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True and False primitives

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This commit is contained in:
greg 2017-12-07 19:51:34 -08:00
parent adc7be30a9
commit ad58fc1ad1
1 changed files with 8 additions and 0 deletions
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8
src/rukka_lang/mod.rs
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@ -53,6 +53,8 @@ impl EvaluatorState {
SymbolAtom(sym) => unimplemented!(), SymbolAtom(sym) => unimplemented!(),
expr @ StringAtom(_) => expr, expr @ StringAtom(_) => expr,
expr @ NumberAtom(_) => expr, expr @ NumberAtom(_) => expr,
True => True,
False => False,
Cons(box operator, box operands) => { Cons(box operator, box operands) => {
match operator { match operator {
SymbolAtom(ref sym) => match &sym[..] { SymbolAtom(ref sym) => match &sym[..] {
@ -116,6 +118,8 @@ enum Sexp {
SymbolAtom(String), SymbolAtom(String),
StringAtom(String), StringAtom(String),
NumberAtom(u64), NumberAtom(u64),
True,
False,
Cons(Box<Sexp>, Box<Sexp>), Cons(Box<Sexp>, Box<Sexp>),
Nil Nil
} }
@ -124,6 +128,8 @@ impl Sexp {
fn print(&self) -> String { fn print(&self) -> String {
use self::Sexp::*; use self::Sexp::*;
match self { match self {
&True => format!("#t"),
&False => format!("#f"),
&SymbolAtom(ref sym) => format!("{}", sym), &SymbolAtom(ref sym) => format!("{}", sym),
&StringAtom(ref s) => format!("\"{}\"", s), &StringAtom(ref s) => format!("\"{}\"", s),
&NumberAtom(ref n) => format!("{}", n), &NumberAtom(ref n) => format!("{}", n),
@ -179,6 +185,8 @@ fn parse(tokens: &mut Peekable<IntoIter<Token>>) -> Result<Sexp, String> {
use self::Token::*; use self::Token::*;
use self::Sexp::*; use self::Sexp::*;
match tokens.next() { match tokens.next() {
Some(Word(ref s)) if s == "#f" => Ok(False),
Some(Word(ref s)) if s == "#t" => Ok(True),
Some(Word(s)) => Ok(SymbolAtom(s)), Some(Word(s)) => Ok(SymbolAtom(s)),
Some(StringLiteral(s)) => Ok(StringAtom(s)), Some(StringLiteral(s)) => Ok(StringAtom(s)),
Some(LParen) => parse_sexp(tokens), Some(LParen) => parse_sexp(tokens),