Type definitions

You can declare your own types using the type keyword.

type CustomStringType = str

NC uses nominal typing rather than structural typing, so if you define a custom type with a different name, that is now a distinct type from the original, and the two cannot be used interchangeably.

fn some_func(str arg) {
  // ...
}

CustomStringType cst = "hello world"
some_func(cst) // error: expected `str`, found `CustomStringType`

Note that you can use the syntax of the underlying type to create the variable. In the example above, cst was initialised using the same "string" syntax as if it were a string, but it cannot be used in the same place that a string can.