Static Typing Model

Felix uses an ML style static type system with C++ template style compile time polymorphism.

Anonymous Types
Name
 Sample Type annotation
 Sample Value
 Comments
Tuple int * long * double
 1,2L,3.0
 Categorical product
Unit
 1
 ()
 Degenerate product
Variant
 int + long
 (case 1 of int+long) 2
 Categorical sum
Void
 0
Degenerate sum
Array
 int ^ 3
 1,2,3
 Special tuple
Function
 int -> int
 fun (x:int) => x * x
 May not have side effects
Procedure
 int->void
 proc (x:int){ print x; }
 Evaluated for side effects

Generative Types
Name
 Sample Type Definition Sample Value
 Comments
Struct struct X { x:int; y:long; } X(1,2L) Categorical product
Union union U = | Some of int | None; (case 1 of int+long) 2
 Categorical sum
Enum
 enum E {False; True};
 False
 Special union