Google introduces Dart, a new programming language for web applications

Re:Google introduces Dart, a new programming language for we... by tomp on Monday October 10, 2011 @10:53AM (#3094003)

Actually, I didn't mean to type the whole function, but only the parameters... One would require something like union types, e.g. list_filter has type

  String | `a < SimpleListFilter | (String, `b < FieldListFilter)

Now, this type is certainly encodable in a modern advanced type system (although most statically typed languages utilize type erasure for compilation, so you would need tagged unions (Algebraic Data Types) for this), but I cannot imagine that any language is capable of inferring such a type. Maybe OCaml, but again, we would need polymorphic variants for that.

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Re:Google introduces Dart, a new programming language for we... by Peaker on Monday October 10, 2011 @11:07AM (#3094059)

Instead of (a < SimpleListFilter) you can use a type-class constraint and an existential, or an explicit record of methods. In Haskell, anything you use will basically be inferred, and Haskell can encode that, though you would have to choose different primitives to encode that relationship than subtypes.

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