RIE is REPL-like interactive code editor.
# cargo install rie
# rie
>> :2 * 2
= 4
>> let x = 2
=
>> :x * 2
= 4
>> let f = |x : i32| x * x
=
>> :f(4)
= 16
>> %
0 fn main() {
1 let x = 2;
2 let f = |x : i32| x * x;
3 }
>> %d 2
0 fn main() {
1 let x = 2;
2 }
>> {{
>>> fn foo() {
>>> println!("Hello world");
>>> }
>>> }}
=
>> :foo()
= Hello world
()