typescript - Creating a version of a generic function with the type 'clamped' -

let's have function returns type parameterized generic. i'm going using function lot. of time i'll using 1 particular type - number. convenience, nice have alias of function numbers.

toy example:

function arraymaker<t>() : array<t> {     return new array<t>(); } let numericalarraymaker: () => array<number> = arraymaker<number>; 

but typescript compiler complains last line, thinking i'm assigning type number[] numericalarraymaker.

i'm confused why fails, because can assign function (without generic type) variable:

function foo() { return 0; } let foo2 = foo; 

... , can assign type (with generic) variable:

type numericalarray = myarray<number>; 

is there different syntax i'm trying do?

(i understand make example work using factory function returning "arraymakers", becomes deal more verbose, , leads code duplication if function takes arguments.)

all need save reference of arraymaker variable type want:

function arraymaker<t>() : array<t> {     return new array<t>(); }  let numericalarraymaker: () => array<number> = arraymaker let mynums: number[] = numericalarraymaker(); 

you can not use generics function signature if you're not calling it, like: arraymaker<number>, makes no real sense.

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edit

i'm not sure why compiler doesn't complain about

let numericalarraymaker: (string) => number[] = arraymaker; 

it might bug, or maybe there's better explanation eludes me, if open issue please post url comment i'd flow on that.

you can go around issue though this:

type arraymaker<t> = (value: t) => t[];  let numericalarraymaker: arraymaker<number> = arraymaker; let mynums: number[] = numericalarraymaker("foo"); // error 

as why this:

let = arraymaker<number>; 

doesn't make sense, assigning reference arraymaker function variable a, there's no such thing generics in js there's no meaning arraymaker<number>.
want casting:

let = arraymaker arraymaker<number>; 

maybe clearer classes:

class a<t> {}  let a1 = a<number>; // error let a2 = a<number>; / ok 

this works with:

type numericalarray = myarray<number>; 

because here you're dealing type of myarray , not actual function.

this brings else believe in:
don't write code in typescript typescript, if compiled code wrote doesn't anything, written ts compiling, it's bad idea.

i think it's best go with:

let mynums: number[] = arraymaker(4);