_anchored) {
+  if (!is_start_anchored && !is_sticky) {
     // Add a .*? at the beginning, outside the body capture, unless
-    // this expression is anchored at the beginning.
+    // this expression is anchored at the beginning or sticky.
     RegExpNode* loop_node =
         RegExpQuantifier::ToNode(0,
                                  RegExpTree::kInfinity,

src/jsregexp.h

@@ -1661,7 +1661,7 @@ class RegExpEngine: public AllStatic {
   };
 
   static CompilationResult Compile(RegExpCompileData* input, bool ignore_case,
-                                   bool global, bool multiline,
+                                   bool global, bool multiline, bool sticky,
                                    Handle<String> pattern,
                                    Handle<String> sample_subject,
                                    bool is_one_byte, Zone* zone);

src/objects.h

@@ -8034,7 +8034,13 @@ class JSRegExp: public JSObject {
   // IRREGEXP: Compiled with Irregexp.
   // IRREGEXP_NATIVE: Compiled to native code with Irregexp.
   enum Type { NOT_COMPILED, ATOM, IRREGEXP };
-  enum Flag { NONE = 0, GLOBAL = 1, IGNORE_CASE = 2, MULTILINE = 4 };
+  enum Flag {
+    NONE = 0,
+    GLOBAL = 1,
+    IGNORE_CASE = 2,
+    MULTILINE = 4,
+    STICKY = 8
+  };
 
   class Flags {
    public:
@@ -8042,6 +8048,7 @@ class JSRegExp: public JSObject {
     bool is_global() { return (value_ & GLOBAL) != 0; }
     bool is_ignore_case() { return (value_ & IGNORE_CASE) != 0; }
     bool is_multiline() { return (value_ & MULTILINE) != 0; }
+    bool is_sticky() { return (value_ & STICKY) != 0; }
     uint32_t value() { return value_; }
    private:
     uint32_t value_;

src/regexp.js

@@ -22,6 +22,8 @@ function DoConstructRegExp(object, pattern, flags) {
     flags = (pattern.global ? 'g' : '')
         + (pattern.ignoreCase ? 'i' : '')
         + (pattern.multiline ? 'm' : '');
+    if (harmony_regexps)
+        flags += (pattern.sticky ? 'y' : '');
     pattern = pattern.source;
   }
 
@@ -31,6 +33,7 @@ function DoConstructRegExp(object, pattern, flags) {
   var global = false;
   var ignoreCase = false;
   var multiline = false;
+  var sticky = false;
   for (var i = 0; i < flags.length; i++) {
     var c = %_CallFunction(flags, i, StringCharAt);
     switch (c) {
@@ -52,12 +55,18 @@ function DoConstructRegExp(object, pattern, flags) {
         }
         multiline = true;
         break;
+      case 'y':
+        if (!harmony_regexps || sticky) {
+          throw MakeSyntaxError("invalid_regexp_flags", [flags]);
+        }
+        sticky = true;
+        break;
       default:
         throw MakeSyntaxError("invalid_regexp_flags", [flags]);
     }
   }
 
-  %RegExpInitializeObject(object, pattern, global, ignoreCase, multiline);
+  %RegExpInitializeObject(object, pattern, global, ignoreCase, multiline, sticky);
 
   // Call internal function to compile the pattern.
   %RegExpCompile(object, pattern, flags);
@@ -159,8 +168,8 @@ function RegExpExec(string) {
   // algorithm, step 5) even if the value is discarded for non-global RegExps.
   var i = TO_INTEGER(lastIndex);
 
-  var global = this.global;
-  if (global) {
+  var updateLastIndex = this.global || (harmony_regexps && this.sticky);
+  if (updateLastIndex) {
     if (i < 0 || i > string.length) {
       this.lastIndex = 0;
       return null;
@@ -179,7 +188,7 @@ function RegExpExec(string) {
 
