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Type simplification

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This commit is contained in:
greg 2017-12-03 22:20:43 -08:00
parent bf42b58ca5
commit 559eaf54de
1 changed files with 17 additions and 25 deletions
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42
src/rukka_lang/mod.rs
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@ -48,13 +48,11 @@ impl ProgrammingLanguageInterface for Rukka {
impl EvaluatorState {
fn new() -> EvaluatorState { EvaluatorState { } }
fn eval(&mut self, expr: Sexp) -> Result<Sexp, String> {
use self::Sexp::*; use self::AtomT::*;
use self::Sexp::*;
Ok(match expr {
Atom(atom) => match atom {
Symbol(s) => Atom(Symbol(s)),
LangString(s) => Atom(LangString(s)),
Number(s) => Atom(Number(s)),
},
SymbolAtom(sym) => unimplemented!(),
expr @ StringAtom(_) => expr,
expr @ NumberAtom(_) => expr,
List(items) => unimplemented!(),
})
}
@ -82,31 +80,24 @@ enum Token {
#[derive(Debug)]
enum Sexp {
Atom(AtomT),
SymbolAtom(String),
StringAtom(String),
NumberAtom(u64),
List(Vec<Sexp>),
}
impl Sexp {
fn print(&self) -> String {
use self::Sexp::*; use self::AtomT::*;
use self::Sexp::*;
match self {
&Atom(ref atom) => match atom {
&Symbol(ref s) => format!("{}", s),
&LangString(ref s) => format!("\"{}\"", s),
&Number(ref n) => format!("{}", n),
},
_ => format!("<unprintable>")
&SymbolAtom(ref sym) => format!("{}", sym),
&StringAtom(ref s) => format!("\"{}\"", s),
&NumberAtom(ref n) => format!("{}", n),
&List(ref sexprs) => format!("<unprintable>"),
}
}
}
#[derive(Debug)]
enum AtomT {
Symbol(String),
LangString(String),
Number(u64),
}
fn tokenize(input: &mut Peekable<Chars>) -> Vec<Token> {
use self::Token::*;
let mut tokens = Vec::new();
@ -154,16 +145,17 @@ fn tokenize(input: &mut Peekable<Chars>) -> Vec<Token> {
fn parse(tokens: &mut Peekable<IntoIter<Token>>) -> Result<Sexp, String> {
use self::Token::*;
use self::Sexp::*;
match tokens.next() {
Some(Word(s)) => Ok(Sexp::Atom(AtomT::Symbol(s))),
Some(StringLiteral(s)) => Ok(Sexp::Atom(AtomT::LangString(s))),
Some(Word(s)) => Ok(SymbolAtom(s)),
Some(StringLiteral(s)) => Ok(StringAtom(s)),
Some(LParen) => parse_sexp(tokens),
Some(RParen) => Err(format!("Unexpected ')'")),
Some(Quote) => {
let quoted = parse(tokens)?;
Ok(Sexp::List(vec![Sexp::Atom(AtomT::Symbol(format!("quote"))), quoted]))
Ok(List(vec![SymbolAtom(format!("quote")), quoted]))
},
Some(NumLiteral(n)) => Ok(Sexp::Atom(AtomT::Number(n))),
Some(NumLiteral(n)) => Ok(NumberAtom(n)),
None => Err(format!("Unexpected end of input")),
}
}