Simplified AST

src/syntax/ast.rs

@@ -12,10 +12,8 @@ pub enum Expr<'a> {
     Map(Vec<(Self, Self)>),
     Symbol(Cow<'a, str>),
     Keyword(Cow<'a, str>),
-    Bool(bool),
     Number(OrderedFloat<f64>),
     String(Cow<'a, str>),
-    Nil,
 }
 
 impl<'a> Display for Expr<'a> {
@@ -31,10 +29,8 @@ impl<'a> Display for Expr<'a> {
             ),
             Self::Symbol(sym) => write!(f, "{sym}"),
             Self::Keyword(kw) => write!(f, ":{kw}"),
-            Self::Bool(b) => write!(f, "{b}"),
             Self::Number(n) => write!(f, "{n}"),
             Self::String(s) => write!(f, "\"{s}\""),
-            Self::Nil => write!(f, "nil"),
         }
     }
 }

src/syntax/parser.rs

@@ -12,9 +12,6 @@ pub fn read(src: &str) -> Result<Vec<Expr>, Vec<Simple<Token<'_>>>> {
 fn parser<'a>() -> impl Parser<Token<'a>, Vec<Expr<'a>>, Error = Simple<Token<'a>>> {
     recursive(|expr| {
         let atom = select! {
-            Token::Symbol("true") => Expr::Bool(true),
-            Token::Symbol("false") => Expr::Bool(false),
-            Token::Symbol("nil") => Expr::Nil,
             Token::Symbol(s) => Expr::Symbol(s.into()),
             Token::Keyword(k) => Expr::Keyword(k.into()),
             Token::String(s) => Expr::String(s.into()),