1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
=== tests/cases/compiler/genericRestTypes.ts ===
// Repro from #25793
// Gets the parameters of a function type as a tuple
// Removes the first element from a tuple
type Tail<T extends any[]> = ((...args: T) => any) extends ((head: any, ...tail: infer U) => any) ? U : never;
>Tail : Symbol(Tail, Decl(genericRestTypes.ts, 0, 0))
>T : Symbol(T, Decl(genericRestTypes.ts, 4, 10))
>args : Symbol(args, Decl(genericRestTypes.ts, 4, 31))
>T : Symbol(T, Decl(genericRestTypes.ts, 4, 10))
>head : Symbol(head, Decl(genericRestTypes.ts, 4, 61))
>tail : Symbol(tail, Decl(genericRestTypes.ts, 4, 71))
>U : Symbol(U, Decl(genericRestTypes.ts, 4, 86))
>U : Symbol(U, Decl(genericRestTypes.ts, 4, 86))
type MyFunctionType = (foo: number, bar: string) => boolean;
>MyFunctionType : Symbol(MyFunctionType, Decl(genericRestTypes.ts, 4, 110))
>foo : Symbol(foo, Decl(genericRestTypes.ts, 6, 23))
>bar : Symbol(bar, Decl(genericRestTypes.ts, 6, 35))
type Explicit = (...args: Tail<Parameters<MyFunctionType>>) => ReturnType<MyFunctionType>; // (bar: string) => boolean
>Explicit : Symbol(Explicit, Decl(genericRestTypes.ts, 6, 60))
>args : Symbol(args, Decl(genericRestTypes.ts, 8, 17))
>Tail : Symbol(Tail, Decl(genericRestTypes.ts, 0, 0))
>Parameters : Symbol(Parameters, Decl(lib.es5.d.ts, --, --))
>MyFunctionType : Symbol(MyFunctionType, Decl(genericRestTypes.ts, 4, 110))
>ReturnType : Symbol(ReturnType, Decl(lib.es5.d.ts, --, --))
>MyFunctionType : Symbol(MyFunctionType, Decl(genericRestTypes.ts, 4, 110))
type Bind1<T extends (head: any, ...tail: any[]) => any> = (...args: Tail<Parameters<T>>) => ReturnType<T>;
>Bind1 : Symbol(Bind1, Decl(genericRestTypes.ts, 8, 90))
>T : Symbol(T, Decl(genericRestTypes.ts, 10, 11))
>head : Symbol(head, Decl(genericRestTypes.ts, 10, 22))
>tail : Symbol(tail, Decl(genericRestTypes.ts, 10, 32))
>args : Symbol(args, Decl(genericRestTypes.ts, 10, 60))
>Tail : Symbol(Tail, Decl(genericRestTypes.ts, 0, 0))
>Parameters : Symbol(Parameters, Decl(lib.es5.d.ts, --, --))
>T : Symbol(T, Decl(genericRestTypes.ts, 10, 11))
>ReturnType : Symbol(ReturnType, Decl(lib.es5.d.ts, --, --))
>T : Symbol(T, Decl(genericRestTypes.ts, 10, 11))
type Generic = Bind1<MyFunctionType>; // (bar: string) => boolean
>Generic : Symbol(Generic, Decl(genericRestTypes.ts, 10, 107))
>Bind1 : Symbol(Bind1, Decl(genericRestTypes.ts, 8, 90))
>MyFunctionType : Symbol(MyFunctionType, Decl(genericRestTypes.ts, 4, 110))
|
