Make.GenClient
SourceThis module generates Client modules from RPC declarations.
The implementation
of the module as a whole is unused. However, the namespace comes from the interface description, and hence calling implement
is important.
The result of declaring a function of type 'a (where for example 'a might be (int -> string -> (bool, err) result)
), is a function that takes an rpc function, which might send the RPC across the network, and returns a function of type 'a, in this case (int -> string -> (bool, err) result)
.
Our functions return a Result.t
type, which contains the result of the Rpc, which might be an error message indicating a problem happening on the remote end.
include RPC
with type implementation = client_implementation
and type 'a res = T.rpcfn -> 'a
and type ('a, 'b) comp = ('a, 'b) T.resultb
The implementation is dependent on the module, and represents the 'result' of the entire module. For example, in the Server module, the `implementation` is the server function, with type
Rpc.call -> Rpc.response.
For the Client module, the individual declarations are used to perform the RPCs, and the 'implementation' type is simply unit.
To actually construct the implementation, an interface description must be provided
'a res is the result type of declaring a function. For example, the Client module, given an (int -> int -> int) fn, will return a function of type 'a - in this case, (int -> int -> int)
This is for inserting a type in between the function application and its result. For example, this could be an Lwt.t, meaning that the result of a function application is a thread
The GADT specifying the type of the RPC
This infix operator is for constructing function types
Require a unit argument in OCaml without sending a parameter. Useful for methods that take no arguments.
This defines the return type of an RPC
declare name description typ
is how an RPC is declared to the module implementing the functionality. The return type is dependent upon the module being used
This is irreversible, once used the client will fail in case of Rpc failure (M.fail
) instead of returning the error (M.return (Error ...)
).