Macro sewup_derive::ewasm_fn_sig

ewasm_fn_sig!() { /* proc-macro */ }

helps you get you function signature

1. provide function name to get function signature from the same namespace, which function should be decorated with #[ewasm_fn], for example, ewasm_fn_sig!(contract_handler)

#[ewasm_fn]
fn decorated_handler(a: i32, b: String) -> Result<()> {
    Ok(())
}

#[ewasm_main]
fn main() -> Result<()> {
    let contract = Contract::new()?;
    match contract.get_function_selector()? {
        ewasm_fn_sig!(decorated_handler) => ewasm_input_from!(contract move decorated_handler)?,
        _ => return Err(Error::UnknownHandle.into()),
    };
    Ok(())
}

2. provide a function name with input parameters then the macro will calculate the correct functional signature for you. ex: ewasm_fn_sig!(undecorated_handler( a: i32, b: String ))

// some_crate.rs
pub fn decorated_handler(a: i32, b: String) -> Result<()> {
    Ok(())
}

use some_crate::decorated_handler;

#[ewasm_main]
fn main() -> Result<()> {
    let contract = Contract::new()?;
    match contract.get_function_selector()? {
        ewasm_fn_sig!(undecorated_handler(a: i32, b: String))
            => ewasm_input_from!(contract move undecorated_handler)?,
        _ => return Err(Error::UnknownHandle.into()),
    };
    Ok(())
}