diff options
Diffstat (limited to 'src/vm.rs')
| -rw-r--r-- | src/vm.rs | 102 |
1 files changed, 92 insertions, 10 deletions
@@ -3,6 +3,7 @@ use std::collections::HashMap; use std::fmt::Debug; use std::path::{Path, PathBuf}; use std::rc::Rc; +use std::cell::RefCell; use crate::compiler::Type; use crate::error::{Error, ErrorKind}; @@ -22,11 +23,53 @@ pub enum Value { Int(i64), Bool(bool), String(Rc<String>), - Function(Rc<Block>), + Function(Vec<Rc<RefCell<UpValue>>>, Rc<Block>), Unkown, Nil, } +#[derive(Clone, Debug)] +pub struct UpValue { + slot: usize, + value: Value, +} + +impl UpValue { + + fn new(value: usize) -> Self { + Self { + slot: value, + value: Value::Nil, + } + } + + fn get(&self, stack: &[Value]) -> Value { + if self.is_closed() { + self.value.clone() + } else { + stack[self.slot].clone() + } + } + + fn set(&mut self, stack: &mut [Value], value: Value) { + if self.is_closed() { + self.value = value; + } else { + stack[self.slot] = value; + } + } + + + fn is_closed(&self) -> bool { + self.slot == 0 + } + + fn close(&mut self, value: Value) { + self.slot = 0; + self.value = value; + } +} + impl Debug for Value { fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { match self { @@ -34,7 +77,7 @@ impl Debug for Value { Value::Int(i) => write!(fmt, "(int {})", i), Value::Bool(b) => write!(fmt, "(bool {})", b), Value::String(s) => write!(fmt, "(string \"{}\")", s), - Value::Function(block) => write!(fmt, "(fn {}: {:?})", block.name, block.ty), + Value::Function(_, block) => write!(fmt, "(fn {}: {:?})", block.name, block.ty), Value::Unkown => write!(fmt, "(unkown)"), Value::Nil => write!(fmt, "(nil)"), } @@ -57,7 +100,7 @@ impl Value { Value::Int(_) => Type::Int, Value::Bool(_) => Type::Bool, Value::String(_) => Type::String, - Value::Function(block) => block.ty.clone(), + Value::Function(_, block) => block.ty.clone(), Value::Unkown => Type::UnknownType, Value::Nil => Type::Void, } @@ -69,6 +112,7 @@ pub enum Op { Illegal, Pop, + PopUpvalue, Constant(Value), Add, @@ -92,7 +136,10 @@ pub enum Op { Unreachable, ReadLocal(usize), - Assign(usize), + AssignLocal(usize), + + ReadUpvalue(usize), + AssignUpvalue(usize), Define(Type), @@ -105,6 +152,7 @@ pub enum Op { #[derive(Debug)] pub struct Block { pub ty: Type, + pub ups: Vec<Type>, pub name: String, pub file: PathBuf, @@ -118,6 +166,7 @@ impl Block { pub fn new(name: &str, file: &Path, line: usize) -> Self { Self { ty: Type::Void, + ups: Vec::new(), name: String::from(name), file: file.to_owned(), ops: Vec::new(), @@ -222,6 +271,8 @@ struct Frame { #[derive(Debug)] pub struct VM { + upvalues: HashMap<usize, Rc<RefCell<UpValue>>>, + stack: Vec<Value>, frames: Vec<Frame>, print_blocks: bool, @@ -236,6 +287,7 @@ enum OpResult { impl VM { pub fn new() -> Self { Self { + upvalues: HashMap::new(), stack: Vec::new(), frames: Vec::new(), print_blocks: false, @@ -253,6 +305,11 @@ impl VM { self } + fn find_upvalue(&mut self, slot: usize) -> &mut Rc<RefCell<UpValue>> { + self.upvalues.entry(slot).or_insert( + Rc::new(RefCell::new(UpValue::new(slot)))) + } + fn pop(&mut self) -> Value { self.stack.pop().unwrap() } @@ -304,7 +361,11 @@ impl VM { } Op::Pop => { - self.stack.pop(); + self.stack.pop().unwrap(); + } + + Op::PopUpvalue => { + self.stack.pop().unwrap(); } Op::Constant(value) => { @@ -424,12 +485,33 @@ impl VM { self.stack.push(Value::Bool(true)); } + Op::ReadUpvalue(slot) => { + let offset = self.frame().stack_offset; + let value = match &self.stack[offset] { + Value::Function(ups, _) => { + ups[slot].borrow().get(&self.stack) + } + _ => unreachable!(), + }; + self.stack.push(value); + } + + Op::AssignUpvalue(slot) => { + let offset = self.frame().stack_offset; + let value = self.stack.pop().unwrap(); + let slot = match &self.stack[offset] { + Value::Function(ups, _) => Rc::clone(&ups[slot]), + _ => unreachable!(), + }; + slot.borrow_mut().set(&mut self.stack, value); + } + Op::ReadLocal(slot) => { let slot = self.frame().stack_offset + slot; self.stack.push(self.stack[slot].clone()); } - Op::Assign(slot) => { + Op::AssignLocal(slot) => { let slot = self.frame().stack_offset + slot; self.stack[slot] = self.stack.pop().unwrap(); } @@ -439,7 +521,7 @@ impl VM { Op::Call(num_args) => { let new_base = self.stack.len() - 1 - num_args; match &self.stack[new_base] { - Value::Function(block) => { + Value::Function(_, block) => { let args = block.args(); if args.len() != num_args { error!(self, @@ -501,7 +583,7 @@ impl VM { self.stack.clear(); self.frames.clear(); - self.stack.push(Value::Function(Rc::clone(&block))); + self.stack.push(Value::Function(Vec::new(), Rc::clone(&block))); self.frames.push(Frame { stack_offset: 0, @@ -565,7 +647,7 @@ impl VM { Op::Call(num_args) => { let new_base = self.stack.len() - 1 - num_args; match &self.stack[new_base] { - Value::Function(block) => { + Value::Function(_, block) => { let args = block.args(); if args.len() != num_args { error!(self, @@ -612,7 +694,7 @@ impl VM { self.stack.clear(); self.frames.clear(); - self.stack.push(Value::Function(Rc::clone(&block))); + self.stack.push(Value::Function(Vec::new(), Rc::clone(&block))); for arg in block.args() { self.stack.push(arg.as_value()); } |