hello world!

clippy.toml

@@ -1,5 +1,4 @@
 disallowed-types = [
-    { path = "std::collections::HashMap", reason = "may be fxhash or siphash, depending on the feature, stay flexible" },
-    { path = "std::collections::HashSet", reason = "may be fxhash or siphash, depending on the feature, stay flexible" },
-    { path = "std::collections::Vec", reason = "we generally want to use bumpalos collections" },
+    "std::collections::HashMap",
+    "std::collections::HashSet",
 ]

src/ast.rs

@@ -112,7 +112,7 @@ impl Expr<'_> {
 
 #[derive(Debug, PartialEq)]
 pub enum Literal<'ast> {
-    String(&'ast str, Span),
+    String(Symbol, Span),
     Number(f64, Span),
     Array(Vec<'ast, Expr<'ast>>, Span),
     Object(Span),

src/bytecode.rs

@@ -1,26 +1,25 @@
 //! The bytecode that is executed in the vm
 
 use crate::errors::Span;
-use crate::gc::Symbol;
-use crate::HashMap;
+use crate::vm::Value;
 use bumpalo::collections::Vec;
 
 #[derive(Debug)]
 pub struct FnBlock<'bc> {
-    pub code: Vec<'bc, Instr<'bc>>,
+    pub code: Vec<'bc, Instr>,
     pub stack_sizes: Vec<'bc, usize>,
     pub spans: Vec<'bc, Span>,
     pub arity: u8,
 }
 
 #[derive(Debug, Clone, Copy)]
-pub enum Instr<'bc> {
+pub enum Instr {
     /// Store the current value on the stack to the stack location with the local offset `usize`
     Store(usize),
     /// Load the variable value from the local offset `usize` onto the stack
     Load(usize),
     /// Push a value onto the stack
-    PushVal(&'bc Value),
+    PushVal(Value),
     /// Negate the top value on the stack. Only works with numbers and booleans
     Neg,
     BinAdd,
@@ -40,13 +39,3 @@ pub enum Instr<'bc> {
     /// Println the value on top of the stack
     Print,
 }
-
-#[derive(Debug)]
-pub enum Value {
-    Null,
-    Bool(bool),
-    Num(f64),
-    String,
-    Array,
-    Object(HashMap<Symbol, Value>),
-}

src/compile.rs

@@ -4,10 +4,11 @@ use crate::ast::{
     Assignment, BinaryOp, BinaryOpKind, Block, Call, Declaration, Expr, FnDecl, Ident, IfStmt,
     Literal, Program, Stmt, UnaryOp, WhileStmt,
 };
-use crate::bytecode::{FnBlock, Instr, Value};
+use crate::bytecode::{FnBlock, Instr};
 use crate::errors::{CompilerError, Span};
 use crate::gc::Symbol;
-use crate::HashMap;
+use crate::vm::Value;
+use crate::{HashMap, RtAlloc};
 use bumpalo::collections::Vec;
 use bumpalo::Bump;
 use std::cell::RefCell;
@@ -49,23 +50,26 @@ impl Env<'_> {
 }
 
 #[derive(Debug)]
-struct Compiler<'ast, 'bc> {
+struct Compiler<'ast, 'bc, 'gc> {
     blocks: Vec<'bc, FnBlock<'bc>>,
     current_block: usize,
     bump: &'bc Bump,
     /// the current local variables that are in scope, only needed for compiling
     env: Rc<RefCell<Env<'ast>>>,
+    rt: &'gc mut RtAlloc,
 }
 
-pub fn compile<'bc>(
-    ast: &Program,
+pub fn compile<'ast, 'bc, 'gc>(
+    ast: &'ast Program,
     bytecode_bump: &'bc Bump,
+    rt: &'gc mut RtAlloc,
 ) -> Result<Vec<'bc, FnBlock<'bc>>, CompilerError> {
     let mut compiler = Compiler {
         blocks: Vec::new_in(bytecode_bump),
         current_block: 0,
         bump: bytecode_bump,
         env: Rc::new(RefCell::new(Default::default())),
+        rt,
     };
 
     compiler.compile(ast)?;
@@ -73,7 +77,7 @@ pub fn compile<'bc>(
     Ok(compiler.blocks)
 }
 