   // Successful match.
   lastMatchInfoOverride = null;
-  if (global) {
+  if (updateLastIndex) {
     this.lastIndex = lastMatchInfo[CAPTURE1];
   }
   RETURN_NEW_RESULT_FROM_MATCH_INFO(matchIndices, string);
@@ -207,7 +216,7 @@ function RegExpTest(string) {
   // algorithm, step 5) even if the value is discarded for non-global RegExps.
   var i = TO_INTEGER(lastIndex);
 
-  if (this.global) {
+  if (this.global || (harmony_regexps && this.sticky)) {
     if (i < 0 || i > string.length) {
       this.lastIndex = 0;
       return false;
@@ -222,12 +231,13 @@ function RegExpTest(string) {
     this.lastIndex = lastMatchInfo[CAPTURE1];
     return true;
   } else {
-    // Non-global regexp.
-    // Remove irrelevant preceeding '.*' in a non-global test regexp.
-    // The expression checks whether this.source starts with '.*' and
-    // that the third char is not a '?'.
+    // Non-global, non-sticky regexp.
+    // Remove irrelevant preceeding '.*' in a test regexp.  The expression
+    // checks whether this.source starts with '.*' and that the third char is
+    // not a '?'.  But see https://code.google.com/p/v8/issues/detail?id=3560
     var regexp = this;
-    if (%_StringCharCodeAt(regexp.source, 0) == 46 &&  // '.'
+    if (regexp.source.length >= 3 &&
+        %_StringCharCodeAt(regexp.source, 0) == 46 &&  // '.'
         %_StringCharCodeAt(regexp.source, 1) == 42 &&  // '*'
         %_StringCharCodeAt(regexp.source, 2) != 63) {  // '?'
       regexp = TrimRegExp(regexp);
@@ -264,6 +274,7 @@ function RegExpToString() {
   if (this.global) result += 'g';
   if (this.ignoreCase) result += 'i';
   if (this.multiline) result += 'm';
+  if (harmony_regexps && this.sticky) result += 'y';
   return result;
 }
 

src/runtime.cc

@@ -2548,7 +2548,7 @@ RUNTIME_FUNCTION(Runtime_RegExpConstructResult) {
 
 RUNTIME_FUNCTION(Runtime_RegExpInitializeObject) {
   HandleScope scope(isolate);
-  DCHECK(args.length() == 5);
+  DCHECK(args.length() == 6);
   CONVERT_ARG_HANDLE_CHECKED(JSRegExp, regexp, 0);
   CONVERT_ARG_HANDLE_CHECKED(String, source, 1);
   // If source is the empty string we set it to "(?:)" instead as
@@ -2564,9 +2564,13 @@ RUNTIME_FUNCTION(Runtime_RegExpInitializeObject) {
   CONVERT_ARG_HANDLE_CHECKED(Object, multiline, 4);
   if (!multiline->IsTrue()) multiline = isolate->factory()->false_value();
 
+  CONVERT_ARG_HANDLE_CHECKED(Object, sticky, 5);
+  if (!sticky->IsTrue()) sticky = isolate->factory()->false_value();
+
   Map* map = regexp->map();
   Object* constructor = map->constructor();
-  if (constructor->IsJSFunction() &&
+  if (!FLAG_harmony_regexps &&
+      constructor->IsJSFunction() &&
       JSFunction::cast(constructor)->initial_map() == map) {
     // If we still have the original map, set in-object properties directly.
     regexp->InObjectPropertyAtPut(JSRegExp::kSourceFieldIndex, *source);
@@ -2583,7 +2587,11 @@ RUNTIME_FUNCTION(Runtime_RegExpInitializeObject) {
     return *regexp;
   }
 
