finished resolver (chapter 11) and started classes (chapter 12)

This commit is contained in:
Moritz Gmeiner 2023-01-28 01:11:55 +01:00
commit 10540708d4
34 changed files with 1449 additions and 439 deletions

312
Cargo.lock generated
View file

@ -2,6 +2,152 @@
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@ -44,6 +190,30 @@ dependencies = [
"siphasher",
]
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name = "proc-macro-error"
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dependencies = [
"proc-macro2",
"quote",
"version_check",
]
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name = "proc-macro2"
version = "1.0.50"
@ -81,16 +251,55 @@ checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
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]
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version = "0.1.0"
dependencies = [
"itertools",
"phf",
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]
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version = "0.1.0"
dependencies = [
"itertools",
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"thiserror",
]
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@ -102,6 +311,15 @@ dependencies = [
"unicode-ident",
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@ -127,3 +345,97 @@ name = "unicode-ident"
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@ -3,8 +3,18 @@ name = "rlox2"
version = "0.1.0"
edition = "2021"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[[bin]]
name = "rlox"
path = "src/main.rs"
[workspace]
members = ["frontend", "interpreter"]
[dependencies.rlox2-frontend]
path = "frontend"
[dependencies.rlox2-interpreter]
path = "interpreter"
[dependencies]
phf = { version = "0.11.1", features = ["macros"] }
thiserror = "1.0"
clap = { version = "4.1.4", features = ["derive"] }

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@ -14,14 +14,18 @@ if_stmt -> "if" "(" expression ")" statement ( "else" statement )? ;
print_stmt -> "print" expression ";" ;
while_stmt -> "while" "(" expression ")" statement ;
for_stmt -> "for" "(" (declaration | expr_stmt | ";") ";" expression? ";" expression ";" ")" statement ;
declaration -> var_decl | fun_decl ;
block -> "{" statement* "}" ;
expr_Stmt -> expression ";" ;
break -> "break" ";" ;
return -> "return" expression? ";" ;
declaration -> var_decl | fun_decl | class_decl ;
var_decl -> "var" IDENTIFIER ( "=" expression )? ";"
fun_decl -> "fun" IDENTIFIER "(" parameters ")" block ;
class_decl -> "class" IDENTIFIER "{" method* "}" ;
method -> IDENTIFIER "(" parameters ")" block ;
expression -> assignment
@ -37,8 +41,8 @@ unary -> ( "!" | "-" ) unary | call ;
call -> primary ( "(" arguments? ")" )* ;
arguments -> expression ( "," expression )* ;
primary -> "(" expression ")" | IDENTIFIER | fun_expr | NUMBER | STRING | "true" | "false" | "nil" ;
primary -> "(" expression ")" | IDENTIFIER | lambda | NUMBER | STRING | "true" | "false" | "nil" ;
fun_expr -> "fun" "(" parameters ")" block ;
lambda -> "fun" "(" parameters ")" block ;
parameters -> ( IDENTIFIER ( "," IDENTIFIER )* )? ;

11
frontend/Cargo.toml Normal file
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@ -0,0 +1,11 @@
[package]
name = "rlox2-frontend"
version = "0.1.0"
edition = "2021"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies]
phf = { version = "0.11.1", features = ["macros"] }
thiserror = "1.0.38"
itertools = "0.10.5"

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@ -1,9 +1,6 @@
use phf::phf_map;
use crate::error::LexerError;
use crate::misc::CodePos;
use super::{Token, TokenType};
use super::{CodePos, LexerError, Token, TokenType};
/*====================================================================================================================*/
@ -289,7 +286,7 @@ impl Lexer {
Err(err) => {
self.errors.push(LexerError::InvalidNumberLiteral {
lexeme,
msg: format!("{err}"),
msg: err.to_string(),
code_pos: self.code_pos,
});
return None;

View file

@ -1,5 +1,3 @@
use std::fmt::{Debug, Display};
#[derive(Copy, Clone)]
pub struct CodePos {
pub line: u32,
@ -12,23 +10,14 @@ impl Default for CodePos {
}
}
impl Display for CodePos {
impl std::fmt::Display for CodePos {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "line {}, col {}", self.line, self.col)
}
}
impl Debug for CodePos {
impl std::fmt::Debug for CodePos {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "{}:{}", self.line, self.col)
}
}
/*====================================================================================================================*/
pub fn indent(s: String) -> String {
s.split('\n')
.map(|line| format!("\t{line}"))
.collect::<Vec<String>>()
.join("\n")
}

