Type aliases

[cie]

Hi, Do you plan to have type aliases? The other day I wrote this signature:

fun seq(ps : Array(Function(Array(t), Result(Tuple(String, Array(t)), Tuple(String, Array(t)))))) {

Instead I'd like to write something like

type ParseErr(t) = Tuple(String, Array(t))
type ParseOk(t) = Tuple(String, Array(t))
type Production(t) = Function(Array(t), Result(ParseErr(t), ParseOk(t)))

fun seq(ps : Array(Production(t))) {

or without type parameters and with module scoping

type Grammar.ParseErr = Tuple(String, Array(Token))
type Grammar.ParseOk = Tuple(String, Array(Token))
type Grammar.Production = Function(Array(Token), Result(Grammar.ParseErr, Grammar.ParseOk))

module Grammar {
  fun seq(ps : Array(Grammar.Production)) {

[gdotdesign]

In my opinion type aliases adds some complexity when reading code (that's why I didn't implemented it yet) but you're not the first person asking for it, so it will probably happen at some point.

The keyword probably will be alias instead of type.

[cie]

Thanks! It's not urgent for me.

It can be BTW worked around with a single-valued enum:

enum Production(t) {
  Of(Function(Array(t), Result(Tuple(String, Array(t)), Tuple(String, Array(t)))))
}
fun seq(ps: Array(Production(t)))
seq(Production::Of(number))

but that hurts code cleanness on the call site.