Module Imandra_prelude.Option

Option module

The option type type 'a option = None | Some of 'a is useful for representing partial functions and optional values.

type 'a t = 'a option
val map : ( 'a -> 'b ) -> 'a option -> 'b option

Map over the option.

  • map f None = None
  • map f (Some x) = Some (f x)
val map_or : default:'a -> ( 'b -> 'a ) -> 'b option -> 'a
val is_some : 'a option -> bool

Returns true iff the argument is of the form Some x

val is_none : 'a option -> bool

Returns true iff the argument is None

val return : 'a -> 'a option

Wrap a value into an option. return x = Some x

val (>|=) : 'a option -> ( 'a -> 'b ) -> 'b option

Infix alias to map

val flat_map : ( 'a -> 'b option ) -> 'a option -> 'b option

Monadic operator, useful for chaining multiple optional computations

val (>>=) : 'a option -> ( 'a -> 'b option ) -> 'b option

Infix monadic operator, useful for chaining multiple optional computations together. It holds that (return x >>= f) = f x

val or_ : else_:'a option -> 'a option -> 'a option

Choice of a value

  • or_ ~else_:x None = x
  • or_ ~else_:x (Some y) = Some y
val (<+>) : 'a option -> 'a option -> 'a option
val exists : ( 'a -> bool ) -> 'a option -> bool
val for_all : ( 'a -> bool ) -> 'a option -> bool
val get_or : default:'a -> 'a option -> 'a
val fold : ( 'a -> 'b -> 'a ) -> 'a -> 'b option -> 'a
val (<$>) : ( 'a -> 'b ) -> 'a option -> 'b option

f <$> x = map f x

val monoid_product : 'a option -> 'b option -> ('a * 'b) option
val let+ : 'a option -> ( 'a -> 'b ) -> 'b option
val and+ : 'a option -> 'b option -> ('a * 'b) option
val let* : 'a option -> ( 'a -> 'b option ) -> 'b option
val and* : 'a option -> 'b option -> ('a * 'b) option