View file

@ -0,0 +1,19 @@
use thiserror::Error;
use super::CodePos;
#[derive(Error, Debug)]
pub enum LexerError {
#[error("Unexpected character '{c}' at {code_pos}.")]
UnexpectedCharacter { c: char, code_pos: CodePos },
#[error("Unterminated string literal starting at {code_pos}.")]
UnterminatedStringLiteral { code_pos: CodePos },
#[error("Unterminated block comment starting at {code_pos}.")]
UnterminatedBlockComment { code_pos: CodePos },
#[error("Invalid number literal {lexeme} at {code_pos}: {msg}")]
InvalidNumberLiteral {
lexeme: String,
msg: String,
code_pos: CodePos,
},
}

View file

@ -1,5 +1,9 @@
mod _lexer;
mod code_pos;
mod error;
mod token;
pub use _lexer::scan_tokens;
pub use code_pos::CodePos;
pub use error::LexerError;
pub use token::{Token, TokenType};

View file

@ -1,4 +1,4 @@
use crate::misc::CodePos;
use super::CodePos;
#[allow(dead_code, clippy::upper_case_acronyms)]
#[derive(Debug, Clone, PartialEq)]

2
frontend/src/lib.rs Normal file
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@ -0,0 +1,2 @@
pub mod lexer;
pub mod parser;

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@ -0,0 +1,45 @@
use thiserror::Error;
use crate::lexer::{CodePos, Token};
use super::Expr;
#[derive(Error, Debug)]
pub enum ParserError {
#[error("Token stream ended unexpectedly.")]
TokenStreamEnded,
#[error("Expected a primary expression, but found a {token} token instead at {0}.", token.code_pos)]
ExpectedPrimary { token: Token },
#[error("Missing semicolon at {code_pos}")]
MissingSemicolon { code_pos: CodePos },
#[error("Expected variable name at {0}, got {token} instead", token.code_pos)]
ExpectedVarName { token: Token },
#[error("Can't assign to {expr} at {code_pos}")]
InvalidAssignment { expr: Expr, code_pos: CodePos },
#[error("Missing closing curly brace at {code_pos}")]
MissingRightBrace { code_pos: CodePos },
#[error("Missing closing parenthesis at {code_pos}")]
MissingRightParen { code_pos: CodePos },
#[error("Missing parenthesis after if at {code_pos}")]
MissingParenAfterIf { code_pos: CodePos },
#[error("Missing parenthesis after while at {code_pos}")]
MissingParenAfterWhile { code_pos: CodePos },
#[error("Missing parenthesis after for at {code_pos}")]
MissingParenAfterFor { code_pos: CodePos },
#[error("Call at {code_pos} has too many arguments")]
TooManyArguments { code_pos: CodePos },
#[error("{msg} at {code_pos}")]
MissingIdentifier { msg: String, code_pos: CodePos },
#[error("Missing arguments to function declaration at {code_pos}")]
MissingFunctionArgs { code_pos: CodePos },
#[error("Missing body to function declaration at {code_pos}")]
MissingFunctionBody { code_pos: CodePos },
#[error("Function declaration at {code_pos} has too many parameters")]
TooManyParams { code_pos: CodePos },
#[error("Return statement outside of function definition")]
InvalidReturn { code_pos: CodePos },
#[error("Break statement outside of loop")]
InvalidBreak { code_pos: CodePos },
#[error("Missing class body at {code_pos}")]
MissingClassBody { code_pos: CodePos },
}

View file

@ -1,6 +1,8 @@
use std::fmt::Display;
use std::rc::Rc;
use itertools::Itertools;
use super::Stmt;
#[derive(Debug, Clone)]
@ -28,8 +30,15 @@ pub enum Expr {
Variable {
name: String,
},
Assignment {
LocalVariable {
name: String,
level: usize,
},
GlobalVariable {
name: String,
},
Assignment {
target: Box<Expr>,
value: Box<Expr>,
},
Call {
@ -39,6 +48,7 @@ pub enum Expr {
Function {
name: String,
param_names: Vec<String>,
closure_vars: Vec<(String, usize)>,
body: Box<Stmt>,
},
}
@ -89,10 +99,10 @@ impl Expr {
Expr::Grouping { expr }
}
pub fn assignment(name: impl Into<String>, value: Expr) -> Self {
let name = name.into();
pub fn assignment(target: Expr, value: Expr) -> Self {
let target = Box::new(target);
let value = Box::new(value);
Expr::Assignment { name, value }
Expr::Assignment { target, value }
}
pub fn call(callee: Expr, args: Vec<Expr>) -> Self {
@ -105,6 +115,7 @@ impl Expr {
Self::Function {
name,
param_names,
closure_vars: Vec::new(),
body,
}
}
@ -120,26 +131,28 @@ impl Display for Expr {
write!(f, "({op} {left} {right})")
}
Expr::Grouping { expr } => write!(f, "(group {expr})"),
Expr::Variable { name } => write!(f, "{name}"),
Expr::Assignment { name, value } => write!(f, "{name} = {value}"),
Expr::Call { callee, args } => write!(
f,
"({callee} {})",
args.iter()
.map(|arg| format!("{arg}"))
.collect::<Vec<String>>()
.join(" ")
),
Expr::Variable { name } => write!(f, "(var {name})"),
Expr::LocalVariable { name, level } => write!(f, "(var {name} local({level}))"),
Expr::GlobalVariable { name } => write!(f, "(var {name} global)"),
Expr::Assignment { target, value } => write!(f, "{target} = {value}"),
Expr::Call { callee, args } => write!(f, "({callee} {})", args.iter().map(|arg| arg.to_string()).join(" ")),
Expr::Function {
name,
param_names,
closure_vars,
body,
} => {
if !closure_vars.is_empty() {
let closure_fmt = closure_vars.iter().map(|(name, _level)| name).join(", ");
write!(f, "fun [{closure_fmt}] {name}({}) {body}", param_names.join(", "))
} else {
write!(f, "fun {name}({}) {body}", param_names.join(", "))
}
}
}
}
}
/*====================================================================================================================*/

