From e49dbab859c8e135307d0ac1ab6be205c359ce13 Mon Sep 17 00:00:00 2001
From: Roman Godmaire <godmaire@twilit.io>
Date: Mon, 6 May 2024 08:50:38 -0400
Subject: [PATCH] feat: rudimentary float support

---
 src/env/core.rs     | 16 ++++++++++++++++
 src/evaluator.rs    |  5 +++++
 src/node.rs         |  2 ++
 src/parser/lexer.rs |  9 +++++++--
 src/parser/mod.rs   |  1 +
 5 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/src/env/core.rs b/src/env/core.rs
index 3ad505b..bb9d5f8 100644
--- a/src/env/core.rs
+++ b/src/env/core.rs
@@ -102,6 +102,10 @@ pub(super) fn core() -> HashMap<String, Node> {
                             Node::Int128(lhs as i128 + rhs as i128)
                         }
                         (Node::Int128(lhs), Node::Int(rhs)) => Node::Int128(lhs + rhs as i128),
+
+                        (Node::Float(lhs), Node::Float(rhs)) => Node::Float(lhs + rhs),
+                        (Node::Int(lhs), Node::Float(rhs)) => Node::Float(lhs as f64 + rhs),
+                        (Node::Float(lhs), Node::Int(rhs)) => Node::Float(lhs + rhs as f64),
                         _ => todo!(),
                     })
                     .unwrap_or(Node::Int(0));
@@ -124,6 +128,10 @@ pub(super) fn core() -> HashMap<String, Node> {
                             Node::Int128(lhs as i128 - rhs as i128)
                         }
                         (Node::Int128(lhs), Node::Int(rhs)) => Node::Int128(lhs - rhs as i128),
+
+                        (Node::Float(lhs), Node::Float(rhs)) => Node::Float(lhs - rhs),
+                        (Node::Float(lhs), Node::Int(rhs)) => Node::Float(lhs - rhs as f64),
+                        (Node::Int(lhs), Node::Float(rhs)) => Node::Float(lhs as f64 - rhs),
                         _ => todo!(),
                     })
                     .unwrap_or(Node::Int(0));
@@ -146,6 +154,10 @@ pub(super) fn core() -> HashMap<String, Node> {
                             Node::Int128(lhs as i128 * rhs as i128)
                         }
                         (Node::Int128(lhs), Node::Int(rhs)) => Node::Int128(lhs * rhs as i128),
+
+                        (Node::Float(lhs), Node::Float(rhs)) => Node::Float(lhs * rhs),
+                        (Node::Float(lhs), Node::Int(rhs)) => Node::Float(lhs * rhs as f64),
+                        (Node::Int(lhs), Node::Float(rhs)) => Node::Float(lhs as f64 * rhs),
                         _ => todo!(),
                     })
                     .unwrap_or(Node::Int(0));
@@ -168,6 +180,10 @@ pub(super) fn core() -> HashMap<String, Node> {
                             Node::Int128(lhs as i128 / rhs as i128)
                         }
                         (Node::Int128(lhs), Node::Int(rhs)) => Node::Int128(lhs / rhs as i128),
+
+                        (Node::Float(lhs), Node::Float(rhs)) => Node::Float(lhs / rhs),
+                        (Node::Float(lhs), Node::Int(rhs)) => Node::Float(lhs / rhs as f64),
+                        (Node::Int(lhs), Node::Float(rhs)) => Node::Float(lhs as f64 / rhs),
                         _ => todo!(),
                     })
                     .unwrap_or(Node::Int(0));
diff --git a/src/evaluator.rs b/src/evaluator.rs
index 31342ba..cbc5c10 100644
--- a/src/evaluator.rs
+++ b/src/evaluator.rs
@@ -109,6 +109,10 @@ mod test {
     #[case("(* 8 9)", "72")]
     #[case("(/ 86 2)", "43")]
     #[case("(+ 1 2 (- 3 4))", "2")]
+    #[case("(+ 1 0.5)", "1.5")]
+    #[case("(- 1 0.5)", "0.5")]
+    #[case("(* 1 0.5)", "0.5")]
+    #[case("(/ 1.0 2.0)", "0.5")]
     // Native functions defaults
     #[case("(+)", "0")]
     #[case("(-)", "0")]
@@ -198,6 +202,7 @@ mod test {
     #[case("(str (+ 1 2))", "3")]
     #[case("(str (list 1 2 3))", "(1 2 3)")]
     fn test_evaluator(#[case] input: &str, #[case] expected: &str) {
+        dbg!(input);
         let env = Environment::default();
         let ast = parser::parse_str(input).unwrap();
         let res = eval(&env, ast)
diff --git a/src/node.rs b/src/node.rs
index c8865ef..940daf8 100644
--- a/src/node.rs
+++ b/src/node.rs
@@ -12,6 +12,7 @@ pub enum Node {
     Keyword(String),
     Int(i64),
     Int128(i128),
+    Float(f64),
     String(String),
     Boolean(bool),
     Nil,
@@ -44,6 +45,7 @@ impl std::fmt::Display for Node {
 
             Node::Int(val) => write!(f, "{}", val),
             Node::Int128(val) => write!(f, "{}", val),
+            Node::Float(val) => write!(f, "{}", val),
             Node::Boolean(true) => write!(f, "true"),
             Node::Boolean(false) => write!(f, "false"),
             Node::Symbol(val) => write!(f, "{}", val),
diff --git a/src/parser/lexer.rs b/src/parser/lexer.rs
index 5735c02..133afc8 100644
--- a/src/parser/lexer.rs
+++ b/src/parser/lexer.rs
@@ -34,6 +34,7 @@ pub enum Token {
     // Values
     Keyword(String),
     Int(i64),
+    Float(f64),
     String(String),
     Ident(String),
     True,
@@ -178,14 +179,18 @@ fn read_int(input: &mut Peekable<Chars>, first: char) -> Token {
             continue;
         }
 
-        if !c.is_ascii_digit() {
+        if !c.is_ascii_digit() && *c != '.' {
             break;
         }
 
         raw_int.push(input.next().unwrap());
     }
 
-    Token::Int(raw_int.iter().collect::<String>().parse::<i64>().unwrap())
+    if raw_int.iter().any(|c| *c == '.') {
+        Token::Float(raw_int.iter().collect::<String>().parse::<f64>().unwrap())
+    } else {
+        Token::Int(raw_int.iter().collect::<String>().parse::<i64>().unwrap())
+    }
 }
 
 fn read_ident(input: &mut Peekable<Chars>, first: char) -> Token {
diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index 8699f01..d711fb5 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -60,6 +60,7 @@ fn next_statement(tokens: &mut Peekable<IntoIter<Token>>) -> Result<Option<Node>
         Token::Ident(val) => Node::Symbol(val),
         Token::String(val) => Node::String(val),
         Token::Int(int) => Node::Int(int),
+        Token::Float(float) => Node::Float(float),
         Token::True => Node::Boolean(true),
         Token::False => Node::Boolean(false),
         Token::Nil => Node::Nil,