syzer · November 16, 2015 16:14
diff --git a/map_wihout_loop_ifs.js b/map_wihout_loop_ifs.js
 // here condR === undefined
 const falsy = (condL, condR) => condL !== condR;

 const map = (fn, [first, ...rest]) =>
    (falsy(first) && []) && [fn(first), ...map(fn, rest)];

 console.log(':)', map((x) => (x + x), [1, 2, 3]));
	// here condR === undefined
	const falsy = (condL, condR) => condL !== condR;

	const map = (fn, [first, ...rest]) =>
	(falsy(first) && []) && [fn(first), ...map(fn, rest)];

	console.log(':)', map((x) => (x + x), [1, 2, 3]));