race-promises-pool

1.js

async function racePromisesPool([ ...prs ] = []) {
   var raceWon = false;
   var prListeners = prs.map(function listen(pr,idx){
      return pr.then(function t(v){
         if (!raceWon) {
            raceWon = true;
            prs.splice(idx,1);  // remove the promise from the pool since it won the race
            return v;
         }
      });
   });
   return [ prs, await Promise.race(prListeners) ];
}

2.js

main();

// *******************************************

async function main() {
   // pull file responses ASAP and print them out as they arrive
   for await (let text of loadFiles([
      "https://url.tld/file1",
      "https://url.tld/file2",
      "https://url.tld/file3"
   ])) {
      console.log(text);
   }
}

async function *loadFiles(files) {
   var pool = files.map(getFile);
   
   while (pool.length > 0) {
      // get the next-ready promise from the pool
      let nextResponse;
      [ pool, nextResponse ] = await racePromisesPool(pool);

      // push response out through iterator
      yield nextResponse;
   }
}

function getFile(file) {
   return new Promise(function c(resolve){
      ajax(file,resolve);
   });
}

Hello @getify,
dope!
How useful this could be in a project ? I still don't see any use case for it