use std::io;
use std::io::Write;

mod cexpr;
mod rewrite;
mod sexpr;

pub use cexpr::{CExpr, CNumber};
pub use rewrite::Rule;
pub use sexpr::{sexpr_parse_file, SExpr};

pub type Result<T, E = String> = std::result::Result<T, E>;

pub fn repl(_verbose: bool) {
    let stdin = io::stdin();
    let mut stdout = io::stdout();

    loop {
        let raw_input = &mut String::new();
        stdout.write(b"\ncasual> ").unwrap();
        stdout.flush().unwrap();
        stdin.read_line(raw_input).unwrap();
        let raw_input = raw_input; // mutable to immutable reference
        if raw_input.len() == 0 {
            // end-of-line, aka Ctrl-D. Blank line will still have newline char
            stdout.write(b"\nCiao!\n").unwrap();
            return;
        }
        let expr = match CExpr::from_str(&raw_input) {
            Ok(expr) => expr,
            Err(e) => {
                println!("error: {}", e);
                continue;
            }
        };
        println!("{}", expr);
    }
}