add serialization of values

example/repl.rs

@@ -1,4 +1,4 @@
-use std::io::stdin;
+use std::io::{stdin, stdout, Write};
 
 use microlang::Context;
 
@@ -6,9 +6,14 @@ pub fn main() {
 	unsafe { backtrace_on_stack_overflow::enable() };
 	let mut context = Context::empty();
 	loop {
+		print!("> ");
+		stdout().flush().ok();
 		let mut line = String::new();
 		stdin().read_line(&mut line).unwrap();
 		let res = context.eval(line);
-		dbg!(res).ok();
+		match res {
+			Ok((_, value)) => println!("{}", value.serialize()),
+			Err(e) => println!("Error : {e:?}"),
+		}
 	}
 }