Function undefinedMap

shared/src/utility.ts:23–31

(
	t: T | undefined,
	f: (_: T) => R,
)

}

export function undefinedMap<T, R>(
	t: T | undefined,
	f: (_: T) => R,
): R | undefined {
	if (t === undefined) {
		return t as undefined
	}
	return f(t)
}

export function nullMap<T, R>(t: T | null, f: (_: T) => R): R | null {
	if (t === null) {