-impl<'ast, 'bc> Compiler<'ast, 'bc> {
+impl<'ast, 'bc, 'gc> Compiler<'ast, 'bc, 'gc> {
     fn compile(&mut self, ast: &'ast Program<'ast>) -> CResult<()> {
         let global_block = FnBlock {
             code: Vec::new_in(self.bump),
@@ -199,7 +203,7 @@ impl<'ast, 'bc> Compiler<'ast, 'bc> {
 
     fn compile_expr_literal(&mut self, lit: &Literal) -> CResult<()> {
         let value = match lit {
-            Literal::String(_str, _) => Value::String,
+            Literal::String(str, _) => Value::String(*str),
             Literal::Number(num, _) => Value::Num(*num),
             Literal::Array(vec, _) => {
                 if vec.is_empty() {
@@ -208,16 +212,12 @@ impl<'ast, 'bc> Compiler<'ast, 'bc> {
                     todo!()
                 }
             }
-            Literal::Object(_) => Value::Object(HashMap::default()),
+            Literal::Object(_) => Value::Object(self.rt.alloc_obj(HashMap::default())),
             Literal::Boolean(bool, _) => Value::Bool(*bool),
             Literal::Null(_) => Value::Null,
         };
 
-        self.push_instr(
-            Instr::PushVal(self.bump.alloc(value)),
-            StackChange::Grow,
-            lit.span(),
-        );
+        self.push_instr(Instr::PushVal(value), StackChange::Grow, lit.span());
 
         Ok(())
     }
@@ -232,7 +232,6 @@ impl<'ast, 'bc> Compiler<'ast, 'bc> {
     }
 
     fn compile_expr_binary(&mut self, binary: &BinaryOp) -> CResult<()> {
-        // todo: is this the correct ordering?
         self.compile_expr(&binary.lhs)?;
         self.compile_expr(&binary.rhs)?;
 
@@ -267,7 +266,7 @@ impl<'ast, 'bc> Compiler<'ast, 'bc> {
         *block.stack_sizes.last().expect("empty stack") - 1
     }
 
-    fn push_instr(&mut self, instr: Instr<'bc>, stack_change: StackChange, span: Span) {
+    fn push_instr(&mut self, instr: Instr, stack_change: StackChange, span: Span) {
         let block = &mut self.blocks[self.current_block];
         let stack_top = block.stack_sizes.last().copied().unwrap_or(0);
         let new_stack_top = stack_top as isize + stack_change as isize;

src/gc.rs

@@ -1,6 +1,7 @@
 #![allow(dead_code)]
 
-use crate::HashSet;
+use crate::vm::Value;
+use crate::{HashMap, HashSet};
 use std::collections::LinkedList;
 use std::fmt::{Debug, Formatter};
 use std::hash::{Hash, Hasher};
@@ -41,12 +42,91 @@ impl<T: ?Sized> Clone for Gc<T> {
 
 impl<T: ?Sized> Copy for Gc<T> {}
 
-/// An interned String. Hashing and Equality are O(1) and just look at the pointer address
+/// An reference to an interned String. Hashing and Equality are O(1) and just look at the pointer address
 #[derive(Clone, Copy)]
 pub struct Symbol {
     gc: Gc<str>,
 }
 
