SML# Document Version 3.7.1
24 Module language declarations and interface

24.4 Module language interface

As defined in Section 16.2, module language interface consists of t provides for structures (provideStr) and for functors (provideFun), whose syntax is given below.

provideStr ::=  structure strid = struct provideStrdecl end
provideStrdecl ::= provideVal
 | provideType
 | provideDatatype
 | provideException
 | provideStr
provideFun ::=  functor provideFunBind
provideFunBind ::= funid (strdesc) = provideStrExp

The following are examples of structure declarations and their interface.

Bool.sml file: structure Bool =
struct
  datatype bool = false | true
  fun not true = false
    | not false = true
  fun toString true = "true"
    | toString false = "false"
end
Bool.smi file: structure Bool =
struct
  datatype bool = false | true
  val not : bool -> bool
  val toString : bool -> string
end