Functions and function arguments

orpc declaration	ONC RPC equivalent
val ping : unit -> unit	void ping(void) = 0
val add : int -> int -> int	int add(int,int,int) = 0
val add : (int * int) -> int	int add(int,int,int) = 0
val add : ?m:int -> int -> int	int add(int *, int) = 0
val add : ~m:int -> ~n:int -> int	int add(int, int) = 0

Remote procedures are declared as OCaml functions. It’s not necessary (or possible) to give an RPC function number; functions are numbered from 0 in the order they appear in the file.

Multiple arguments may be given curried or tupled; either way you get the same ONC RPC equivalent. Labelled and optional arguments may also be used, although of course the labels do not show up in the ONC RPC equivalent.

Any built-in types or types that have been previously been declared in the input file may be given as function argument types, subject to the following restrictions (in all cases because there is no sensible way to marshal values):

• Higher-order functions are not supported
• exn is not supported (but see Exceptions)
• Polymorphic types must be instantiated; in particular polymorphic variants must be closed

It is also possible to use types declared in another module; see Type-conv support.