Implement Function.prototype.toMethod.

test/mjsunit/harmony/toMethod.js

+// Copyright 2013 the V8 project authors. All rights reserved.

[arv (Not doing code reviews), 2014/08/20 15:35:53]

Use short copyright header with the year 2014

+// 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-classes --allow-natives-syntax
+
+
+(function ToMethodSingleClass() {
+  function f(x) {
+    var a = [0, 1, 2]
+    return a[x];
+  }
+
+  function ClassD() { }
+
+  assertEquals(1, f(1));
+  var g = f.toMethod(ClassD.prototype);
+  assertEquals(1, g(1));
+  assertEquals(undefined, f[%HomeObjectSymbol()]);
+  assertEquals(ClassD.prototype, g[%HomeObjectSymbol()]);
+}());
+
+
+(function ToMethodClassHierarchy() {
+  function f(x) {
+    return function g(y)  { x++; return x + y; };
+  }
+
+  function Base() {}
+  function Derived() { }
+  Derived.prototype = Object.create(Base.prototype);
+
+  var q = f(0);
+  assertEquals(2, q(1));
+  assertEquals(3, q(1));
+  var g = q.toMethod(Derived.prototype);
+  assertFalse(g === q);
+  assertEquals(4, g(1));
+  assertEquals(5, q(1));
+}());
+
+
+(function ToMethodErrorCases() {
+  var sFun = Function.prototype.toMethod;
+  assertThrows(function() { sFun.call({}); }, TypeError);
+  assertThrows(function() { sFun.call({}, {}); }, TypeError);
+  function f(){};
+  assertThrows(function() { f.toMethod(1); }, TypeError);
+}());
+
+
+(function ToMethodPrototypeChain() {
+  var o = {};
+  var o1 = {};
+  function f() { }
+
+  function g() { }
+
+  var fMeth = f.toMethod(o);
+  assertEquals(o, fMeth[%HomeObjectSymbol()]);
+  g.__proto__ = fMeth;
+  assertEquals(undefined, g[%HomeObjectSymbol()]);
+  var gMeth = g.toMethod(o1);
+  assertEquals(fMeth, gMeth.__proto__);
+  assertEquals(o1, gMeth[%HomeObjectSymbol()]);
+}());
+
+
+(function ToMethodBoundFunction() {
+  var o = {};
+  var p = {};
+
+
+  function f(x, y, z, w) {
+    assertEquals(o, this);
+    assertEquals(1, x);
+    assertEquals(2, y);
+    assertEquals(3, z);
+    assertEquals(4, w);
+    return x+y+z+w;
+  }
+
+  var fBound = f.bind(o, 1, 2, 3);
+  var fMeth = fBound.toMethod(p);
+  assertEquals(10, fMeth(4));
+  assertEquals(10, fMeth.call(p, 4));
+  var fBound1 = fBound.bind(o, 4);
+  assertEquals(10, fBound1());
+  var fMethBound = fMeth.bind(o, 4);
+  assertEquals(10, fMethBound());
+}());
+
+(function TestOptimized() {
+  function f(o) {
+    return o.x;
+  }
+  var o = {x : 15};
+  assertEquals(15, f(o));
+  assertEquals(15, f(o));
+  %OptimizeFunctionOnNextCall(f);
+  assertEquals(15, f(o));
+  var g = f.toMethod({});
+  var o1 = {y : 1024, x : "abc"};
+  assertEquals("abc", f(o1));
+  assertEquals("abc", g(o1));
+} ());
+
+
+(function TestPreserveProperties() {

[arv (Not doing code reviews), 2014/08/20 15:35:53]

This test is not right.

+  function f() { }
+  f.a = 1;
+  f.b = "abc";
+  var fc = {};
+  f.c = fc;
+  f[0] = "aaa";
+
+  var m = f.toMethod({});
+  assertEquals(1, m.a);
+  assertEquals("abc", m.b);
+  assertEquals(fc, m.c);
+  assertEquals("aaa", m[0]);
+
+  function g() { }
+  for (var k = 0; k < 10000; k++) {
+    g[k] = k/10000;
+  }
+  var m1 = g.toMethod({});
+  for (var k = 0; k < 10000; k++) {
+    assertEquals(k/10000, m1[k]);
+  }
+
+  function h() {}
+  var hProto = {}
+  h.prototype = hProto;
+  Object.defineProperty(h, "foo", { get: function() { return 42; } });
+  assertEquals(42, h.foo);
+  var m3 = h.toMethod({});
+  assertEquals(42, m3.foo);
+  assertEquals(hProto, m3.prototype);
+}());