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@ -0,0 +1,5 @@
use itertools::Itertools;
pub fn indent(s: String) -> String {
s.split('\n').map(|line| format!("\t{line}")).join("\n")
}

View file

@ -1,7 +1,10 @@
mod _parser;
mod error;
mod expr;
mod misc;
mod parse;
mod stmt;
pub use _parser::parse_tokens;
pub use error::ParserError;
pub use expr::{BinaryOp, Expr, Literal, LogicalOp, UnaryOp};
pub use parse::parse_tokens;
pub use stmt::Stmt;

View file

@ -1,11 +1,10 @@
use std::vec::IntoIter;
use crate::error::ParserError;
use crate::lexer::{Token, TokenType};
use crate::parser::expr::BinaryOp;
use super::expr::{Expr, UnaryOp};
use super::{LogicalOp, Stmt};
use super::{LogicalOp, ParserError, Stmt};
/*====================================================================================================================*/
@ -62,6 +61,9 @@ struct Parser {
token_iter: TokenIter,
parse_errors: Vec<ParserError>,
is_in_function: bool,
is_in_loop: bool,
}
impl Parser {
@ -69,6 +71,8 @@ impl Parser {
Parser {
token_iter: TokenIter::new(tokens),
parse_errors: Vec::new(),
is_in_function: false,
is_in_loop: false,
}
}
@ -142,20 +146,29 @@ impl Parser {
TokenType::While => self.while_statement(),
TokenType::For => self.for_statement(),
TokenType::Var => self.var_declaration(),
TokenType::Class => self.class_declaration(),
TokenType::Fun => self.fun_declaration(),
TokenType::LeftBrace => self.block(),
TokenType::Break => {
let code_pos = self.peek_token().code_pos;
assert_eq!(self.next_token().token_type, TokenType::Break);
self.semicolon()?;
if !self.is_in_loop {
return Err(ParserError::InvalidBreak { code_pos });
}
Ok(Stmt::Break)
}
TokenType::Return => {
let code_pos = self.peek_token().code_pos;
assert_eq!(self.next_token().token_type, TokenType::Return);
let expr = match self.peek_token().token_type {
TokenType::Semicolon => Expr::nil(),
_ => self.expression()?,
};
self.semicolon()?;
if !self.is_in_function {
return Err(ParserError::InvalidReturn { code_pos });
}
Ok(Stmt::return_stmt(expr))
}
_ => self.expression_statement(),
@ -202,7 +215,17 @@ impl Parser {
code_pos: token.code_pos,
})?;
let body = self.statement()?;
let is_in_loop = std::mem::replace(&mut self.is_in_loop, true);
let body = match self.statement() {
Ok(body) => body,
Err(err) => {
self.is_in_loop = is_in_loop;
return Err(err);
}
};
self.is_in_loop = is_in_loop;
Ok(Stmt::while_stmt(condition, body))
}
@ -239,7 +262,17 @@ impl Parser {
code_pos: token.code_pos,
})?;
let mut body = self.statement()?;
let is_in_loop = std::mem::replace(&mut self.is_in_loop, true);
let mut body = match self.statement() {
Ok(body) => body,
Err(err) => {
self.is_in_loop = is_in_loop;
return Err(err);
}
};
self.is_in_loop = is_in_loop;
if let Some(increment) = increment {
body = Stmt::Block {
@ -295,6 +328,38 @@ impl Parser {
Ok(Stmt::var_decl(name, initializer))
}
fn class_declaration(&mut self) -> ParserResult<Stmt> {
assert_eq!(self.next_token().token_type, TokenType::Class);
let name = self.identifier("Missing class name")?;
self.consume_token(TokenType::LeftBrace, |token| ParserError::MissingClassBody {
code_pos: token.code_pos,
})?;
let mut methods = Vec::new();
while self.peek_token().token_type != TokenType::RightBrace {
let method_name = self.identifier("Expected method name").map_err(|err| {
if self.peek_token().token_type == TokenType::EOF {
ParserError::MissingRightBrace {
code_pos: self.peek_token().code_pos,
}
} else {
err
}
})?;
let method = self.fun_params_and_body(method_name)?;
methods.push(method);
}
assert_eq!(self.next_token().token_type, TokenType::RightBrace);
Ok(Stmt::Class { name, methods })
}
fn fun_declaration(&mut self) -> ParserResult<Stmt> {
assert_eq!(self.next_token().token_type, TokenType::Fun);
@ -331,7 +396,20 @@ impl Parser {
});
}
let body = self.block()?;
let is_in_function = std::mem::replace(&mut self.is_in_function, true);
let is_in_loop = std::mem::replace(&mut self.is_in_loop, false);
let body = match self.block() {
Ok(body) => body,
Err(err) => {
self.is_in_function = is_in_function;
self.is_in_loop = is_in_loop;
return Err(err);
}
};
self.is_in_function = is_in_function;
self.is_in_loop = is_in_loop;
let name = name.into();
Ok(Expr::function(name, param_names, body))
@ -415,7 +493,7 @@ impl Parser {
let value = self.assignment()?;
match expr {
Expr::Variable { name } => Ok(Expr::assignment(name, value)),
Expr::Variable { name } => Ok(Expr::assignment(Expr::Variable { name }, value)),
_ => Err(ParserError::InvalidAssignment { expr, code_pos }),
}
}

