export function isFunction(x: any): x is Function {
    return typeof x === 'function';
}

export const any = (fn: Function, list: any[]) => {
    let idx = 0;
    while (idx < list.length) {
        if (fn(list[idx])) {
            return true;
        }
        idx += 1;
    }
    return false;
};
export const identity = x => x;

export const isNill = x => x == null;

export const difference = (first: any[], second: any[]) =>
    first.filter(item => !(<any>second).some(secondItem=>secondItem==item));

export const allPass = preds => (...args) => {
    let idx = 0;
    const len = preds.length;
    while (idx < len) {
        if (!preds[idx].apply(this, args)) {
            return false;
        }
        idx += 1;
    }
    return true;
};