Option (rel.Rel_query.Option)

val v : 'a Rel.Type.t -> 'a option -> 'a option value

v t o is an option of type t.

val none : 'a Rel.Type.t -> 'a option value

none t is v t None.

val some : 'a Rel.Type.t -> 'a value -> 'a option value

some t v is Some v.

val is_none : 'a option value -> bool value

is_none v is true iff v is None.

val is_some : 'a option value -> bool value

is_some v is true ifff v is Some _.

val get : 'a option value -> 'a value

get v is the value of v and an error otherwise.

val has_value : 
  eq:('a value -> 'a value -> bool value) ->
  'a value ->
  'a option value ->
  bool value

val equal : 
  eq:('a value -> 'a value -> bool value) ->
  'a option value ->
  'a option value ->
  bool value