Merge pull request 'Basic floating point support (WIP)' (#18) from floats into main

Reviewed-on: #18

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) => write!(f, "{:?}", f64::from_bits(*v)),
                 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/builtin.rs

@@ -223,6 +223,7 @@ builtins! {
         Ok(match tail {
             ConValue::Empty => ConValue::Empty,
             ConValue::Int(v) => ConValue::Int(v.wrapping_neg()),
+            ConValue::Float(v) => ConValue::Float(-v),
             _ => Err(Error::TypeError)?,
         })
     }

compiler/cl-interpret/src/convalue.rs

@@ -20,6 +20,8 @@ pub enum ConValue {
     Empty,
     /// An integer
     Int(Integer),
+    /// A floating point number
+    Float(f64),
     /// A boolean
     Bool(bool),
     /// A unicode character
@@ -124,6 +126,7 @@ macro cmp ($($fn:ident: $empty:literal, $op:tt);*$(;)?) {$(
         match (self, other) {
             (Self::Empty, Self::Empty) => Ok(Self::Bool($empty)),
             (Self::Int(a), Self::Int(b)) => Ok(Self::Bool(a $op b)),
+            (Self::Float(a), Self::Float(b)) => Ok(Self::Bool(a $op b)),
             (Self::Bool(a), Self::Bool(b)) => Ok(Self::Bool(a $op b)),
             (Self::Char(a), Self::Char(b)) => Ok(Self::Bool(a $op b)),
             (Self::String(a), Self::String(b)) => Ok(Self::Bool(&**a $op &**b)),
@@ -150,6 +153,7 @@ impl From<&Sym> for ConValue {
 }
 from! {
     Integer => ConValue::Int,
+    f64 => ConValue::Float,
     bool => ConValue::Bool,
     char => ConValue::Char,
     Sym => ConValue::String,
@@ -189,7 +193,8 @@ ops! {
     Add: add = [
         (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
         (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_add(b)),
-        (ConValue::String(a), ConValue::String(b)) => (a.to_string() + &b.to_string()).into(),
+        (ConValue::Float(a), ConValue::Float(b)) => ConValue::Float(a + b),
+        (ConValue::String(a), ConValue::String(b)) => (a.to_string() + &*b).into(),
         (ConValue::String(s), ConValue::Char(c)) => { let mut s = s.to_string(); s.push(c); s.into() }
         (ConValue::Char(a), ConValue::Char(b)) => {
             ConValue::String([a, b].into_iter().collect::<String>().into())
@@ -219,18 +224,21 @@ ops! {
         (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.checked_div(b).unwrap_or_else(|| {
             eprintln!("Warning: Divide by zero in {a} / {b}"); a
         })),
+        (ConValue::Float(a), ConValue::Float(b)) => ConValue::Float(a / b),
         _ => Err(Error::TypeError)?
     ]
     Mul: mul = [
         (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
         (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_mul(b)),
+        (ConValue::Float(a), ConValue::Float(b)) => ConValue::Float(a * b),
         _ => Err(Error::TypeError)?
     ]
     Rem: rem = [
         (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
         (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.checked_rem(b).unwrap_or_else(|| {
-            eprintln!("Warning: Divide by zero in {a} % {b}"); a
+            println!("Warning: Divide by zero in {a} % {b}"); a
         })),
+        (ConValue::Float(a), ConValue::Float(b)) => ConValue::Float(a % b),
         _ => Err(Error::TypeError)?
     ]
     Shl: shl = [
@@ -246,6 +254,7 @@ ops! {
     Sub: sub = [
         (ConValue::Empty, ConValue::Empty) => ConValue::Empty,
         (ConValue::Int(a), ConValue::Int(b)) => ConValue::Int(a.wrapping_sub(b)),
+        (ConValue::Float(a), ConValue::Float(b)) => ConValue::Float(a - b),
         _ => Err(Error::TypeError)?
     ]
 }
@@ -254,6 +263,7 @@ impl std::fmt::Display for ConValue {
         match self {
             ConValue::Empty => "Empty".fmt(f),
             ConValue::Int(v) => v.fmt(f),
+            ConValue::Float(v) => v.fmt(f),
             ConValue::Bool(v) => v.fmt(f),
             ConValue::Char(v) => v.fmt(f),
             ConValue::String(v) => v.fmt(f),

compiler/cl-interpret/src/interpret.rs

@@ -358,6 +358,9 @@ fn cast(value: ConValue, ty: Sym) -> IResult<ConValue> {
         ConValue::Bool(b) => b as _,
         ConValue::Char(c) => c as _,
         ConValue::Ref(v) => return cast((*v).clone(), ty),
+        // TODO: This, better
+        ConValue::Float(_) if ty.starts_with('f') => return Ok(value),
+        ConValue::Float(f) => f as _,
         _ => Err(Error::TypeError)?,
     };
     Ok(match &*ty {
@@ -369,6 +372,8 @@ fn cast(value: ConValue, ty: Sym) -> IResult<ConValue> {
         "i32" => ConValue::Int(value as i32 as _),
         "u64" => ConValue::Int(value),
         "i64" => ConValue::Int(value),
+        "f32" => ConValue::Float(value as f32 as _),
+        "f64" => ConValue::Float(value as f64 as _),
         "char" => ConValue::Char(char::from_u32(value as _).unwrap_or('\u{fffd}')),
         "bool" => ConValue::Bool(value < 0),
         _ => Err(Error::NotDefined(ty))?,
@@ -448,7 +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-lexer/src/lib.rs

