TypeScript/tests/baselines/reference/destructuringArrayBindingPatternAndAssignment1ES6.types
2015-04-16 19:20:08 -07:00

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=== tests/cases/conformance/es6/destructuring/destructuringArrayBindingPatternAndAssignment1ES6.ts ===
/* AssignmentPattern:
* ObjectAssignmentPattern
* ArrayAssignmentPattern
* ArrayAssignmentPattern:
* [Elision<opt> AssignmentRestElementopt ]
* [AssignmentElementList]
* [AssignmentElementList, Elision<opt> AssignmentRestElementopt ]
* AssignmentElementList:
* Elision<opt> AssignmentElement
* AssignmentElementList, Elisionopt AssignmentElement
* AssignmentElement:
* LeftHandSideExpression Initialiseropt
* AssignmentPattern Initialiseropt
* AssignmentRestElement:
* ... LeftHandSideExpression
*/
// In a destructuring assignment expression, the type of the expression on the right must be assignable to the assignment target on the left.
// An expression of type S is considered assignable to an assignment target V if one of the following is true
// 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,
// S is the type Any, or
var [a0, a1]: any = undefined;
>a0 : any
>a1 : any
>undefined : undefined
var [a2 = false, a3 = 1]: any = undefined;
>a2 : boolean
>false : boolean
>a3 : number
>1 : number
>undefined : undefined
// 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,
// 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,
// where N is the numeric index of E in the array assignment pattern, or
var [b0, b1, b2] = [2, 3, 4];
>b0 : number
>b1 : number
>b2 : number
>[2, 3, 4] : [number, number, number]
>2 : number
>3 : number
>4 : number
var [b3, b4, b5]: [number, number, string] = [1, 2, "string"];
>b3 : number
>b4 : number
>b5 : string
>[1, 2, "string"] : [number, number, string]
>1 : number
>2 : number
>"string" : string
function foo() {
>foo : () => number[]
return [1, 2, 3];
>[1, 2, 3] : number[]
>1 : number
>2 : number
>3 : number
}
var [b6, b7] = foo();
>b6 : number
>b7 : number
>foo() : number[]
>foo : () => number[]
var [...b8] = foo();
>b8 : number[]
>foo() : number[]
>foo : () => number[]
// S is not a tuple- like type and the numeric index signature type of S is assignable to the target given in E.
var temp = [1,2,3]
>temp : number[]
>[1,2,3] : number[]
>1 : number
>2 : number
>3 : number
var [c0, c1] = [...temp];
>c0 : number
>c1 : number
>[...temp] : number[]
>...temp : number
>temp : number[]
var [c2] = [];
>c2 : any
>[] : undefined[]
var [[[c3]], [[[[c4]]]]] = [[[]], [[[[]]]]]
>c3 : any
>c4 : any
>[[[]], [[[[]]]]] : [[undefined[]], [[[undefined[]]]]]
>[[]] : [undefined[]]
>[] : undefined[]
>[[[[]]]] : [[[undefined[]]]]
>[[[]]] : [[undefined[]]]
>[[]] : [undefined[]]
>[] : undefined[]
var [[c5], c6]: [[string|number], boolean] = [[1], true];
>c5 : string | number
>c6 : boolean
>[[1], true] : [[number], boolean]
>[1] : [number]
>1 : number
>true : boolean
var [, c7] = [1, 2, 3];
> : undefined
>c7 : number
>[1, 2, 3] : [number, number, number]
>1 : number
>2 : number
>3 : number
var [,,, c8] = [1, 2, 3, 4];
> : undefined
> : undefined
> : undefined
>c8 : number
>[1, 2, 3, 4] : [number, number, number, number]
>1 : number
>2 : number
>3 : number
>4 : number
var [,,, c9] = [1, 2, 3, 4];
> : undefined
> : undefined
> : undefined
>c9 : number
>[1, 2, 3, 4] : [number, number, number, number]
>1 : number
>2 : number
>3 : number
>4 : number
var [,,,...c10] = [1, 2, 3, 4, "hello"];
> : undefined
> : undefined
> : undefined
>c10 : (string | number)[]
>[1, 2, 3, 4, "hello"] : (string | number)[]
>1 : number
>2 : number
>3 : number
>4 : number
>"hello" : string
var [c11, c12, ...c13] = [1, 2, "string"];
>c11 : string | number
>c12 : string | number
>c13 : (string | number)[]
>[1, 2, "string"] : (string | number)[]
>1 : number
>2 : number
>"string" : string
var [c14, c15, c16] = [1, 2, "string"];
>c14 : number
>c15 : number
>c16 : string
>[1, 2, "string"] : [number, number, string]
>1 : number
>2 : number
>"string" : string