From 92d641fca0b644b8598d8b1e75fb42de898852e4 Mon Sep 17 00:00:00 2001 From: greg Date: Sun, 10 Dec 2017 03:35:51 -0800 Subject: [PATCH] Make var methods better --- src/rukka_lang/mod.rs | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) diff --git a/src/rukka_lang/mod.rs b/src/rukka_lang/mod.rs index 7f671a0..1e0b683 100644 --- a/src/rukka_lang/mod.rs +++ b/src/rukka_lang/mod.rs @@ -9,6 +9,25 @@ pub struct EvaluatorState { vars: HashMap } +impl EvaluatorState { + fn new() -> EvaluatorState { + EvaluatorState { + vars: HashMap::new(), + } + } + fn set_var(&mut self, var: String, value: Sexp) { + self.vars.insert(var, value); + } + fn get_var(&self, var: &str) -> Option<&Sexp> { + self.vars.get(var) + } + fn push_env(&mut self) { + } + fn pop_env(&mut self) { + + } +} + pub struct Rukka { state: EvaluatorState } @@ -48,16 +67,11 @@ impl ProgrammingLanguageInterface for Rukka { } impl EvaluatorState { - fn new() -> EvaluatorState { - EvaluatorState { - vars: HashMap::new(), - } - } fn eval(&mut self, expr: Sexp) -> Result { use self::Sexp::*; Ok(match expr { SymbolAtom(ref sym) => { - match self.vars.get(sym) { + match self.get_var(sym) { Some(ref sexp) => { let q: &Sexp = sexp; //WTF? if I delete this line, the copy doesn't work?? q.clone() //TODO make this not involve a clone @@ -105,7 +119,7 @@ impl EvaluatorState { "define" => match operands { Cons(box SymbolAtom(sym), box Cons(box expr, box Nil)) => { let evaluated = self.eval(expr)?; - self.vars.insert(sym, evaluated); + self.set_var(sym, evaluated); Nil }, _ => return Err(format!("Bad assignment")),