@@ -378,16 +378,32 @@ impl<'t> Lexer<'t> {
             Ok('d') => self.consume()?.digits::<10>(),
             Ok('o') => self.consume()?.digits::<8>(),
             Ok('b') => self.consume()?.digits::<2>(),
-            Ok('0'..='9') => self.digits::<10>(),
+            Ok('0'..='9' | '.') => self.digits::<10>(),
             _ => self.produce(Kind::Literal, 0),
         }
     }
     fn digits<const B: u32>(&mut self) -> LResult<Token> {
-        let mut value = self.digit::<B>()? as u128;
+        let mut value = 0;
         while let Ok(true) = self.peek().as_ref().map(char::is_ascii_alphanumeric) {
             value = value * B as u128 + self.digit::<B>()? as u128;
         }
-        self.produce(Kind::Literal, value)
+        // TODO: find a better way to handle floats in the tokenizer
+        match self.peek() {
+            Ok('.') => {
+                // FIXME: hack: 0.. is not [0.0, '.']
+                if let Ok('.') = self.clone().consume()?.next() {
+                    return self.produce(Kind::Literal, value);
+                }
+                let mut float = format!("{value}.");
+                self.consume()?;
+                while let Ok(true) = self.peek().as_ref().map(char::is_ascii_digit) {
+                    float.push(self.iter.next().unwrap_or_default());
+                }
+                let float = f64::from_str(&float).expect("must be parsable as float");
+                self.produce(Kind::Literal, float)
+            }
+            _ => self.produce(Kind::Literal, value),
+        }
     }
     fn digit<const B: u32>(&mut self) -> LResult<u32> {
         let digit = self.peek()?;

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:?}"),
         })
     }

compiler/cl-parser/src/parser/prec.rs

@@ -247,9 +247,9 @@ fn structor_body(p: &mut Parser, to: Path) -> PResult<Structor> {
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub enum Precedence {
     Assign,
+    Logic,
     Compare,
     Range,
-    Logic,
     Bitwise,
     Shift,
     Factor,

repline/examples/repl_float.rs

@@ -0,0 +1,17 @@
+//! Demonstrates the use of [read_and()]:
+//! 
+//! The provided closure:
+//! 1. Takes a line of input (a [String])
+//! 2. Performs some calculation (using [FromStr])
+//! 3. Returns a [Result] containing a [Response] or an [Err]
+
+use repline::{prebaked::read_and, Response};
+use std::{error::Error, str::FromStr};
+
+fn main() -> Result<(), Box<dyn Error>> {
+    read_and("\x1b[33m", "  >", " ?>", |line| {
+        println!("-> {:?}", f64::from_str(line.trim())?);
+        Ok(Response::Accept)
+    })?;
+    Ok(())
+}

sample-code/sqrt.cl

@@ -0,0 +1,56 @@
+#!/usr/bin/env conlang-run
+//! Square root approximation, and example applications
+
+/// A really small nonzero number
+const EPSILON: f64 = 8.8541878188 / 1000000000000.0;
+
+/// Calcuates the absolute value of a number
+fn f64_abs(n: f64) -> f64 {
+    let n = n as f64
+    if n < (0.0) { -n } else { n }
+}
+
+/// Square root approximation using Newton's method
+fn sqrt(n: f64) -> f64 {
+    let n = n as f64
+    if n < 0.0 {
+        return 0.0 / 0.0 // TODO: NaN constant
+    }
+    if n == 0.0 {
+        return 0.0
+    }
+
+    let z = n
+    loop {
+        let adj = (z * z - n) / (2.0 * z)
+        z -= adj
+        if adj.f64_abs() < EPSILON {
+            break z;
+        }
+    }
+}
+
+/// Pythagorean theorem: a² + b² = c²
+fn pythag(a: f64, b: f64) -> f64 {
+    sqrt(a * a + b * b)
+}
+
+/// Quadratic formula: (-b ± √(b² - 4ac)) / 2a
+fn quadratic(a: f64, b: f64, c: f64) -> (f64, f64) {
+    let a = a as f64; let b = b as f64; let c = c as f64;
+    (
+        (-b + sqrt(b * b - 4.0 * a * c)) / 2.0 * a,
+        (-b - sqrt(b * b - 4.0 * a * c)) / 2.0 * a,
+    )
+}
+
+fn main() {
+    for i in 0..10 {
+        println("sqrt(",i,") ≅ ",sqrt(i as f64))
+    }
+    println("\nPythagorean Theorem")
+    println("Hypotenuse of ⊿(5, 12): ", pythag(5.0, 12.0))
+
+    println("\nQuadratic formula")
+    println("Roots of 10x² + 4x - 1: ", quadratic(10.0, 44.0, -1.0))
+}