+type ObjectMap = HashMap<Symbol, Value>;
+
+/// A reference to an Object on the heap.
+/// ```js
+/// let x = {};
+/// ```
+/// This is inside the local x now.
+#[derive(Clone, Copy)]
+pub struct Object {
+    gc: Gc<HeapObject>,
+}
+
+#[derive(Debug)]
+#[repr(C)]
+struct HeapObject {
+    kind: HeapObjectKind,
+}
+
+#[derive(Debug)]
+enum HeapObjectKind {
+    String(Gc<str>),
+    Object(ObjectMap),
+}
+
+#[derive(Debug)]
+pub struct RtAlloc {
+    symbols: HashSet<NonNull<str>>,
+    objects: LinkedList<HeapObject>,
+}
+
+impl RtAlloc {
+    /// # Safety
+    /// Promise to not forget to mark any roots and to not deref `Gc<T>` after you've dropped me 🥺
+    pub unsafe fn new() -> Self {
+        Self {
+            symbols: HashSet::default(),
+            objects: LinkedList::new(),
+        }
+    }
+
+    fn alloc_str(&mut self, str: &str) -> Gc<str> {
+        let ptr = Box::into_raw(str.to_owned().into_boxed_str());
+        // SAFETY: Box cannot be null
+        let new_nonnull = unsafe { NonNull::new_unchecked(ptr) };
+        let gc = Gc { ptr: new_nonnull };
+        let object = HeapObject {
+            kind: HeapObjectKind::String(gc),
+        };
+
+        self.objects.push_back(object);
+
+        gc
+    }
+
+    pub fn alloc_obj(&mut self, obj: ObjectMap) -> Object {
+        self.objects.push_back(HeapObject {
+            kind: HeapObjectKind::Object(obj),
+        });
+
+        let ptr = self.objects.back().unwrap();
+
+        Object {
+            gc: Gc {
+                ptr: NonNull::from(ptr),
+            },
+        }
+    }
+
+    pub fn intern_string(&mut self, str: &str) -> Symbol {
+        let original_nonnull = NonNull::from(str);
+
+        if let Some(interned) = self.symbols.get(&original_nonnull) {
+            Symbol::new(Gc { ptr: *interned })
+        } else {
+            Symbol::new(self.alloc_str(str))
+        }
+    }
+}
+
 impl Symbol {
     pub fn new(gc: Gc<str>) -> Self {
         Self { gc }
@@ -89,53 +169,19 @@ impl Debug for Symbol {
     }
 }
 
-#[derive(Debug)]
-struct Object {
-    kind: ObjectKind,
-}
+impl Deref for Object {
+    type Target = ObjectMap;
 
-#[derive(Debug)]
-enum ObjectKind {
-    String(Gc<str>),
-}
-
-#[derive(Debug)]
-pub struct RtAlloc {
-    symbols: HashSet<NonNull<str>>,
-    objects: LinkedList<Object>,
-}
-
-impl RtAlloc {
-    /// # Safety
-    /// Promise to not forget to mark any roots and to not deref `Gc<T>` after you've dropped me 🥺
-    pub unsafe fn new() -> Self {
-        Self {
-            symbols: HashSet::default(),
-            objects: LinkedList::new(),
+    fn deref(&self) -> &Self::Target {
+        match self.gc.deref().kind {
+            HeapObjectKind::Object(ref map) => map,
+            _ => unreachable!(),
         }
     }
+}
 
-    fn alloc_str(&mut self, str: &str) -> Gc<str> {
-        let ptr = Box::into_raw(str.to_owned().into_boxed_str());
-        // SAFETY: Box cannot be null
-        let new_nonnull = unsafe { NonNull::new_unchecked(ptr) };
-        let gc = Gc { ptr: new_nonnull };
-        let object = Object {
-            kind: ObjectKind::String(gc.clone()),
-        };
-
-        self.objects.push_back(object);
-
-        gc
-    }
-
-    pub fn intern_string(&mut self, str: &str) -> Symbol {
-        let original_nonnull = NonNull::from(str);
-
-        if let Some(interned) = self.symbols.get(&original_nonnull) {
-            return Symbol::new(Gc { ptr: *interned });
-        }
-
-        Symbol::new(self.alloc_str(str))
+impl Debug for Object {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        self.gc.deref().fmt(f)
     }
 }

src/lex.rs

@@ -128,7 +128,7 @@ impl<'code, 'gc> Lexer<'code, 'gc> {
             .unwrap_or(false)
     }
 
-    fn maybe_next_char<'a>(
+    fn maybe_next_char(
         &mut self,
         expect_char: char,
         true_type: TokenKind,

src/lib.rs

@@ -45,18 +45,21 @@ pub fn run_program(program: &str) {
     }
 }
 
-fn process_ast(program: &str, ast: Program, runtime: RtAlloc) {
+fn process_ast(program: &str, ast: Program, mut runtime: RtAlloc) {
     println!("AST:\n{:?}\n", ast);
 
     let bytecode_alloc = Bump::new();
 
