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|
# type foo = ..
# type foo += A | B of int
# val is_a : foo -> bool = <fun>
# type foo
# Characters 13-21:
type foo += A of int (* Error type is not open *)
^^^^^^^^
Error: Cannot extend type definition foo
# type 'a foo = ..
# Characters 1-30:
type ('a, 'b) foo += A of int (* Error: type parameter mismatch *)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error: This extension does not match the definition of type foo
They have different arities.
# module type S = sig type foo type foo += A of float end
# Characters 84-106:
type foo += B of float (* Error foo does not have an extensible type *)
^^^^^^^^^^^^^^^^^^^^^^
Error: Type foo is not extensible
# type foo = ..
# module M :
sig
type foo += A of int | B of string
type foo += C of int | D of float
end
# module type S =
sig
type foo += B of string | C of int
type foo += D of float
type foo += A of int
end
# module M_S : S
# type 'a foo = ..
# type _ foo += A : int -> int foo | B : int foo
# val get_num : 'a foo -> 'a -> 'a option = <fun>
# type 'a foo = .. constraint 'a = [> `Var ]
# type 'a foo += A of 'a
# Characters 11-12:
let a = A 9 (* ERROR: Constraints not met *)
^
Error: This expression has type int but an expression was expected of type
[> `Var ]
# Characters 20-23:
type 'a foo += B : int foo (* ERROR: Constraints not met *)
^^^
Error: This type int should be an instance of type [> `Var ]
# type foo = ..
# module M : sig type foo += A of int end
# val a1 : foo = M.A 10
# module type S = sig type foo += private A of int end
# module M_S : S
# val is_s : foo -> bool = <fun>
# Characters 10-18:
let a2 = M_S.A 20 (* ERROR: Cannot create a value using a private constructor *)
^^^^^^^^
Error: Cannot create values of the private type foo
# type foo = ..
# module M : sig type foo += A1 of int end
# type foo += A2 of int
# type bar = ..
# Characters 18-22:
type bar += A3 = M.A1 (* Error: rebind wrong type *)
^^^^
Error: The constructor M.A1 has type foo but was expected to be of type bar
# module M : sig type foo += private B1 of int end
# type foo += private B2 of int
# Characters 18-22:
type foo += B3 = M.B1 (* Error: rebind private extension *)
^^^^
Error: The constructor M.B1 is private
# Characters 13-24:
type foo += C = Unknown (* Error: unbound extension *)
^^^^^^^^^^^
Error: Unbound constructor Unknown
# module M : sig type foo type foo += A1 of int end
type M.foo += A2 of int
type 'a foo = ..
# type 'a foo1 = 'a foo = ..
# type 'a foo2 = 'a foo = ..
# type 'a foo1 += A of int | B of 'a | C : int foo1
# type 'a foo2 += D of int | E of 'a | F : int foo2
# type +'a foo = ..
# type 'a foo += A of (int -> 'a)
# Characters 1-32:
type 'a foo += B of ('a -> int) (* ERROR: Parameter variances are not satisfied *)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error: In this definition, expected parameter variances are not satisfied.
The 1st type parameter was expected to be covariant,
but it is injective contravariant.
# Characters 1-40:
type _ foo += C : ('a -> int) -> 'a foo (* ERROR: Parameter variances are not satisfied *)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error: In this definition, expected parameter variances are not satisfied.
The 1st type parameter was expected to be covariant,
but it is injective contravariant.
# type 'a bar = ..
# Characters 1-33:
type +'a bar += D of (int -> 'a) (* ERROR: type variances do not match *)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Error: This extension does not match the definition of type bar
Their variances do not agree.
# module M : sig type exn += Foo of int * float | Bar : 'a list -> exn end
# module M :
sig exception Bar : 'a list -> exn exception Foo of int * float end
# exception Foo of int * float
# exception Bar : 'a list -> exn
# module M : sig type exn += Foo of int * float | Bar : 'a list -> exn end
# type foo = ..
# type foo += Foo of int * int option | Bar of int option
# val x : foo * foo = (Foo (3, Some 4), Bar (Some 5))
# type foo += Foo of string
# val y : foo * foo = (<extension>, Bar (Some 5))
# exception Foo of int * int option
# exception Bar of int option
# val x : exn * exn = (Foo (3, Some 4), Bar (Some 5))
# type foo += Foo of string
# val y : exn * exn = (Foo (3, _), Bar (Some 5))
# type foo = ..
# type foo += Foo | Bar of int
# val n1 : string = "Foo"
# val n2 : string = "Bar"
# val t : bool = true
# val f : bool = false
# val is_foo : 'a -> bool = <fun>
type foo += Foo
# val f : bool = false
# Exception: Invalid_argument "Obj.extension_name".
# Exception: Invalid_argument "Obj.extension_id".
#
|