-  // Map has changed, so use generic, but slower, method.
+  // Map has changed, so use generic, but slower, method.  We also end here if
+  // the --harmony-regexp flag is set, because the initial map does not have
+  // space for the 'sticky' flag, since it is from the snapshot, but must work
+  // both with and without --harmony-regexp.  When sticky comes out from under
+  // the flag, we will be able to use the fast initial map.
   PropertyAttributes final =
       static_cast<PropertyAttributes>(READ_ONLY | DONT_ENUM | DONT_DELETE);
   PropertyAttributes writable =
@@ -2598,6 +2606,10 @@ RUNTIME_FUNCTION(Runtime_RegExpInitializeObject) {
       regexp, factory->ignore_case_string(), ignoreCase, final).Check();
   JSObject::SetOwnPropertyIgnoreAttributes(
       regexp, factory->multiline_string(), multiline, final).Check();
+  if (FLAG_harmony_regexps) {
+    JSObject::SetOwnPropertyIgnoreAttributes(
+        regexp, factory->sticky_string(), sticky, final).Check();
+  }
   JSObject::SetOwnPropertyIgnoreAttributes(
       regexp, factory->last_index_string(), zero, writable).Check();
   return *regexp;

src/runtime.h

@@ -154,7 +154,7 @@ namespace internal {
   /* Regular expressions */                                \
   F(RegExpCompile, 3, 1)                                   \
   F(RegExpExecMultiple, 4, 1)                              \
-  F(RegExpInitializeObject, 5, 1)                          \
+  F(RegExpInitializeObject, 6, 1)                          \
                                                            \
   /* JSON */                                               \
   F(ParseJson, 1, 1)                                       \

test/cctest/test-regexp.cc

@@ -518,7 +518,7 @@ static RegExpNode* Compile(const char* input, bool multiline, bool is_one_byte,
       NewStringFromUtf8(CStrVector(input)).ToHandleChecked();
   Handle<String> sample_subject =
       isolate->factory()->NewStringFromUtf8(CStrVector("")).ToHandleChecked();
-  RegExpEngine::Compile(&compile_data, false, false, multiline, pattern,
+  RegExpEngine::Compile(&compile_data, false, false, multiline, false, pattern,
                         sample_subject, is_one_byte, zone);
   return compile_data.node;
 }

test/mjsunit/harmony/regexp-sticky.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Flags: --harmony-regexps
+
+var re = /foo.bar/;
+
+assertTrue(!!"foo*bar".match(re));
+assertTrue(!!"..foo*bar".match(re));
+
+var plain = /foobar/;
+
+assertTrue(!!"foobar".match(plain));
+assertTrue(!!"..foobar".match(plain));
+
+var sticky = /foo.bar/y;
+
+assertTrue(!!"foo*bar".match(sticky));
+assertEquals(0, sticky.lastIndex);
+assertFalse(!!"..foo*bar".match(sticky));
+
+var stickyplain = /foobar/y;
+
+assertTrue(!!"foobar".match(stickyplain));
+assertEquals(0, stickyplain.lastIndex);
+assertFalse(!!"..foobar".match(stickyplain));
+
+var global = /foo.bar/g;
+
+assertTrue(global.test("foo*bar"));
+assertFalse(global.test("..foo*bar"));
+global.lastIndex = 0;
+assertTrue(global.test("..foo*bar"));
+
+var plainglobal = /foobar/g;
+
+assertTrue(plainglobal.test("foobar"));
+assertFalse(plainglobal.test("foobar"));
+plainglobal.lastIndex = 0;
+assertTrue(plainglobal.test("foobar"));
+
+var stickyglobal = /foo.bar/gy;
+
+assertTrue(stickyglobal.test("foo*bar"));
+assertEquals(7, stickyglobal.lastIndex);
+assertFalse(stickyglobal.test("..foo*bar"));
+stickyglobal.lastIndex = 0;
+assertFalse(stickyglobal.test("..foo*bar"));
+stickyglobal.lastIndex = 2;
+assertTrue(stickyglobal.test("..foo*bar"));
+assertEquals(9, stickyglobal.lastIndex);
+
+var stickyplainglobal = /foobar/yg;
+assertTrue(stickyplainglobal.sticky);
+stickyplainglobal.sticky = false;
+
+assertTrue(stickyplainglobal.test("foobar"));
+assertEquals(6, stickyplainglobal.lastIndex);
+assertFalse(stickyplainglobal.test("..foobar"));
+stickyplainglobal.lastIndex = 0;
+assertFalse(stickyplainglobal.test("..foobar"));
+stickyplainglobal.lastIndex = 2;
+assertTrue(stickyplainglobal.test("..foobar"));
+assertEquals(8, stickyplainglobal.lastIndex);
+
+assertEquals("/foo.bar/gy", "" + stickyglobal);
+assertEquals("/foo.bar/g", "" + global);
+
+assertTrue(stickyglobal.sticky);
+stickyglobal.sticky = false;
+assertTrue(stickyglobal.sticky);
+
+var stickyglobal2 = new RegExp("foo.bar", "gy");
+assertTrue(stickyglobal2.test("foo*bar"));
+assertEquals(7, stickyglobal2.lastIndex);
+assertFalse(stickyglobal2.test("..foo*bar"));
+stickyglobal2.lastIndex = 0;
+assertFalse(stickyglobal2.test("..foo*bar"));
+stickyglobal2.lastIndex = 2;
+assertTrue(stickyglobal2.test("..foo*bar"));
+assertEquals(9, stickyglobal2.lastIndex);
+
+assertEquals("/foo.bar/gy", "" + stickyglobal2);
+
+assertTrue(stickyglobal2.sticky);
+stickyglobal2.sticky = false;
+assertTrue(stickyglobal2.sticky);
+
+sticky.lastIndex = -1; // Causes sticky regexp to fail fast
+assertFalse(sticky.test("..foo.bar"));
+assertEquals(0, sticky.lastIndex);
+
+sticky.lastIndex = -1; // Causes sticky regexp to fail fast
+assertFalse(!!sticky.exec("..foo.bar"));
+assertEquals(0, sticky.lastIndex);
+
+// ES6 draft says: Even when the y flag is used with a pattern, ^ always
+// matches only at the beginning of Input, or (if Multiline is true) at the
+// beginning of a line.
+var hat = /^foo/y;
+hat.lastIndex = 2;
+assertFalse(hat.test("..foo"));
+
+var mhat = /^foo/my;
+mhat.lastIndex = 2;
+assertFalse(mhat.test("..foo"));
+mhat.lastIndex = 2;
+assertTrue(mhat.test(".\nfoo"));

