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// Copyright 2013 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-generators
// Test basic generator syntax.
// Yield statements.
function* g() { yield 3; yield 4; }
// Yield expressions.
function* g() { (yield 3) + (yield 4); }
// You can have a generator in strict mode.
function* g() { "use strict"; yield 3; yield 4; }
// Generators can have return statements also, which internally parse to a kind
// of yield expression.
function* g() { yield 1; return; }
function* g() { yield 1; return 2; }
function* g() { yield 1; return 2; yield "dead"; }
// Generator expression.
(function* () { yield 3; });
// Named generator expression.
(function* g() { yield 3; });
// A generator without a yield is specified as causing an early error. This
// behavior is currently unimplemented. See
// https://bugs.ecmascript.org/show_bug.cgi?id=1283.
function* g() { }
// A YieldExpression in the RHS of a YieldExpression is currently specified as
// causing an early error. This behavior is currently unimplemented. See
// https://bugs.ecmascript.org/show_bug.cgi?id=1283.
function* g() { yield yield 1; }
function* g() { yield 3 + (yield 4); }
// Generator definitions with a name of "yield" are not specifically ruled out
// by the spec, as the `yield' name is outside the generator itself. However,
// in strict-mode, "yield" is an invalid identifier.
function* yield() { (yield 3) + (yield 4); }
assertThrows("function* yield() { \"use strict\"; (yield 3) + (yield 4); }",
SyntaxError);
// In classic mode, yield is a normal identifier, outside of generators.
function yield(yield) { yield: yield (yield + yield (0)); }
// Yield is always valid as a key in an object literal.
({ yield: 1 });
function* g() { yield ({ yield: 1 }) }
function* g() { yield ({ get yield() { return 1; }}) }
// Checks that yield is a valid label in classic mode, but not valid in a strict
// mode or in generators.
function f() { yield: 1 }
assertThrows("function f() { \"use strict\"; yield: 1 }", SyntaxError)
assertThrows("function* g() { yield: 1 }", SyntaxError)
// Yield is only a keyword in the body of the generator, not in nested
// functions.
function* g() { function f() { yield (yield + yield (0)); } }
// Yield needs a RHS.
assertThrows("function* g() { yield; }", SyntaxError);
// Yield in a generator is not an identifier.
assertThrows("function* g() { yield = 10; }", SyntaxError);
// Yield binds very loosely, so this parses as "yield (3 + yield 4)", which is
// invalid.
assertThrows("function* g() { yield 3 + yield 4; }", SyntaxError);
// Yield is still a future-reserved-word in strict mode
assertThrows("function f() { \"use strict\"; var yield = 13; }", SyntaxError);
// The name of the NFE is let-bound in G, so is invalid.
assertThrows("function* g() { yield (function yield() {}); }", SyntaxError);
// In generators, yield is invalid as a formal argument name.
assertThrows("function* g(yield) { yield (10); }", SyntaxError);
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