95145fa826
This patch moves the semantics of 'const' in sloppy mode to match those in strict mode, that is, const makes lexical (let-like) bindings, must have an initializer, and does not create properties of the global object. R=adamk LOG=Y BUG=v8:3305 CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng;tryserver.blink:linux_blink_rel Review URL: https://codereview.chromium.org/1571873004 Cr-Commit-Position: refs/heads/master@{#33218}
95 lines
2.7 KiB
JavaScript
95 lines
2.7 KiB
JavaScript
// Copyright 2008 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: --legacy-const
|
|
|
|
// const variables should be read-only
|
|
const c = 42;
|
|
c = 87;
|
|
assertEquals(42, c);
|
|
|
|
|
|
// const variables are not behaving like other JS variables when it comes
|
|
// to scoping - in fact they behave more sanely. Inside a 'with' they do
|
|
// not interfere with the 'with' scopes.
|
|
|
|
(function () {
|
|
with ({ x: 42 }) {
|
|
const x = 7;
|
|
}
|
|
x = 5;
|
|
assertEquals(7, x);
|
|
})();
|
|
|
|
|
|
// const variables may be declared but never initialized, in which case
|
|
// their value is undefined.
|
|
|
|
(function (sel) {
|
|
if (sel == 0)
|
|
with ({ x: 42 }) {
|
|
const x;
|
|
}
|
|
else
|
|
x = 3;
|
|
x = 5;
|
|
assertTrue(typeof x == 'undefined');
|
|
})(1);
|
|
|
|
|
|
// const variables may be initialized to undefined.
|
|
(function () {
|
|
with ({ x: 42 }) {
|
|
const x = undefined;
|
|
}
|
|
x = 5;
|
|
assertTrue(typeof x == 'undefined');
|
|
})();
|
|
|
|
|
|
// const variables may be accessed in inner scopes like any other variable.
|
|
(function () {
|
|
function bar() {
|
|
assertEquals(7, x);
|
|
}
|
|
with ({ x: 42 }) {
|
|
const x = 7;
|
|
}
|
|
x = 5
|
|
bar();
|
|
})();
|
|
|
|
|
|
// const variables may be declared via 'eval'
|
|
(function () {
|
|
with ({ x: 42 }) {
|
|
eval('const x = 7');
|
|
}
|
|
x = 5;
|
|
assertEquals(7, x);
|
|
})();
|