View file

@ -1,7 +1,6 @@
use std::fmt::Display;
use crate::misc::indent;
use super::misc::indent;
use super::Expr;
#[derive(Debug, Clone)]
@ -25,6 +24,10 @@ pub enum Stmt {
Block {
statements: Vec<Stmt>,
},
Class {
name: String,
methods: Vec<Expr>,
},
ExprStmt {
expr: Box<Expr>,
},
@ -92,13 +95,13 @@ impl Display for Stmt {
writeln!(f, "if {condition}")?;
match then_branch.as_ref() {
Stmt::Block { .. } => write!(f, "{then_branch}")?,
_ => write!(f, "{}", indent(format!("{then_branch}")))?,
_ => write!(f, "{}", indent(then_branch.to_string()))?,
}
if let Some(else_branch) = else_branch {
writeln!(f, "\nelse")?;
match else_branch.as_ref() {
Stmt::Block { .. } => write!(f, "{else_branch}")?,
_ => write!(f, "{}", indent(format!("{else_branch}")))?,
_ => write!(f, "{}", indent(else_branch.to_string()))?,
}
}
Ok(())
@ -107,7 +110,7 @@ impl Display for Stmt {
writeln!(f, "{condition}")?;
match body.as_ref() {
Stmt::Block { .. } => write!(f, "{body}")?,
_ => write!(f, "{}", indent(format!("{body}")))?,
_ => write!(f, "{}", indent(body.to_string()))?,
}
Ok(())
}
@ -115,7 +118,14 @@ impl Display for Stmt {
Stmt::Block { statements } => {
writeln!(f, "{{")?;
for statement in statements {
write!(f, "{}", indent(format!("{statement}")))?;
writeln!(f, "{}", indent(statement.to_string()))?;
}
write!(f, "}}")
}
Stmt::Class { name, methods } => {
writeln!(f, "class {name} {{")?;
for method in methods {
writeln!(f, "{method}")?;
}
write!(f, "}}")
}

13
interpreter/Cargo.toml Normal file
View file

@ -0,0 +1,13 @@
[package]
name = "rlox2-interpreter"
version = "0.1.0"
edition = "2021"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies.rlox2-frontend]
path = "../frontend"
[dependencies]
thiserror = "1.0.38"
itertools = "0.10.5"

19
interpreter/src/class.rs Normal file
View file

@ -0,0 +1,19 @@
use std::fmt::Display;
#[derive(Debug)]
pub struct LoxClass {
name: String,
}
impl LoxClass {
pub fn new(name: impl Into<String>) -> Self {
let name = name.into();
LoxClass { name }
}
}
impl Display for LoxClass {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "<class {}>", self.name)
}
}

