make some progress: atoms and ifs

src/compiler.rs

@@ -6,14 +6,37 @@ use num_derive::{FromPrimitive, ToPrimitive};
 use num_traits::FromPrimitive;
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq, FromPrimitive, ToPrimitive)]
-enum Op {
+pub enum Op {
     Return,
     Constant,
+    Jump,
+    JumpIfFalse,
+}
+
+impl std::fmt::Display for Op {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        use Op::*;
+        match self {
+            Return => write!(f, "return"),
+            Constant => write!(f, "constant"),
+            Jump => write!(f, "jump"),
+            JumpIfFalse => write!(f, "jump_if_false"),
+        }
+    }
 }
 
 #[derive(Clone, Debug, PartialEq)]
-struct Chunk<'a> {
-    pub constants: Vec<Value<'a>>,
+pub struct Local {
+    name: &'static str,
+    depth: u8,
+}
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct Chunk<'a> {
+    pub locals: Vec<Local>,
+    scope_depth: usize,
+    local_count: usize,
+    pub constants: Vec<Value>,
     pub bytecode: Vec<u8>,
     pub spans: Vec<SimpleSpan>,
     pub strings: Vec<&'static str>,
@@ -26,7 +49,34 @@ struct Chunk<'a> {
 }
 
 impl<'a> Chunk<'a> {
-    fn visit(&mut self, node: &'a Spanned<Ast>) {
+    pub fn new(ast: &'a Spanned<Ast>, name: &'static str, src: &'static str) -> Chunk<'a> {
+        Chunk {
+            locals: vec![],
+            scope_depth: 0,
+            local_count: 0,
+            constants: vec![],
+            bytecode: vec![],
+            spans: vec![],
+            strings: vec![],
+            keywords: vec![
+                "nil", "bool", "number", "keyword", "string", "tuple", "list", "",
+            ],
+            nodes: vec![],
+            ast: &ast.0,
+            span: ast.1,
+            src,
+            name,
+        }
+    }
+
+    pub fn kw_from(&self, kw: &str) -> Option<Value> {
+        self.keywords
+            .iter()
+            .position(|s| *s == kw)
+            .map(Value::Keyword)
+    }
+
+    pub fn visit(&mut self, node: &'a Spanned<Ast>) {
         let root_node = self.ast;
         let root_span = self.span;
         let (ast, span) = node;
@@ -37,7 +87,7 @@ impl<'a> Chunk<'a> {
         self.span = root_span;
     }
 
-    fn emit_constant(&mut self, val: Value<'a>) {
+    fn emit_constant(&mut self, val: Value) {
         let constant_index = self.constants.len();
         if constant_index > u8::MAX as usize {
             panic!(
@@ -57,39 +107,78 @@ impl<'a> Chunk<'a> {
         self.spans.push(self.span);
     }
 
-    fn compile(&mut self) {
+    pub fn compile(&mut self) {
+        use Ast::*;
         match self.ast {
-            Ast::Nil => self.emit_constant(Value::Nil),
-            Ast::Number(n) => self.emit_constant(Value::Number(*n)),
-            Ast::Boolean(b) => self.emit_constant(Value::Boolean(*b)),
-            Ast::String(s) => {
+            Nil => self.emit_constant(Value::Nil),
+            Number(n) => self.emit_constant(Value::Number(*n)),
+            Boolean(b) => self.emit_constant(if *b { Value::True } else { Value::False }),
+            String(s) => {
                 let str_index = self.strings.len();
                 self.strings.push(s);
-                self.emit_constant(Value::InternedString(s));
+                self.emit_constant(Value::Interned(str_index));
             }
-            Ast::Block(lines) => {
+            Keyword(s) => {
+                let existing_kw = self.keywords.iter().position(|kw| kw == s);
+                let kw_index = match existing_kw {
+                    Some(index) => index,
+                    None => self.keywords.len(),
+                };
+                self.keywords.push(s);
+                self.emit_constant(Value::Keyword(kw_index));
+            }
+            Block(lines) => {
+                self.scope_depth += 1;
                 for expr in lines {
                     self.visit(expr);
                 }
                 self.emit_op(Op::Return);
+                self.scope_depth -= 1;
             }
+            If(cond, then, r#else) => {
+                self.visit(cond);
+                let jif_idx = self.bytecode.len();
+                self.emit_op(Op::JumpIfFalse);
+                self.bytecode.push(0xff);
+                self.visit(then);
+                let jump_idx = self.bytecode.len();
+                self.emit_op(Op::Jump);
+                self.bytecode.push(0xff);
+                self.visit(r#else);
+                let end_idx = self.bytecode.len();
+                let jif_offset = jump_idx - jif_idx;
+                let jump_offset = end_idx - jump_idx;
+                self.bytecode[jif_idx + 1] = jif_offset as u8;
+                self.bytecode[jump_idx + 1] = jump_offset as u8;
+            }
+            // Let(patt, expr) => {
+            //     self.visit(expr);
+            //     self.visit(patt);
+            // }
+            // WordPattern(name) => {}
+            // PlaceholderPattern => {}
             _ => todo!(),
         }
     }
 
