function tap(tapper) {
    return function* (it) {
        let index = 0;
        for (const value of it) {
            tapper(value, index);
            yield value;
            index = index + 1;
        }
    };
}
function tap(tapper) {
    return function* (it) {
        let index = 0;
        for (const value of it) {
            tapper(value, index);
            yield value;
            index = index + 1;
        }
    };
}
function tap ( tapper ) { return function * ( it ) { let index = 0 ; for ( const value of it ) { tapper ( value , index ) ; yield value ; index = index + 1 ; } } ; }
Yield the original sequence unmodified, calling the tapper on every item in the sequence
Yield the original sequence unmodified calling the tapper on every item in the sequence