View file

@ -0,0 +1,209 @@
use std::collections::HashMap;
use std::fmt::Display;
use std::io::{Read, Write};
use crate::error::RuntimeError;
use super::value::HeapedValue;
use super::{Runtime, Value};
pub type Scope = HashMap<String, HeapedValue>;
#[derive(Debug)]
pub struct Environment<'a> {
local_scopes: Vec<Scope>,
runtime: &'a mut Runtime,
}
impl<'a> Environment<'a> {
pub fn new(runtime: &'a mut Runtime) -> Self {
Environment {
// globals: HashMap::new(),
// frames: vec![Frame::new_global()],
local_scopes: Vec::new(),
runtime,
}
}
pub fn globals(&self) -> &HashMap<String, Value> {
self.runtime.globals()
}
pub fn enter_scope(&mut self) {
// self.current_frame_mut().enter_scope();
self.local_scopes.push(Scope::new());
}
pub fn push_scope(&mut self, scope: Scope) {
self.local_scopes.push(scope);
}
pub fn exit_scope(&mut self) {
// self.current_frame_mut().exit_scope();
self.local_scopes.pop().expect("Tried to pop global scope");
}
pub fn get_global(&self, name: &str) -> Result<Value, RuntimeError> {
self.runtime.get_global(name)
}
pub fn get_local(&self, name: &str, level: usize) -> Result<Value, RuntimeError> {
if let Some(scope) = self.local_scopes.iter().rev().nth(level) {
if let Some(heap_value) = scope.get(name) {
return Ok(heap_value.get_clone());
}
}
// DEBUG
println!("Name {name} not defined at level {level}");
println!("{self}");
Err(RuntimeError::NameNotDefined { name: name.to_owned() })
// self.runtime.get_global(name)
}
pub fn define(&mut self, name: impl Into<String>, value: Value) {
if let Some(scope) = self.local_scopes.last_mut() {
let name = name.into();
scope.insert(name, HeapedValue::new(value));
} else {
self.runtime.define_global(name, value)
}
}
pub fn assign_global(&mut self, name: &str, value: Value) -> Result<(), RuntimeError> {
self.runtime.assign_global(name, value)
}
pub fn assign(&mut self, name: &str, value: Value, level: usize) -> Result<(), RuntimeError> {
if let Some(scope) = self.local_scopes.iter_mut().rev().nth(level) {
if let Some(heap_value) = scope.get_mut(name) {
heap_value.replace(value);
return Ok(());
}
}
Err(RuntimeError::NameNotDefined { name: name.to_owned() })
// self.runtime.assign_global(name, value)
}
/* pub fn push_frame(&mut self, base_scope: Scope) {
self.frames.push(Frame::new(base_scope));
}
pub fn pop_frame(&mut self) {
self.frames.pop().expect("Tried to pop global frame");
} */
pub fn collect_closure(&self, closure_vars: &[(String, usize)]) -> Scope {
let mut closure_scope = Scope::new();
for (name, level) in closure_vars {
let heap_value = self
.local_scopes
.iter()
.rev()
.nth(*level)
.unwrap()
.get(name)
.unwrap()
.clone();
let name = name.to_owned();
closure_scope.insert(name, heap_value);
}
closure_scope
}
}
impl Display for Environment<'_> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "{}", self.runtime)?;
for (level, scope) in self.local_scopes.iter().enumerate() {
write!(f, "\nScope {level}:")?;
for (name, value) in scope.iter() {
write!(f, "\n\t{name} = {value}")?;
}
}
Ok(())
}
}
impl Read for Environment<'_> {
fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
self.runtime.read(buf)
}
}
impl Write for Environment<'_> {
fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
self.runtime.write(buf)
}
fn flush(&mut self) -> std::io::Result<()> {
self.runtime.flush()
}
}
/*====================================================================================================================*/
/* struct Frame {
scopes: Vec<Scope>,
}
impl Frame {
fn new(base_scope: Scope) -> Self {
Frame {
scopes: vec![base_scope],
}
}
fn new_global() -> Self {
Frame { scopes: Vec::new() }
}
fn enter_scope(&mut self) {
self.scopes.push(Scope::new());
}
fn exit_scope(&mut self) {
self.scopes.pop().expect("Tried to exit scope, but no scope to exit");
}
fn get(&self, name: &str) -> Option<Value> {
for scope in self.scopes.iter().rev() {
if let Some(heap_value) = scope.get(name) {
return Some(heap_value.get_clone());
}
}
None
}
fn try_define(&mut self, name: impl Into<String> + Borrow<str>, value: Value) -> Result<(), Value> {
if let Some(scope) = self.scopes.last_mut() {
scope.insert(name.into(), HeapValue::new(value));
Ok(())
} else {
Err(value)
}
}
fn try_assign(&mut self, name: &str, value: Value) -> Result<(), Value> {
for scope in self.scopes.iter_mut().rev() {
if let Some(heap_value) = scope.get_mut(name) {
heap_value.replace(value);
return Ok(());
}
}
Err(value)
}
} */

