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The "try coffeescript" demo (http://jashkenas.github.com/coffee-script/ http://jashkenas.github.com/coffee-script/) is really cool. It converts to javascript in

• jashkenas 16y ago
  CoffeeScript lets you leave off parentheses when they're not necessary to describe what you mean. Your example can also be written as: -> alert 'lambda' (-> alert 'lambda')() # to call it
  • d0m 16y ago
    It's a matter of opinion, but I don't particularly like when you can "omit" things.. and sometime it works and sometime it doesn't. Yes, sometime it makes the code a little clearer, but it can often lead to sneaky bugs and confusion. I mean: map x -> xx seq might be readable .. but: map x -> xx seq seqs is less clear.. while: (map (x -> x*x) (seq seqs)) is more readable.
    • aaronblohowiak 16y ago
      it also increases the friction when you are editing; the question in your mind must be "does this edit require the implicit to be made explicit?" Editor support can help alleviate the drudgery of the change, but I prefer to pay up-front.
    • djacobs 16y ago
      aaronblohowiak, I wonder if "pay up front" is analogous to pre-mature optimization? I'm thinking out loud, mainly because I tend to use the simplest syntax possible when coding in languages that allow for multiple syntaxes (i.e., Ruby). Most of the time, my decisions (at least) work out for me, and I don't have to go back and (say) add parentheses.
    • jashkenas 16y ago
      My two cents on optional parentheses, optional commas, and optional syntax in general are that it's about readability and style. If the statement that you're writing isn't clear without disambiguating the structure, then by all means, use parentheses. But if you're choosing between this: print("Hello"); And this: print "Hello" (Which are equivalent in CoffeeScript) ... I'll take the latter every time.
• gnaritas 16y ago
  That's very similar to the C# syntax () => expression arg => expression arg, arg2 => expression arg => { statement; expression }