use crate::{symbol::Symbol, val::Val};

#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub enum Ident {
    /// `x`
    Local(Symbol),
    /// `^x`
    Return(Symbol),
}

#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub enum BinOp {
    Add,
    Sub,
    Mul,
    Div,
    Mod,
    Pow,
    Eq,
    Lt,
    Le,
}

// TODO: great display repr for this for testing (yes it's allowed)
#[derive(Debug, Clone)]
pub enum Ast {
    /// `x`, `^x`
    Var(Ident),
    /// `x := y; #=> y`
    Set(Ident, Box<Ast>),
    /// `fn ([a b] [c d]) ( ... )`
    Fn {
        inputs: Vec<Symbol>,
        outputs: Vec<Symbol>,
        body: Vec<Ast>,
    },
    /// `{^x; ^y := z}`
    Map(Vec<Ast>),
    /// `f x`
    App(Box<Ast>, Box<Ast>),
    /// `x + y` (only builtins, sorry)
    BinOp(Box<Ast>, BinOp, Box<Ast>),
    /// `3`
    Num(f64),
    /// `(println bla; 3) #=> 3`
    Block(Vec<Ast>),
}