Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 1 | // Copyright 2013 the V8 project authors. All rights reserved. |
| 2 | // Redistribution and use in source and binary forms, with or without |
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| 8 | // * Redistributions in binary form must reproduce the above |
| 9 | // copyright notice, this list of conditions and the following |
| 10 | // disclaimer in the documentation and/or other materials provided |
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Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 28 | // Flags: --ignition-generators |
| 29 | |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 30 | // Test basic generator syntax. |
| 31 | |
| 32 | // Yield statements. |
| 33 | function* g() { yield 3; yield 4; } |
| 34 | |
| 35 | // Yield expressions. |
| 36 | function* g() { (yield 3) + (yield 4); } |
| 37 | |
| 38 | // Yield without a RHS. |
| 39 | function* g() { yield; } |
| 40 | function* g() { yield } |
| 41 | function* g() { |
| 42 | yield |
| 43 | } |
| 44 | function* g() { (yield) } |
| 45 | function* g() { [yield] } |
| 46 | function* g() { {yield} } |
| 47 | function* g() { yield, yield } |
| 48 | function* g() { yield; yield } |
| 49 | function* g() { (yield) ? yield : yield } |
| 50 | function* g() { |
| 51 | (yield) |
| 52 | ? yield |
| 53 | : yield |
| 54 | } |
| 55 | |
| 56 | // If yield has a RHS, it needs to start on the same line. The * in a |
| 57 | // yield* counts as starting the RHS. |
| 58 | function* g() { |
| 59 | yield * |
| 60 | foo |
| 61 | } |
| 62 | assertThrows("function* g() { yield\n* foo }", SyntaxError); |
| 63 | assertEquals(undefined, |
| 64 | (function*(){ |
| 65 | yield |
| 66 | 3 |
| 67 | })().next().value); |
| 68 | |
| 69 | // A YieldExpression is not a LogicalORExpression. |
| 70 | assertThrows("function* g() { yield ? yield : yield }", SyntaxError); |
| 71 | |
| 72 | // You can have a generator in strict mode. |
| 73 | function* g() { "use strict"; yield 3; yield 4; } |
| 74 | |
| 75 | // Generators can have return statements also, which internally parse to a kind |
| 76 | // of yield expression. |
| 77 | function* g() { yield 1; return; } |
| 78 | function* g() { yield 1; return 2; } |
| 79 | function* g() { yield 1; return 2; yield "dead"; } |
| 80 | |
| 81 | // Generator expression. |
| 82 | (function* () { yield 3; }); |
| 83 | |
| 84 | // Named generator expression. |
| 85 | (function* g() { yield 3; }); |
| 86 | |
| 87 | // You can have a generator without a yield. |
| 88 | function* g() { } |
| 89 | |
| 90 | // A YieldExpression is valid as the RHS of a YieldExpression. |
| 91 | function* g() { yield yield 1; } |
| 92 | function* g() { yield 3 + (yield 4); } |
| 93 | |
| 94 | // Generator definitions with a name of "yield" are not specifically ruled out |
| 95 | // by the spec, as the `yield' name is outside the generator itself. However, |
| 96 | // in strict-mode, "yield" is an invalid identifier. |
| 97 | function* yield() { (yield 3) + (yield 4); } |
| 98 | assertThrows("function* yield() { \"use strict\"; (yield 3) + (yield 4); }", |
| 99 | SyntaxError); |
| 100 | |
| 101 | // In sloppy mode, yield is a normal identifier, outside of generators. |
| 102 | function yield(yield) { yield: yield (yield + yield (0)); } |
| 103 | |
| 104 | // Yield is always valid as a key in an object literal. |
| 105 | ({ yield: 1 }); |
| 106 | function* g() { yield ({ yield: 1 }) } |
| 107 | function* g() { yield ({ get yield() { return 1; }}) } |
| 108 | |
| 109 | // Checks that yield is a valid label in sloppy mode, but not valid in a strict |
| 110 | // mode or in generators. |
| 111 | function f() { yield: 1 } |
| 112 | assertThrows("function f() { \"use strict\"; yield: 1 }", SyntaxError) |
| 113 | assertThrows("function* g() { yield: 1 }", SyntaxError) |
| 114 | |
| 115 | // Yield is only a keyword in the body of the generator, not in nested |
| 116 | // functions. |
| 117 | function* g() { function f() { yield (yield + yield (0)); } } |
| 118 | |
| 119 | // Yield in a generator is not an identifier. |
| 120 | assertThrows("function* g() { yield = 10; }", SyntaxError); |
| 121 | |
| 122 | // Yield binds very loosely, so this parses as "yield (3 + yield 4)", which is |
| 123 | // invalid. |
| 124 | assertThrows("function* g() { yield 3 + yield 4; }", SyntaxError); |
| 125 | |
| 126 | // Yield is still a future-reserved-word in strict mode |
| 127 | assertThrows("function f() { \"use strict\"; var yield = 13; }", SyntaxError); |
| 128 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 129 | // The name of the NFE is bound in the generator expression, so is invalid. |
| 130 | assertThrows("function f() { (function* yield() {}); }", SyntaxError); |
Ben Murdoch | b8a8cc1 | 2014-11-26 15:28:44 +0000 | [diff] [blame] | 131 | |
| 132 | // In generators, yield is invalid as a formal argument name. |
| 133 | assertThrows("function* g(yield) { yield (10); }", SyntaxError); |