85
interpreter/src/error.rs Normal file
View file

@ -0,0 +1,85 @@
use itertools::Itertools;
use rlox2_frontend::lexer::LexerError;
use rlox2_frontend::parser::{BinaryOp, ParserError, UnaryOp};
use thiserror::Error;
use crate::ResolverError;
use crate::Value;
#[derive(Error, Debug)]
pub enum RuntimeError {
#[error("Unary operator {op} had invalid argument {arg}")]
UnaryOpInvalidArgument { op: UnaryOp, arg: Value },
#[error("Binary operator {op} had invalid arguments {left} and {right}")]
BinaryOpInvalidArguments { left: Value, op: BinaryOp, right: Value },
#[error("Division by zero")]
DivisionByZero,
#[error("Name {name} is not defined")]
NameNotDefined { name: String },
#[error("Global {name} is not defined")]
GlobalNotDefined { name: String },
#[error("{callee} is not callable")]
NotCallable { callee: Value },
#[error("{name}() takes {arity} args, but {given} were given.")]
WrongArity { name: String, arity: usize, given: usize },
#[error("Extern function call to {name} failed: {msg}")]
ExtFunCallFailed { name: String, msg: String },
#[error("Uncaught break statement")]
Break,
#[error("Uncaught return statement")]
Return { value: Value },
#[error("Exit with exit code {exit_code}")]
Exit { exit_code: i32 },
}
#[derive(Error, Debug)]
#[allow(clippy::enum_variant_names)]
pub enum LoxError {
#[error("{0}", format_multiple_errors(inner))]
LexerError { inner: Vec<LexerError> },
#[error("{0}", format_multiple_errors(inner))]
ParserError { inner: Vec<ParserError> },
#[error("{inner}")]
ResolverError { inner: ResolverError },
#[error("{inner}")]
RuntimeError { inner: RuntimeError },
#[error("Called exit() with exit code {exit_code}")]
Exit { exit_code: i32 },
}
fn format_multiple_errors(errs: &Vec<impl std::error::Error>) -> String {
let msg = if errs.len() == 1 {
errs[0].to_string()
} else {
errs.iter().map(|err| err.to_string()).join("\n")
};
msg
}
impl From<Vec<LexerError>> for LoxError {
fn from(lexer_errs: Vec<LexerError>) -> Self {
LoxError::LexerError { inner: lexer_errs }
}
}
impl From<Vec<ParserError>> for LoxError {
fn from(parser_errs: Vec<ParserError>) -> Self {
LoxError::ParserError { inner: parser_errs }
}
}
impl From<ResolverError> for LoxError {
fn from(resolver_err: ResolverError) -> Self {
LoxError::ResolverError { inner: resolver_err }
}
}
impl From<RuntimeError> for LoxError {
fn from(runtime_err: RuntimeError) -> Self {
match runtime_err {
RuntimeError::Exit { exit_code } => LoxError::Exit { exit_code },
_ => LoxError::RuntimeError { inner: runtime_err },
}
}
}

View file

@ -1,10 +1,10 @@
use std::fmt::{Debug, Display};
use crate::parser::Stmt;
use rlox2_frontend::parser::Stmt;
use super::environment::{Environment, Scope};
use super::interpret::EvalResult;
use super::Value;
use super::{Runtime, Value};
#[derive(Debug, Clone)]
pub struct LoxFunction {
@ -15,12 +15,12 @@ pub struct LoxFunction {
}
impl LoxFunction {
pub fn new(name: impl Into<String>, param_names: Vec<String>, body: Stmt) -> Self {
pub fn new(name: impl Into<String>, closure: Scope, param_names: Vec<String>, body: Stmt) -> Self {
let name = name.into();
let body = Box::new(body);
LoxFunction {
name,
closure: Scope::new(),
closure,
param_names,
body,
}
@ -71,10 +71,10 @@ impl LoxExternFunction {
LoxExternFunction { name, closure }
}
pub fn register(self, env: &mut Environment) {
pub fn register(self, env: &mut Runtime) {
let name = self.name.clone();
let fun = Value::extern_function(self);
env.define(name, fun);
env.define_global(name, fun);
}
pub fn call(&self, args: Vec<Value>, env: &mut Environment) -> EvalResult<Value> {

