I am trying to use the rmp_rpc Rust libary to make a server that accepts commands from a client that is written in Python. I am modifying this example to reach my goal.
How can I handle an argument of varying type (integer/string/boolean) into a match statement without getting a "mismatched types; expected i32, found enum 'rmp_rpc::Value'" error? For each method the params types might be different.
fn handle_request(&mut self, method: &str, params: &[Value]) -> Self::RequestFuture {
match method {
"sum" => Methods::sum(params[0], params[1]),
"draw" => Methods::draw(params),
"conc" => Methods::concatenate(params[0], params[1])
}
You need to either perform your type checking here at the call site, or defer type-checking to the callee (the Echo::<whatever> methods).
At the call site:
match method {
"sum" => Echo::sum(params[0].as_u64().expect("expected u64"), params[1].as_u64().expect("expected u64")),
"draw" => Echo::draw(params), // <-- this must continue to be passed as &[Value]
"concatenate => Echo::conc(params[0].as_str().expect("expected str"), params[1].as_str().expect("expected str"))
}
In the callee:
impl Echo {
pub fn sum(v1: Value, v2: Value) -> u64 {
let v1 = v1.as_u64().expect("expected u64");
let v2 = v2.as_u64().expect("expected u64");
v1 + v2
}
}