handball/src/main.rs

#![feature(array_windows)]
#![feature(assert_matches)]
#![feature(box_patterns)]
#![feature(crate_visibility_modifier)]
#![feature(let_else)]

use std::io;

use rustyline::validate::{
    MatchingBracketValidator, ValidationContext, ValidationResult, Validator,
};
use rustyline::Editor;
use rustyline_derive::{Completer, Helper, Highlighter, Hinter};

mod ast;
mod eval;
#[allow(clippy::all)]
mod grammar;
mod prims;
#[cfg(test)]
mod tests;
mod value;

fn main() {
    let args = std::env::args().collect::<Vec<_>>();
    match &args[..] {
        [_] => repl(),
        [_, file] => run_file(file).unwrap(),
        _ => panic!("To many args `{:?}`", args),
    }
}

fn run_file(file: &str) -> io::Result<()> {
    let src = std::fs::read_to_string(file)?;
    let tree = grammar::FileParser::new().parse(&src).unwrap();
    let mut env = eval::default_env();
    for i in tree {
        eval::eval(&i, &mut env).unwrap();
    }
    Ok(())
}

fn repl() {
    let mut rl = Editor::new();
    rl.set_helper(Some(InputValidator {
        brackets: MatchingBracketValidator::new(),
    }));

    let mut env = eval::default_env();

    while let Ok(line) = rl.readline("> ") {
        rl.add_history_entry(&line);

        let tree = grammar::TreeParser::new().parse(&line).unwrap();
        // dbg!(&tree);
        println!("< {:?}", eval::eval(&tree, &mut env))
    }
}

#[derive(Completer, Helper, Highlighter, Hinter)]
struct InputValidator {
    brackets: MatchingBracketValidator,
}

impl Validator for InputValidator {
    fn validate(&self, ctx: &mut ValidationContext) -> rustyline::Result<ValidationResult> {
        self.brackets.validate(ctx)
    }
}