cl-ast: Add float support

- Smuggle floats as integers to maintain `eq`
- This is bad, but not terrible for spec-compliant floats. Might have issues with NaN.

cl_parser: Smuggle floats

cl_interpret: unpack smuggled floats in float literal node

compiler/cl-ast/src/ast.rs

@@ -36,6 +36,7 @@ pub enum Literal {
     Bool(bool),
     Char(char),
     Int(u128),
+    Float(u64),
     String(String),
 }
 

compiler/cl-ast/src/ast_impl.rs

@@ -50,6 +50,7 @@ mod display {
                 Literal::Bool(v) => v.fmt(f),
                 Literal::Char(v) => write!(f, "'{}'", v.escape_debug()),
                 Literal::Int(v) => v.fmt(f),
+                Literal::Float(v) => f64::from_bits(*v).fmt(f),
                 Literal::String(v) => write!(f, "\"{}\"", v.escape_debug()),
             }
         }

compiler/cl-ast/src/ast_visitor/fold.rs

@@ -37,6 +37,9 @@ pub trait Fold {
     fn fold_int(&mut self, i: u128) -> u128 {
         i
     }
+    fn fold_smuggled_float(&mut self, f: u64) -> u64 {
+        f
+    }
     fn fold_string(&mut self, s: String) -> String {
         s
     }
@@ -384,6 +387,7 @@ pub fn or_fold_literal<F: Fold + ?Sized>(folder: &mut F, lit: Literal) -> Litera
         Literal::Bool(b) => Literal::Bool(folder.fold_bool(b)),
         Literal::Char(c) => Literal::Char(folder.fold_char(c)),
         Literal::Int(i) => Literal::Int(folder.fold_int(i)),
+        Literal::Float(f) => Literal::Float(folder.fold_smuggled_float(f)),
         Literal::String(s) => Literal::String(folder.fold_string(s)),
     }
 }

compiler/cl-ast/src/ast_visitor/visit.rs

@@ -23,6 +23,7 @@ pub trait Visit<'a>: Sized {
     fn visit_bool(&mut self, _b: &'a bool) {}
     fn visit_char(&mut self, _c: &'a char) {}
     fn visit_int(&mut self, _i: &'a u128) {}
+    fn visit_smuggled_float(&mut self, _f: &'a u64) {}
     fn visit_string(&mut self, _s: &'a str) {}
     fn visit_file(&mut self, f: &'a File) {
         let File { items } = f;
@@ -339,6 +340,7 @@ pub fn or_visit_literal<'a, V: Visit<'a>>(visitor: &mut V, l: &'a Literal) {
         Literal::Bool(b) => visitor.visit_bool(b),
         Literal::Char(c) => visitor.visit_char(c),
         Literal::Int(i) => visitor.visit_int(i),
+        Literal::Float(f) => visitor.visit_smuggled_float(f),
         Literal::String(s) => visitor.visit_string(s),
     }
 }

compiler/cl-interpret/src/interpret.rs

@@ -453,7 +453,7 @@ impl Interpret for Literal {
             Literal::String(value) => ConValue::from(value.as_str()),
             Literal::Char(value) => ConValue::Char(*value),
             Literal::Bool(value) => ConValue::Bool(*value),
-            // Literal::Float(value) => todo!("Float values in interpreter: {value:?}"),
+            Literal::Float(value) => ConValue::Float(f64::from_bits(*value)),
             Literal::Int(value) => ConValue::Int(*value as _),
         })
     }

compiler/cl-parser/src/parser.rs

@@ -245,7 +245,7 @@ impl Parse<'_> for Literal {
             TokenData::String(v) => Literal::String(v),
             TokenData::Character(v) => Literal::Char(v),
             TokenData::Integer(v) => Literal::Int(v),
-            TokenData::Float(v) => todo!("Literal::Float({v})"),
+            TokenData::Float(v) => Literal::Float(v.to_bits()),
             _ => panic!("Expected token data for {ty:?}"),
         })
     }