use std::rc::Rc;
use std::str::FromStr;

use crate::builtin::Builtin;

#[derive(Debug, PartialEq, Clone)]
pub struct PrefixOp {
  pub sigil: Rc<String>,
  pub builtin: Option<Builtin>,
}

impl PrefixOp {
  pub fn sigil(&self) -> &Rc<String> {
    &self.sigil
  }
  pub fn is_prefix(op: &str) -> bool {
    match op {
      "+" => true,
      "-" => true,
      "!" => true,
      _ => false
    }
  }
}

impl FromStr for PrefixOp {
  type Err = ();

  fn from_str(s: &str) -> Result<Self, Self::Err> {
    use Builtin::*;

    let builtin = match s {
      "+" => Ok(Increment),
      "-" => Ok(Negate),
      "!" => Ok(BooleanNot),
      _ => Err(())
    };

    builtin.map(|builtin| PrefixOp { sigil: Rc::new(s.to_string()), builtin: Some(builtin) })
  }
}