State for eval

This commit is contained in:
greg 2017-12-03 22:10:19 -08:00
parent ecdcb7ff3d
commit bf42b58ca5

View File

@ -4,10 +4,14 @@ use std::iter::Peekable;
use std::vec::IntoIter;
use std::str::Chars;
pub struct Rukka { }
pub struct EvaluatorState { }
pub struct Rukka {
state: EvaluatorState
}
impl Rukka {
pub fn new() -> Rukka { Rukka { } }
pub fn new() -> Rukka { Rukka { state: EvaluatorState::new() } }
}
impl ProgrammingLanguageInterface for Rukka {
@ -30,7 +34,7 @@ impl ProgrammingLanguageInterface for Rukka {
};
let output_str: String = sexps.into_iter().enumerate().map(|(i, sexp)| {
match eval(sexp) {
match self.state.eval(sexp) {
Ok(result) => format!("{}: {}", i, result.print()),
Err(err) => format!("{} Error: {}", i, err),
}
@ -40,16 +44,20 @@ impl ProgrammingLanguageInterface for Rukka {
}
}
fn eval(expr: Sexp) -> Result<Sexp, String> {
use self::Sexp::*; use self::AtomT::*;
Ok(match expr {
Atom(atom) => match atom {
Symbol(s) => Atom(Symbol(s)),
LangString(s) => Atom(LangString(s)),
Number(s) => Atom(Number(s)),
},
List(items) => unimplemented!(),
})
impl EvaluatorState {
fn new() -> EvaluatorState { EvaluatorState { } }
fn eval(&mut self, expr: Sexp) -> Result<Sexp, String> {
use self::Sexp::*; use self::AtomT::*;
Ok(match expr {
Atom(atom) => match atom {
Symbol(s) => Atom(Symbol(s)),
LangString(s) => Atom(LangString(s)),
Number(s) => Atom(Number(s)),
},
List(items) => unimplemented!(),
})
}
}
fn read(input: &str) -> Result<Vec<Sexp>, String> {