for longer discussions on some of these utilities.
(* Operator precedence table *)
infix 8 * / div mod (* +1 from Basis Library *)
infix 7 + - ^ (* +1 from Basis Library *)
infixr 6 :: @ (* +1 from Basis Library *)
infix 5 = <> > >= < <= (* +1 from Basis Library *)
infix 4 <\ \>
infixr 4 </ />
infix 3 o
infix 2 >|
infixr 2 |<
infix 1 := (* -2 from Basis Library *)
infix 0 before &
(* Some basic combinators *)
fun const x _ = x
fun cross (f, g) (x, y) = (f x, g y)
fun curry f x y = f (x, y)
fun fail e _ = raise e
fun id x = x
(* Product type *)
datatype ('a, 'b) product = & of 'a * 'b
(* Sum type *)
datatype ('a, 'b) sum = INL of 'a | INR of 'b
(* Some type shorthands *)
type 'a uop = 'a -> 'a
type 'a fix = 'a uop -> 'a
type 'a thunk = unit -> 'a
type 'a effect = 'a -> unit
type ('a, 'b) emb = ('a -> 'b) * ('b -> 'a)
(* Infixing, sectioning, and application operators *)
fun x <\ f = fn y => f (x, y)
fun f \> y = f y
fun f /> y = fn x => f (x, y)
fun x </ f = f x
(* Piping operators *)
val op>| = op</
val op|< = op\>