-    let bytecode = compile::compile(&ast, &bytecode_alloc);
+    let bytecode = compile::compile(&ast, &bytecode_alloc, &mut runtime);
 
     match bytecode {
         Ok(code) => {
             println!("Bytecode:\n{:#?}\n", code);
 
-            let _result_lol = vm::execute(&code, runtime);
+            let result = vm::execute(&code, runtime);
+            if let Err(result) = result {
+                eprintln!("error: {}", result);
+            }
         }
         Err(err) => errors::display_error(program, err),
     }

src/parse.rs

@@ -525,10 +525,7 @@ where
 
         let next = self.next().ok_or_else(|| CompilerError::eof("primary"))?;
         let return_expr = match next.kind {
-            TokenKind::String(literal) => Ok(Expr::Literal(Literal::String(
-                self.bump.alloc_str(&literal),
-                next.span,
-            ))),
+            TokenKind::String(literal) => Ok(Expr::Literal(Literal::String(literal, next.span))),
             TokenKind::Number(literal) => Ok(Expr::Literal(Literal::Number(literal, next.span))),
             TokenKind::False => Ok(Expr::Literal(Literal::Boolean(false, next.span))),
             TokenKind::True => Ok(Expr::Literal(Literal::Boolean(true, next.span))),
@@ -612,13 +609,14 @@ where
         let expr = parser(self)?;
         elements.push(expr);
 
-        while self.peek_kind().ok_or_else(|| {
+        let reached_eof = || {
             CompilerError::new(
                 Span::dummy(),
                 format!("reached EOF expecting `{:?}`", close.clone()),
             )
-        })? != &close
-        {
+        };
+
+        while self.peek_kind().ok_or_else(reached_eof)? != &close {
             self.expect(TokenKind::Comma)?;
 
             // trailing comma support

src/vm.rs

@@ -1,20 +1,146 @@
-use crate::bytecode::FnBlock;
-use crate::gc::RtAlloc;
+use crate::bytecode::{FnBlock, Instr};
+use crate::gc::{Object, RtAlloc, Symbol};
+use std::fmt::{Debug, Display, Formatter};
 
-type VmResult = Result<(), ()>;
+type VmError = &'static str;
+type VmResult = Result<(), VmError>;
 
-pub fn execute<'bc>(bytecode: &'bc [FnBlock<'bc>], alloc: RtAlloc) -> Result<(), ()> {
-    let _vm = Vm {
-        blocks: bytecode,
-        current: bytecode.first().ok_or(())?,
-        alloc,
+pub fn execute<'bc>(bytecode: &'bc [FnBlock<'bc>], alloc: RtAlloc) -> Result<(), VmError> {
+    let mut vm = Vm {
+        _blocks: bytecode,
+        current: bytecode.first().ok_or("no bytecode found")?,
+        pc: 0,
+        stack: Vec::with_capacity(1024 << 5),
+        _alloc: alloc,
     };
 
-    Ok(())
+    vm.execute_function()
+}
+
+#[derive(Debug, Clone, Copy)]
+pub enum Value {
+    Null,
+    Bool(bool),
+    Num(f64),
+    String(Symbol),
+    Array,
+    Object(Object),
+}
+
+const _: () = _check_val_size();
+const fn _check_val_size() {
+    if std::mem::size_of::<Value>() != 24 {
+        panic!("value got bigger!");
+    }
 }
 
