Macro polytype::arrow

macro_rules! arrow {
    [$x:expr] => { ... };
    [$x:expr, $($xs:expr),*] => { ... };
    [$x:expr, $($xs:expr,)*] => { ... };
}

Creates an arrow of tp0 → tp1 → ... (convenience for nested arrows).

This is equivalent to:

Type::arrow(tp0,
            Type::arrow(tp1,
                        Type::arrow(tp2,
                        ...
                        )
            )
)

Examples

#[macro_use] extern crate polytype;
use polytype::{Type};

let t = arrow![Type::Variable(0), Type::Variable(1), Type::Variable(2)];
assert_eq!(format!("{}", t), "t0 → t1 → t2");
// Equivalent to:
let t_eq = Type::arrow(Type::Variable(0),
                       Type::arrow(Type::Variable(1),
                                   Type::Variable(2)));
assert_eq!(t, t_eq);