1	import Base
2	
3	def Pure(~F:Type -> Type) -> Type:
4	  @-R:Type -> R -> F(R)
5	def Bind(~F:Type -> Type) -> Type:
6	  @-A:Type -> @-B:Type -> F(A) -> (A -> F(B)) -> F(B)
7	def Mapping(~F:Type -> Type) -> Type:
8	  @-A:Type -> @-B:Type -> F(A) -> (A -> B) -> F(B)
9	
10	type Effects<-F:Type -> Type> is Type:
11	  Effects{pure:Pure(~F),bind:Bind(~F),map:Mapping(~F)}
12	
13	def pure(~F:Type -> Type,-R:Type,effects:Effects<F>,value:R) -> F(R):
14	  match effects:
15	    case Effects{pure,_,_}:pure(R,value)
16	def bind(~F:Type -> Type,-A:Type,-B:Type,effects:Effects<F>,action:F(A),next:A -> F(B)) -> F(B):
17	  match effects:
18	    case Effects{_,bind,_}:bind(A,B,action,next)
19	def map(~F:Type -> Type,-A:Type,-B:Type,effects:Effects<F>,action:F(A),next:A -> B) -> F(B):
20	  match effects:
21	    case Effects{_,_,map}:map(A,B,action,next)
22	
23	def Identity(R:Type) -> Type:R
24	def identity_pure(-R:Type,value:R) -> R:value
25	def identity_bind(-A:Type,-B:Type,value:A,next:A -> B) -> B:next(value)
26	def identity_map(-A:Type,-B:Type,value:A,next:A -> B) -> B:next(value)
27	def identity() -> Effects<Identity>:
28	  Effects{identity_pure,identity_bind,identity_map}