Rust JSONRPC Client

Rudimentary support for sending JSONRPC 2.0 requests and receiving responses.

Serde Support

This includes a of macro to enable serialization/deserialization of structures without using stable or nightly. They can be used as follows:

#[macro_use] extern crate jsonrpc;
extern crate serde;

struct MyStruct {
    elem1: bool,
    elem2: String,
    elem3: Vec<usize>
}
serde_struct_impl!(MyStruct, elem1, elem2, elem3 <- "alternate name for elem3");

There is also a variant of this for enums representing structures that might have one of a few possible forms. For example

struct Variant1 {
    success: bool,
    success_message: String
}

struct Variant2 {
    success: bool,
    errors: Vec<String>
}

enum Reply {
    Good(Variant1),
    Bad(Variant2)
}
serde_struct_enum_impl!(Reply, reply_mod,
    Variant1, success, success_message;
    Variant2, success, errors
);

Here reply_mod just needs to be something unique. It is a limitation of the macro system (specifically, I cannot gensym a module) that this has to be there. Suggestions for how to remove this wart on the interface are welcome.

Note that this macro works by returning the first variant for which all fields are present. This means that if one variant is a superset of another, the larger one should be given first to the macro to prevent the smaller from always being matched.

JSONRPC

To send a request which should retrieve the above structure, consider the following example code

#[macro_use] extern crate jsonrpc;
extern crate serde;

struct MyStruct {
    elem1: bool,
    elem2: String,
    elem3: Vec<usize>
}

serde_struct_deserialize!(
    MyStruct,
    MyStructVisitor,
    MyStructField,
    MyStructFieldVisitor,
    elem1 => Elem1,
    elem2 => Elem2,
    elem3 => Elem3
);

fn main() {
    // The two Nones are for user/pass for authentication
    let mut client = jsonrpc::client::Client::new("example.org", None, None);
    let request = client.build_request("getmystruct", vec![]);
    match client.send_request(&request).and_then(|res| res.into_result::<MyStruct>()) {
        Ok(mystruct) => // Ok!
        Err(e) => // Not so much.
    }
}