• smart function @ binding (select -> or => automatically)
• enhanced blocks
  • array blocks
  • function invocation blocks
  • "blocks instead of brackets"
• eliminate the need for token matching ([], {}, "", etc)
• with
• improved multi-line binary operator semantics (./+/- etc)
• improved pattern assignment
• Tail catch
  • result = doSomethingRisky() catch “it failed”
• Enhanced class System
  • real class inheritance
    • CoffeeScript copies all class properties from the base class and definition time
      • updates to class properties after definition time are not propagated to child classes
      • @classGetters & @classSetters are not inherited at all
    • requires object instantition to look like Ruby: MyClass.new a, b, c
  • more consistent access to super and prototypes
    • @:: is a confusing concept in CoffeeScript. We can do better.
  • dynamic class creation
    • create classes with names created at runtime
  • default extends class
    • all classes without an explicit extend statement extend the same base class, which in turn extends Object
• streamlined switch statement
• new string literals
  • I’d like to add something like :foo == “foo”, but I want to look at ES6 (EcmaScript6) 'symbols' first
  • I’d like to add some syntax like the Ruby language's: %w{a long word list becomes array of strings}
• efficiency & performance
  • use small runtime to reduce overall code-size and increase functionality
  • reduced overhead with @-binding
  • faster (a...) ->
  • 'real class inheritance' will be faster
• improved literate programming
• operator overloading if it can-be done efficiently
• object key interpolation: "hi#{foo}": 123, ('this' + a): 123
• smart '@' binding
• postCreate for classes
• map, each and for loops
• streamlined "require"
• make ranges more like ruby ranges
  • can be used anywhere
    • j...k
    • {begin: j, end: k, excludeEnd: true}
  • don't need brackets []
    • for i in j...k
• I do like the idea of fixing the "a + b" vs “a +b” ambiguity. Plus as a unary operator is kinda silly. Even minus as a unitary operator may be more pain than it’s worth. When you ever need it (rarely), “0 - foo” is only one more symbol.
• CoffeeScript compiler errors suggests language features
  • I run into this a lot in CoffeeScript. Something I think makes perfect logical sense is illegal because, in my opinion, the compile is incomplete.
  • In general, whenever there is a compiler error for something which is logically consistent with the rest of the language (and parsing rules), that suggests an opportunity for a more expressive language.

related projects

• Caffeine (git)
  • Another project forked from CoffeeScript. It hasn't been updated since 2013.