then

Domenic Denicola domenic at domenicdenicola.com
Fri Nov 9 11:46:40 PST 2012


The recent promise discussion prompted me to recall the following musing/proposal from Kris Kowal:

https://github.com/kriskowal/q/wiki/On-Exceptions

In short, there's a common code pattern that you can do with promises that you can't do with synchronous code. The proposal is for a language extension `then` that would allow synchronous code like this:

var info, processed;
try {
    info = JSON.parse(json);
} catch (exception) {
    console.log("Information JSON malformed.");
} then {
    processed = process(info);
} catch (exception) {
    console.log("Error processing information.");
}

Since seeing this, I've run into a lot of situations where a `then` would come in handy. I wanted to see if anyone else thought this was a great idea, and if it has any chance as an ES7-level proposal.



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