View file

@ -1,26 +1,32 @@
use std::rc::Rc;
use rlox2_frontend::parser::{BinaryOp, Expr, Literal, LogicalOp, Stmt, UnaryOp};
use crate::error::RuntimeError;
use crate::parser::{BinaryOp, Expr, Literal, LogicalOp, Stmt, UnaryOp};
use crate::LoxClass;
use super::environment::Environment;
use super::{LoxFunction, Value};
use super::{LoxFunction, Runtime, Value};
pub type EvalResult<T> = Result<T, RuntimeError>;
/*====================================================================================================================*/
pub fn execute(statement: Stmt, env: &mut Environment) -> Result<(), RuntimeError> {
statement.execute(env)
pub fn execute(statement: Stmt, runtime: &mut Runtime) -> Result<(), RuntimeError> {
let mut env = Environment::new(runtime);
statement.eval(&mut env)?;
Ok(())
}
/*====================================================================================================================*/
/* trait Eval {
fn eval(self, env: &mut Environment) -> EvalResult;
} */
trait Eval {
fn eval(&self, env: &mut Environment) -> EvalResult<Value>;
}
impl Literal {
impl Eval for Literal {
fn eval(&self, env: &mut Environment) -> EvalResult<Value> {
let _ = env;
match self {
@ -32,7 +38,7 @@ impl Literal {
}
}
impl Expr {
impl Eval for Expr {
fn eval(&self, env: &mut Environment) -> EvalResult<Value> {
match self {
Expr::Literal { literal } => literal.eval(env),
@ -104,10 +110,17 @@ impl Expr {
Ok(right)
}
Expr::Grouping { expr } => expr.eval(env),
Expr::Variable { name } => env.get(name),
Expr::Assignment { name, value } => {
Expr::Variable { name } => panic!("Unresolved variable {name}"),
Expr::LocalVariable { name, level } => env.get_local(name, *level),
Expr::GlobalVariable { name } => env.get_global(name),
Expr::Assignment { target, value } => {
let value = value.eval(env)?;
env.assign(name, value.clone())?;
match target.as_ref() {
Expr::LocalVariable { name, level } => env.assign(name, value.clone(), *level)?,
Expr::GlobalVariable { name } => env.assign_global(name, value.clone())?,
_ => panic!("Invalid assigment target {target}"),
}
Ok(value)
}
Expr::Call { callee, args } => {
@ -126,9 +139,11 @@ impl Expr {
Expr::Function {
name,
param_names,
closure_vars,
body,
} => Ok(Value::function(LoxFunction::new(
name,
env.collect_closure(closure_vars),
param_names.clone(),
body.as_ref().clone(),
))),
@ -136,8 +151,8 @@ impl Expr {
}
}
impl Stmt {
fn execute(&self, env: &mut Environment) -> EvalResult<()> {
impl Eval for Stmt {
fn eval(&self, env: &mut Environment) -> EvalResult<Value> {
match self {
Stmt::Print { expr } => {
match expr.eval(env)? {
@ -145,8 +160,6 @@ impl Stmt {
Value::String(s) => println!("{s}"),
val => println!("{val}"),
}
Ok(())
}
Stmt::IfStmt {
condition,
@ -155,49 +168,54 @@ impl Stmt {
} => {
let condition = condition.eval(env)?;
if condition.is_truthy() {
then_branch.execute(env)
then_branch.eval(env)?;
} else if let Some(else_branch) = else_branch {
else_branch.execute(env)
} else {
Ok(())
else_branch.eval(env)?;
}
}
Stmt::While { condition, body } => {
while condition.eval(env)?.is_truthy() {
match body.execute(env) {
match body.eval(env) {
Ok(_) => {}
Err(RuntimeError::Break) => break,
Err(err) => return Err(err),
}
}
Ok(())
}
Stmt::VarDecl { name, initializer } => {
let initializer = initializer.eval(env)?;
env.define(name.as_ref(), initializer);
Ok(())
env.define(name, initializer);
}
Stmt::Block { statements } => {
env.enter_scope();
for statement in statements {
// on error the current frame gets destroyed anyways, so no need to exit scope
statement.execute(env)?;
if let Err(err) = statement.eval(env) {
env.exit_scope();
return Err(err);
}
}
env.exit_scope();
Ok(())
}
Stmt::Class { name, methods: _ } => {
env.define(name, Value::Nil);
let class = Value::class(LoxClass::new(name));
env.assign(name, class, 0)?;
}
Stmt::ExprStmt { expr } => {
// expr.eval(env)?;
// Ok(Value::Nil)
expr.eval(env)?;
Ok(())
}
Stmt::Break => Err(RuntimeError::Break),
Stmt::Break => return Err(RuntimeError::Break),
Stmt::Return { expr } => {
let value = expr.eval(env)?;
Err(RuntimeError::Return { value })
return Err(RuntimeError::Return { value });
}
}
Ok(Value::Nil)
}
}
@ -213,20 +231,20 @@ impl LoxFunction {
});
}
env.push_frame(self.closure().clone());
env.push_scope(self.closure().clone());
for (name, value) in std::iter::zip(self.param_names(), args) {
env.define(name.as_ref(), value);
env.define(name, value);
}
let ret_val = match self.body().execute(env) {
Ok(()) => Value::Nil,
Err(RuntimeError::Return { value }) => value,
Err(err) => return Err(err),
let ret_val = match self.body().eval(env) {
Ok(_) => Ok(Value::Nil),
Err(RuntimeError::Return { value }) => Ok(value),
Err(err) => Err(err),
};
env.pop_frame();
env.exit_scope();
Ok(ret_val)
ret_val
}
}

18
interpreter/src/lib.rs Normal file
View file

@ -0,0 +1,18 @@
mod class;
mod environment;
mod error;
mod function;
mod interpret;
mod lox_std;
mod resolver;
mod run;
mod runtime;
mod value;
pub use class::LoxClass;
pub use error::{LoxError, RuntimeError};
pub use function::LoxFunction;
pub use resolver::{resolve, ResolverError};
pub use run::{run_file, run_repl};
pub use runtime::Runtime;
pub use value::Value;

