michael@0: // This file was written by Andy Wingo <wingo@igalia.com> and originally
michael@0: // contributed to V8 as generators-parsing.js, available here:
michael@0: //
michael@0: // http://code.google.com/p/v8/source/browse/branches/bleeding_edge/test/mjsunit/harmony/generators-parsing.js
michael@0: 
michael@0: function assertSyntaxError(str) {
michael@0:     var msg;
michael@0:     var evil = eval;
michael@0:     try {
michael@0:         // Non-direct eval.
michael@0:         evil(str);
michael@0:     } catch (exc) {
michael@0:         if (exc instanceof SyntaxError)
michael@0:             return;
michael@0:         msg = "Assertion failed: expected SyntaxError, got " + exc;
michael@0:     }
michael@0:     if (msg === undefined)
michael@0:         msg = "Assertion failed: expected SyntaxError, but no exception thrown";
michael@0:     throw new Error(msg + " - " + str);
michael@0: }
michael@0: 
michael@0: // Yield statements.
michael@0: function* g() { yield 3; yield 4; }
michael@0: 
michael@0: // Yield expressions.
michael@0: function* g() { (yield 3) + (yield 4); }
michael@0: 
michael@0: // You can have a generator in strict mode.
michael@0: function* g() { "use strict"; yield 3; yield 4; }
michael@0: 
michael@0: // Generators can have return statements also, which internally parse to a kind
michael@0: // of yield expression.
michael@0: function* g() { yield 1; return; }
michael@0: function* g() { yield 1; return 2; }
michael@0: function* g() { yield 1; return 2; yield "dead"; }
michael@0: 
michael@0: // Generator expression.
michael@0: (function* () { yield 3; });
michael@0: 
michael@0: // Named generator expression.
michael@0: (function* g() { yield 3; });
michael@0: 
michael@0: // Generators do not have to contain yield expressions.
michael@0: function* g() { }
michael@0: 
michael@0: // YieldExpressions can occur in the RHS of a YieldExpression.
michael@0: function* g() { yield yield 1; }
michael@0: function* g() { yield 3 + (yield 4); }
michael@0: 
michael@0: // Generator definitions with a name of "yield" are not specifically ruled out
michael@0: // by the spec, as the `yield' name is outside the generator itself.  However,
michael@0: // in strict-mode, "yield" is an invalid identifier.
michael@0: function* yield() { (yield 3) + (yield 4); }
michael@0: assertSyntaxError("function* yield() { 'use strict'; (yield 3) + (yield 4); }");
michael@0: 
michael@0: // In classic mode, yield is a normal identifier, outside of generators.
michael@0: function yield(yield) { yield: yield (yield + yield (0)); }
michael@0: 
michael@0: // Yield is always valid as a key in an object literal.
michael@0: ({ yield: 1 });
michael@0: function* g() { yield ({ yield: 1 }) }
michael@0: function* g() { yield ({ get yield() { return 1; }}) }
michael@0: 
michael@0: // Yield is a valid property name.
michael@0: function* g(obj) { yield obj.yield; }
michael@0: 
michael@0: // Checks that yield is a valid label in classic mode, but not valid in a strict
michael@0: // mode or in generators.
michael@0: function f() { yield: 1 }
michael@0: assertSyntaxError("function f() { 'use strict'; yield: 1 }")
michael@0: assertSyntaxError("function* g() { yield: 1 }")
michael@0: 
michael@0: // Yield is only a keyword in the body of the generator, not in nested
michael@0: // functions.
michael@0: function* g() { function f(yield) { yield (yield + yield (0)); } }
michael@0: 
michael@0: // Yield needs a RHS.
michael@0: assertSyntaxError("function* g() { yield; }");
michael@0: 
michael@0: // Yield in a generator is not an identifier.
michael@0: assertSyntaxError("function* g() { yield = 10; }");
michael@0: 
michael@0: // Yield binds very loosely, so this parses as "yield (3 + yield 4)", which is
michael@0: // invalid.
michael@0: assertSyntaxError("function* g() { yield 3 + yield 4; }");
michael@0: 
michael@0: // Yield is still a future-reserved-word in strict mode
michael@0: assertSyntaxError("function f() { 'use strict'; var yield = 13; }");
michael@0: 
michael@0: // The name of the NFE is let-bound in G, so is invalid.
michael@0: assertSyntaxError("function* g() { yield (function yield() {}); }");
michael@0: 
michael@0: // In generators, yield is invalid as a formal argument name.
michael@0: assertSyntaxError("function* g(yield) { yield (10); }");
michael@0: 
michael@0: if (typeof reportCompare == "function")
michael@0:     reportCompare(true, true);