qrepeat

Fast iteration of async functions.

const qrepeat = require('qrepeat');

function repeatThreeTimes( func ) {
    var count = 0;
    qrepeat.repeatUntil(
        function(next) {
            console.log(++count);
            next(null, count >= 3);
        },
        function(err) {
            console.log('Done.');
        }
    );
}
repeatThreeTimes();
// => 1
//    2
//    3
//    Done.

Testing

Qrepeat tries to keep the call overhead low, to be efficient for even short loops. Tests and benchmark in the repo.

qtimeit=0.22.0 node=11.8.0 v8=7.0.276.38-node.16 platform=linux kernel=4.9.0-0.bpo.4-amd64 up_threshold=false
arch=ia32 mhz=4186 cpuCount=8 cpu="Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz"
name                          speed           rate
async.whilst             13,162,223 ops/sec   1000 >>>>>
async.doUntil             9,749,568 ops/sec    741 >>>>
qrepeat.repeatUntil      60,278,971 ops/sec   4580 >>>>>>>>>>>>>>>>>>>>>>>
qrepeat.repeatWhile      37,007,516 ops/sec   2812 >>>>>>>>>>>>>>
aflow.repeatUntil        49,575,938 ops/sec   3767 >>>>>>>>>>>>>>>>>>>
aflow.repeatWhile        18,314,612 ops/sec   1391 >>>>>>>

API

repeatUntil( fn, callback(err) )

Repeatedly call fn(cb) until it returns a truthy value to its callback. Stops if fn throws. Note: because callback runs in the same try/catch as fn, errors thrown by callback are also caught and routed to the callback.

Equivalent to the pseudocode

while (!fn()) ;

repeatWhile( testFn, fn, callback(err) )

While testFn() returns truthy, repeatedly call fn(cb). Stops if fn throws. Note: because callback runs in the same try/catch as fn, errors thrown by callback are also caught and routed to the callback.

Equivalent to the pseudocode

while (testFn()) fn();

Change Log

• 0.8.1 - yield to event loop more frequently
• 0.8.0 - first published version