38 lines
901 B
TypeScript
38 lines
901 B
TypeScript
|
import { pipe } from "./composition.ts";
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Get a function to check that inputs are instances of a given type
|
||
|
|
*/
|
||
|
|
export function isinstance<T, S extends T>(
|
||
|
|
ref: { new (...args: any[]): T },
|
||
|
|
): (input: S) => input is Extract<T, S> {
|
||
|
|
return (x): x is Extract<T, S> => x instanceof ref;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Check that a value is not null, throwing an error if it is
|
||
|
|
*/
|
||
|
|
export function nn<T>(value: T | null): T {
|
||
|
|
if (value === null) {
|
||
|
|
throw new Error("null value");
|
||
|
|
} else {
|
||
|
|
return value;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Check that a value is not undefined, throwing an error if it is
|
||
|
|
*/
|
||
|
|
export function nu<T>(value: T | undefined): T {
|
||
|
|
if (typeof value === "undefined") {
|
||
|
|
throw new Error("undefined value");
|
||
|
|
} else {
|
||
|
|
return value;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Check that a value is not null nor undefined, throwing an error if it is
|
||
|
|
*/
|
||
|
|
export const nnu: <T>(value: T | null | undefined) => T = pipe(nn, nu);
|