 struct Vm<'bc> {
-    blocks: &'bc [FnBlock<'bc>],
+    _blocks: &'bc [FnBlock<'bc>],
     current: &'bc FnBlock<'bc>,
-    alloc: RtAlloc,
+    _alloc: RtAlloc,
+    pc: usize,
+    stack: Vec<Value>,
+}
+
+impl<'bc> Vm<'bc> {
+    fn execute_function(&mut self) -> VmResult {
+        let code = &self.current.code;
+
+        loop {
+            let instr = code.get(self.pc);
+            match instr {
+                Some(&instr) => self.dispatch_instr(instr)?,
+                None => return Ok(()),
+            }
+            self.pc += 1;
+        }
+    }
+
+    fn dispatch_instr(&mut self, instr: Instr) -> VmResult {
+        match instr {
+            Instr::Store(index) => {
+                let val = self.stack.pop().unwrap();
+                self.stack.insert(index, val);
+            }
+            Instr::Load(index) => self.stack.push(self.stack[index]),
+            Instr::PushVal(value) => self.stack.push(value),
+            Instr::Neg => {
+                let val = self.stack.pop().unwrap();
+                match val {
+                    Value::Bool(bool) => self.stack.push(Value::Bool(!bool)),
+                    Value::Num(float) => self.stack.push(Value::Num(-float)),
+                    _ => return Err(self.type_error()),
+                }
+            }
+            Instr::BinAdd => self.bin_op(|lhs, rhs| match (lhs, rhs) {
+                (Value::Num(a), Value::Num(b)) => Ok(Value::Num(a + b)),
+                _ => Err("bad type"),
+            })?,
+            Instr::BinSub => self.bin_op(|lhs, rhs| match (lhs, rhs) {
+                (Value::Num(a), Value::Num(b)) => Ok(Value::Num(a - b)),
+                _ => Err("bad type"),
+            })?,
+            Instr::BinMul => self.bin_op(|lhs, rhs| match (lhs, rhs) {
+                (Value::Num(a), Value::Num(b)) => Ok(Value::Num(a * b)),
+                _ => Err("bad type"),
+            })?,
+            Instr::BinDiv => self.bin_op(|lhs, rhs| match (lhs, rhs) {
+                (Value::Num(a), Value::Num(b)) => Ok(Value::Num(a / b)),
+                _ => Err("bad type"),
+            })?,
+            Instr::BinMod => self.bin_op(|lhs, rhs| match (lhs, rhs) {
+                (Value::Num(a), Value::Num(b)) => Ok(Value::Num(a % b)),
+                _ => Err("bad type"),
+            })?,
+            Instr::BinAnd => self.bin_op(|lhs, rhs| match (lhs, rhs) {
+                (Value::Bool(a), Value::Bool(b)) => Ok(Value::Bool(a && b)),
+                _ => Err("bad type"),
+            })?,
+            Instr::BinOr => self.bin_op(|lhs, rhs| match (lhs, rhs) {
+                (Value::Bool(a), Value::Bool(b)) => Ok(Value::Bool(a || b)),
+                _ => Err("bad type"),
+            })?,
+            Instr::CmpGreater => todo!(),
+            Instr::CmpGreaterEq => todo!(),
+            Instr::CmpLess => todo!(),
+            Instr::CmpLessEq => todo!(),
+            Instr::CmpEq => todo!(),
+            Instr::CmpNotEq => todo!(),
+            Instr::Print => {
+                let val = self.stack.pop().unwrap();
+                println!("{}", val);
+            }
+        }
+
+        Ok(())
+    }
+
+    fn bin_op<F>(&mut self, f: F) -> VmResult
+    where
+        F: FnOnce(Value, Value) -> Result<Value, VmError>,
+    {
+        let rhs = self.stack.pop().unwrap();
+        let lhs = self.stack.pop().unwrap();
+
+        let result = f(lhs, rhs)?;
+        self.stack.push(result);
+        Ok(())
+    }
+
+    fn type_error(&self) -> VmError {
+        "bad type"
+    }
+}
+
+impl Display for Value {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Value::Null => f.write_str("null"),
+            Value::Bool(bool) => Display::fmt(bool, f),
+            Value::Num(num) => Display::fmt(num, f),
+            Value::String(str) => f.write_str(str.as_str()),
+            Value::Array => todo!(),
+            Value::Object(_) => todo!(),
+        }
+    }
 }

test.dil

@@ -1,10 +1 @@
-let x = 2 * 3;
-
-let tz = x * 5;
-
-{
-    let uwu = 5;
-    uwu;
-}
-
-print 5 + 5;
+print "Hello World!";