test/mjsunit/regexp-not-sticky-yet.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Test that sticky regexp support is not affecting V8 when the
+// --harmony-regexps flag is not on.
+
+assertThrows(function() { eval("/foo.bar/y"); }, SyntaxError);
+assertThrows(function() { eval("/foobar/y"); }, SyntaxError);
+assertThrows(function() { eval("/foo.bar/gy"); }, SyntaxError);
+assertThrows(function() { eval("/foobar/gy"); }, SyntaxError);
+assertThrows(function() { new RegExp("foo.bar", "y"); }, SyntaxError);
+assertThrows(function() { new RegExp("foobar", "y"); }, SyntaxError);
+assertThrows(function() { new RegExp("foo.bar", "gy"); }, SyntaxError);
+assertThrows(function() { new RegExp("foobar", "gy"); }, SyntaxError);
+
+var re = /foo.bar/;
+assertEquals("/foo.bar/", "" + re);
+var plain = /foobar/;
+assertEquals("/foobar/", "" + plain);
+
+re.compile("foo.bar");
+assertEquals(void 0, re.sticky);
+
+var global = /foo.bar/g;
+assertEquals("/foo.bar/g", "" + global);
+var plainglobal = /foobar/g;
+assertEquals("/foobar/g", "" + plainglobal);
+
+assertEquals(void 0, re.sticky);
+re.sticky = true; // Has no effect on the regexp, just sets a property.
+assertTrue(re.sticky);
+
+assertTrue(re.test("..foo.bar"));
+
+re.lastIndex = -1; // Ignored for non-global, non-sticky.
+assertTrue(re.test("..foo.bar"));
+assertEquals(-1, re.lastIndex);
+
+re.lastIndex = -1; // Ignored for non-global, non-sticky.
+assertTrue(!!re.exec("..foo.bar"));
+assertEquals(-1, re.lastIndex);