53 lines
2.1 KiB
TypeScript
53 lines
2.1 KiB
TypeScript
// @target: es6
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/* AssignmentPattern:
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* ObjectAssignmentPattern
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* ArrayAssignmentPattern
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* ArrayAssignmentPattern:
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* [Elision<opt> AssignmentRestElementopt ]
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* [AssignmentElementList]
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* [AssignmentElementList, Elision<opt> AssignmentRestElementopt ]
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* AssignmentElementList:
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* Elision<opt> AssignmentElement
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* AssignmentElementList, Elisionopt AssignmentElement
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* AssignmentElement:
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* LeftHandSideExpression Initialiseropt
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* AssignmentPattern Initialiseropt
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* AssignmentRestElement:
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* ... LeftHandSideExpression
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*/
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// In a destructuring assignment expression, the type of the expression on the right must be assignable to the assignment target on the left.
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// An expression of type S is considered assignable to an assignment target V if one of the following is true
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// V is an array assignment pattern, S is the type Any or an array-like type (section 3.3.2), and, for each assignment element E in V,
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// S is the type Any, or
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var [a0, a1]: any = undefined;
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var [a2 = false, a3 = 1]: any = undefined;
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// V is an array assignment pattern, S is the type Any or an array-like type (section 3.3.2), and, for each assignment element E in V,
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// S is a tuple- like type (section 3.3.3) with a property named N of a type that is assignable to the target given in E,
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// where N is the numeric index of E in the array assignment pattern, or
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var [b0, b1, b2] = [2, 3, 4];
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var [b3, b4, b5]: [number, number, string] = [1, 2, "string"];
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function foo() {
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return [1, 2, 3];
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}
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var [b6, b7] = foo();
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var [...b8] = foo();
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// S is not a tuple- like type and the numeric index signature type of S is assignable to the target given in E.
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var temp = [1,2,3]
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var [c0, c1] = [...temp];
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var [c2] = [];
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var [[[c3]], [[[[c4]]]]] = [[[]], [[[[]]]]]
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var [[c5], c6]: [[string|number], boolean] = [[1], true];
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var [, c7] = [1, 2, 3];
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var [,,, c8] = [1, 2, 3, 4];
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var [,,, c9] = [1, 2, 3, 4];
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var [,,,...c10] = [1, 2, 3, 4, "hello"];
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var [c11, c12, ...c13] = [1, 2, "string"];
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var [c14, c15, c16] = [1, 2, "string"]; |