use std::str::FromStr;
use std::rc::Rc;
use crate::ast::Form;

grammar;

pub Term: Form = {
    NUM => Form::Int(i32::from_str(<>).unwrap()),
    SYM => Form::Symbol(<>.to_owned()),
	"(" <ListInside?> ")" => <>.unwrap_or(Form::Nil),
	"'" <Term> => Form::Pair(Rc::new(Form::Symbol("quote".to_owned())), Rc::new(Form::Pair(Rc::new(<>), Rc::new(Form::Nil)))),
	"!" <h: Term> <t: Term> => {
        h.append(Rc::new(t)).unwrap()
     },
};
ListInside: Form = {
	<Term> => Form::Pair(Rc::new(<>), Rc::new(Form::Nil)),
	<h: Term> <t: ListInside> => Form::Pair(Rc::new(h), Rc::new(t)),
	<a: Term> "." <d: Term> => Form::Pair(Rc::new(a), Rc::new(d)),
}
match {
    "(",
    ")",
    ".",
    "'",
    "!",
    r"[0-9]+"                                  => NUM,
    r"[a-zA-Z+*/_=?%&|^<>-][\w+*/=_?%&|^<>-]*" => SYM,
    r"(;[^\n]*\n)|\s+"                         => { }
}