Control flow to try/error if result got?

[benpptung]

Hi ... I love async!! and use a lot of it, especially, I love compose.
Thank you for the great module!! However, I cannot find a control flow to try/error the callback, is there any control flow function can do the following thing?

That said, I have fn1, fn2, fn3, all of them will callback an error or result, if fn1 get the result, then the control flow end, or continue to fn2, then fn3. For example, it might look like:

async.try( [ 
  function(next){
     do_first_try(param, function(err, res){
         if (err) return next(err);
         next(null, res); /// the control flow end, because we have result now
     }
  }, 
  function(next){
    do_second_try(param, function(err, res){
        if (err) return next(err);
        next(null, res); /// the control flow end, because we have result now
    }
  }, 
  function(next){
    do_third_try(param, function(err, res){
        if (err) return next(err);
        next(null, res); /// the control flow end, because we have result now
    }
  },], function( err, result) {
       /// get the result whatever it comes from first try or third try, or err if no result
})

[aearly]

Interesting, it's kind of like series, except with the inverse of how it handles errors. It definitely could come in handy.

[benpptung]

yes :) in fact, I am using series doing this now, done(res) to stop the try/error and return the result or done(null)to continue the next try, but it is looking like an anti-pattern to callback.

[knoid]

+1
I'll try using series for now. Thanks for the tip.

[aearly]

After further thought -- is this any different from retry? This allows you to have a unique function for every try, but is that actually useful? This is also similar to #568

[benpptung]

I think retry is doing the same task to get a successful response from task no more than specific times before returning an error. . e.g. ping a server alive or not. I think it is different from the idea of try/error, in which, we can try different ways to get a successful result. e.g. the typical way to get XMLHttpRequest in front-end.

[megawac]

Yeah 👍 I'd like this.