Hi Bruno, On Apr 28, 2012, at 11:14 AM, Bruno Jouhier wrote:
> Neither! > > I think that question should be callbacks vs. events vs. streams: > • Callback: called only once, when the function is done, to return > result (optional) or error. > • Event: called repeatedly by the function to notify its listeners. Can > be used to send intermediate results as they come. > • Stream: higher level concept based on events, with standardized event > types (data, end, error, drain) and standardized API (pause, resume, write, > ..). > So, assuming prime computation is asynchronous: > > • If the function computes the N first primes and returns them all at > once, it should use a callback. > • If the function returns the primes one by one, it should use events. > It may also use a stream but that seems a bit over-engineered. Good, yes, that's the way it is in node, but it does not explain *why* it is so. .readFile() could as well deliver the chunks to the cb as they're read from disk, and to use it you'd need to write just one line: fs.readFile(path, cb); While to do the same with an evented interface there's a lot of boilerplate to write, and an extra object to create: reader= new fileReaderConstructor(path); reader.on('data', cb); reader.on('end', endCB); reader.on('error', errorCB); It seems to me that the former is more functional and makes good use of closures (*), while the latter is the approach a classic OOP programmer would tend to write instead. (*)In JavaScript we don't need to create objects to save state. -- Jorge. -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups "nodejs" group. To post to this group, send email to nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en