Kal – a clean JavaScript alternative without callbacks

Post by tlb » Sat, Aug 17, 2013, 2:34 AM UTC

rzimmerman wrote: post #53

tlb wrote: post #46

I'm puzzled by the bootstrapping process. It's written in Kal itself, and you distributed compiled code as JS. Do you have a way of re-boostrapping from only the source in github?

The only way to re-bootstrap is to download a compiled (JS) release from npm, then use that to compile the .kal source in the git repository. Then you can use your newly compiled version of kal to recompile itself. This is how I create the npm releases. It's not turtles all the way down, though. If you look way back, the 0.1ish releases of the compiler were written in CoffeeScript. I ported the compiler source over f…

Post by aaronharder » Sat, Aug 17, 2013, 2:55 AM UTC

ilaksh wrote: post #63

ToffeeScript is very similar but better. https://github.com/jiangmiao/toffee-script

Post by rzimmerman » Sat, Aug 17, 2013, 2:57 AM UTC

pcj wrote: post #58

rybosome wrote: post #41

It's remarkable how similar this code looks to the monadic way of doing it. For this Kal code... task getUserFriends(userName) wait for user from db.users.findOne {name:userName} wait for friends from db.friends.find {userId:user.id} if user.type is 'power user' for parallel friend in friends wait for friendsOfFriend from db.friends.find friend for newFriend in friendsOfFriend friends.push newFriend unless newFriend…

This is beautiful work! I see small shades of inspiration from the .Net TPL[1] and the more recent async-await paradigm[2] in C#. But, this is way more concise and beautiful implementation :-) [1] - http://msdn.microsoft.com/en-us/library/vstudio/system.threa... [2] - http://msdn.microsoft.com/en-us/library/vstudio/hh191443.asp... and http://msdn.microsoft.com/en-us/library/vstudio/hh156528.asp...

Post by tlrobinson » Sat, Aug 17, 2013, 3:32 AM UTC

mjackson wrote: post #49

For the curious, the equivalent example from the OP using promises[1]: function getUserFriends(userName) { return db.users.findOne({ name: userName }).then(function (user) { return db.friends.find({ userId: user.id }); }); } [1]: http://promises-aplus.github.io/promises-spec/

    getUserFriends = (userName) ->
      db.users.findOne(name: userName).then (user) ->
        db.friends.find userId: user.id

    getUserFriends = (userName) ->
      db.users.findOne(name: userName)
        .then (user) ->
          db.friends.find userId: user.id
        .then(function (friends) ->
          somethingAsync(friends)

    getUserFriends = (userName) ->
      QStep(
        ->
          db.users.findOne name: userName
        (user) ->
          db.friends.find userId: user.id
        (friends) ->
          somethingAsync friends
      )

Post by halacsy » Sat, Aug 17, 2013, 3:42 AM UTC