callbag-graceful v1.0.0

'use strict';

/**

• callbag-graceful

• ---

• Callbag operator for graceful error handling.
• When an Error occurs while calling the sink, this operator terminates both
• the talkback and the sink. Errors thrown while terminating the sink are not
• catched since terminating it twice is forbidden by the spec.
• Also, note that the operator can only catch errors thrown synchronously when
• calling the sink. Errors thrown in asynchronous events must still be handled
• manually.
• Works on either pullable or listenable sources.
• Installation:
• npm install callbag-graceful
• Example:

• import graceful from 'callbag-graceful';

• import map from 'callbag-map';

• import pipe from 'callbag-pipe';

• import of from 'callbag-of';

• import subscribe from 'callbag-subscribe';

• pipe(

•   of(0, 1, 2, 'foo', 3),

•   graceful,

•   map(x => {

•     if (typeof x === 'number') return x;

•     else throw new Error('Not a number');

•   }),

•   subscribe({

•     next: x => console.log(`Next: ${x}`),

•     error: e => console.log(`Error: ${e.message}`),

•     complete: () => console.log('Complete')

•   })

• );                                          // Next: 0

•                                             // Next: 1

•                                             // Next: 2

•                                             // Error: Not a number

  */

var readme = source => (start, sink) => { if (start !== 0) return; let talkback; source(0, (t, d) => { if (t === 0) talkback = d; if (t === 2) { sink(t, d); return; } try { sink(t, d); } catch (e) { talkback(2); sink(2, e); } }); };

module.exports = readme;