-    fn disassemble(&self) {
+    pub fn disassemble(&self) {
         println!("=== chunk: {} ===", self.name);
+        println!("IDX | CODE           | INFO");
         let mut codes = self.bytecode.iter().enumerate();
         while let Some((i, byte)) = codes.next() {
-            let op = Op::from_u8(*byte);
+            let op = Op::from_u8(*byte).unwrap();
+            use Op::*;
             match op {
-                Some(Op::Return) => println!("{i:04}: {byte:16}"),
-                Some(Op::Constant) => {
+                Return => println!("{i:04}: {op}"),
+                Constant => {
                     let (_, next) = codes.next().unwrap();
-                    let value = &self.constants[*next as usize];
-                    println!("i:04: {byte:16} {next:16} {value}")
+                    let value = &self.constants[*next as usize].show(self);
+                    println!("{i:04}: {:16} {next:04}: {value}", op.to_string());
+                }
+                Jump | JumpIfFalse => {
+                    let (_, next) = codes.next().unwrap();
+                    println!("{i:04}: {:16} {next:04}", op.to_string())
                 }
-                _ => unreachable!(),
             }
         }
     }

src/validator.rs

@@ -53,9 +53,9 @@ fn match_arities(arities: &HashSet<Arity>, num_args: u8) -> bool {
 }
 
 #[derive(Debug, PartialEq)]
-pub struct Validator<'a, 'src> {
+pub struct Validator<'a> {
     pub locals: Vec<(String, Span, FnInfo)>,
-    pub prelude: &'a Vec<(String, Value<'src>)>,
+    pub prelude: &'a Vec<(&'static str, Value)>,
     pub input: &'static str,
     pub src: &'static str,
     pub ast: &'a Ast,
@@ -65,14 +65,14 @@ pub struct Validator<'a, 'src> {
     status: VStatus,
 }
 
-impl<'a, 'src: 'a> Validator<'a, 'src> {
+impl<'a> Validator<'a> {
     pub fn new(
         ast: &'a Ast,
         span: Span,
         input: &'static str,
         src: &'static str,
-        prelude: &'a Vec<(String, Value<'src>)>,
-    ) -> Validator<'a, 'src> {
+        prelude: &'a Vec<(&'static str, Value)>,
+    ) -> Validator<'a> {
         Validator {
             input,
             src,
@@ -109,7 +109,7 @@ impl<'a, 'src: 'a> Validator<'a, 'src> {
 
     fn resolved(&self, name: &str) -> bool {
         self.locals.iter().any(|(bound, ..)| name == bound.as_str())
-            || self.prelude.iter().any(|(bound, _)| name == bound.as_str())
+            || self.prelude.iter().any(|(bound, _)| name == *bound)
     }
 
     fn bound(&self, name: &str) -> Option<&(String, Span, FnInfo)> {

src/value.rs

@@ -25,23 +25,60 @@ pub struct LFn {
 #[derive(Clone, Debug, PartialEq)]
 pub enum Value {
     Nil,
-    Boolean(bool),
+    True,
+    False,
     Keyword(usize), // use an idx, rather than a raw index
     Interned(usize),
     FnDecl(usize),
     String(Rc<String>),
     Number(f64),
+    Tuple(Rc<Vec<Value>>),
+    TupleStart { len: u8, size: u16 },
+    TupleEnd { len: u8, size: u16 },
     List(Box<Vector<Value>>),
-    Dict(Box<HashMap<&'static str, Value>>),
+    Dict(Box<HashMap<usize, Value>>),
     Box(Rc<LBox>),
     Fn(Rc<RefCell<LFn>>),
 }
 
 impl Value {
-    fn show(&self, ctx: &Chunk) -> String {
+    pub fn show(&self, ctx: &Chunk) -> String {
         use Value::*;
         match &self {
-            Nil => format!("nil"),
+            Nil => "nil".to_string(),
+            True => "true".to_string(),
+            False => "false".to_string(),
+            Number(n) => format!("{n}"),
+            Interned(i) => {
+                let str_str = ctx.strings[*i];
+                format!("\"{str_str}\"")
+            }
+            Keyword(i) => {
+                let kw_str = ctx.keywords[*i];
+                format!(":{kw_str}")
+            }
+            Tuple(t) => {
+                let members = t.iter().map(|e| e.show(ctx)).collect::<Vec<_>>().join(", ");
+                format!("({members})")
+            }
+            List(l) => {
+                let members = l.iter().map(|e| e.show(ctx)).collect::<Vec<_>>().join(", ");
+                format!("[{members}]")
+            }
+            Dict(d) => {
+                let members = d
+                    .iter()
+                    .map(|(k, v)| {
+                        let key_show = Value::Keyword(*k).show(ctx);
+                        let value_show = v.show(ctx);
+                        format!("{key_show} {value_show}")
+                    })
+                    .collect::<Vec<_>>()
+                    .join(", ");
+                format!("#{{{members}}}")
+            }
+            String(s) => s.as_ref().clone(),
+            _ => todo!(),
         }
     }
 }