sum<U extends num> method

U sum<U extends num>([ TFuncMapper<T, U>? funcMapper ])

Implementation

U sum<U extends num>([ TFuncMapper<T, U>? funcMapper ]) {
	if (funcMapper == null) {
		if (T == num || T == int || T == double) {
			return this.sum((x) => x as U);
		}
		throw "a mapper was not provided but the values' type is not numeric";
	}

	return this.reduceTo<U>((U total, T cur) => (total + funcMapper(cur)) as U, 0 as U);
}