/**

• callbag-map

• ---

• Callbag operator that applies a transformation on data passing through it.
• Works on either pullable or listenable sources.
• npm install callbag-map
• Example:

• const fromIter = require('callbag-from-iter');

• const iterate = require('callbag-iterate');

• const map = require('callbag-map');

• const source = map(x => x * 0.1)(fromIter([10,20,30,40]));

• iterate(x => console.log(x))(source); // 1

•                                       // 2

•                                       // 3

•                                       // 4

*/

const map = f => source => (start, sink) => { if (start !== 0) return; source(0, (t, d) => { sink(t, t === 1 ? f(d) : d) }); };

module.exports = map;