View file

@ -1,15 +1,14 @@
use crate::error::RuntimeError;
use super::environment::Environment;
use super::function::{ExternFunClosure, LoxExternFunction};
use super::value::HeapValue;
use super::Value;
use super::{Runtime, Value};
pub fn init_std(env: &mut Environment) {
input().register(env);
pub fn init_std(env: &mut Runtime) {
clock().register(env);
print_globals().register(env);
exit().register(env);
input().register(env);
print_env().register(env);
print_globals().register(env);
}
fn input() -> LoxExternFunction {
@ -58,7 +57,7 @@ fn clock() -> LoxExternFunction {
fn print_globals() -> LoxExternFunction {
let closure: ExternFunClosure = |args, env| match *args {
[] => {
let mut globals: Vec<(&String, &HeapValue)> = env.globals().iter().collect();
let mut globals: Vec<(&String, &Value)> = env.globals().iter().collect();
globals.sort_by_key(|&(name, _value)| name);
@ -77,6 +76,21 @@ fn print_globals() -> LoxExternFunction {
LoxExternFunction::new("print_globals", closure)
}
fn print_env() -> LoxExternFunction {
let closure: ExternFunClosure = |args, env| match *args {
[] => {
println!("{env}");
Ok(Value::Nil)
}
_ => Err(RuntimeError::ExtFunCallFailed {
name: "print_env".to_owned(),
msg: "print_env() takes no arguments".to_owned(),
}),
};
LoxExternFunction::new("print_env", closure)
}
fn exit() -> LoxExternFunction {
let closure: ExternFunClosure = |args, _env| {
match &*args {

View file

@ -0,0 +1,11 @@
use thiserror::Error;
#[derive(Error, Debug)]
pub enum ResolverError {
#[error("Can't read variable {name} in its own initializer.")]
VarInOwnInitializer { name: String },
#[error("Could not resolve variable {name}")]
UnresolvableVariable { name: String },
#[error("Return outside of function definition")]
ReturnOutsideFunction,
}

View file

@ -0,0 +1,5 @@
mod error;
mod resolve;
pub use error::ResolverError;
pub use resolve::resolve;

View file

@ -0,0 +1,276 @@
use std::collections::HashMap;
use rlox2_frontend::parser::{Expr, Stmt};
use crate::Runtime;
use crate::{LoxError, ResolverError};
/*====================================================================================================================*/
type ResolverScope = HashMap<String, ResolveStatus>;
type ResolverFrame = Vec<ResolverScope>;
/*====================================================================================================================*/
#[derive(Debug, Clone, Copy)]
enum ResolveStatus {
Declared,
Defined,
}
/*====================================================================================================================*/
pub fn resolve(statement: &mut Stmt, runtime: &mut Runtime) -> Result<(), LoxError> {
let global_names = runtime.globals().keys().cloned();
let mut resolver = Resolver::new(global_names);
resolver.resolve_stmt(statement)?;
Ok(())
}
#[derive(Debug)]
struct Resolver {
global_scope: ResolverScope,
// local_scopes: Vec<ResolverScope>,
frames: Vec<ResolverFrame>,
closure_vars: HashMap<String, usize>,
}
impl Resolver {
fn new(global_names: impl Iterator<Item = String>) -> Self {
let mut global_scope = ResolverScope::new();
for name in global_names {
global_scope.insert(name, ResolveStatus::Defined);
}
Resolver {
global_scope,
frames: vec![ResolverFrame::new()],
closure_vars: HashMap::new(),
}
}
fn local_scopes(&self) -> &ResolverFrame {
self.frames.last().unwrap()
}
fn local_scopes_mut(&mut self) -> &mut ResolverFrame {
self.frames.last_mut().unwrap()
}
fn enter_scope(&mut self) {
self.local_scopes_mut().push(ResolverScope::new());
}
fn exit_scope(&mut self) {
self.local_scopes_mut()
.pop()
.expect("Tried to pop from empty ResolverFrame");
}
fn push_frame(&mut self) {
self.frames.push(vec![ResolverScope::new()]);
}
fn pop_frame(&mut self) {
self.frames.pop().expect("Tried to pop non-existant ResolverFrame");
}
fn declare(&mut self, name: &str) {
let name = name.to_owned();
if let Some(local_scope) = self.local_scopes_mut().last_mut() {
local_scope.insert(name, ResolveStatus::Declared);
} else {
self.global_scope.insert(name, ResolveStatus::Declared);
}
}
fn define(&mut self, name: &str) {
let name = name.to_owned();
if let Some(local_scope) = self.local_scopes_mut().last_mut() {
local_scope.insert(name, ResolveStatus::Defined);
} else {
self.global_scope.insert(name, ResolveStatus::Declared);
}
}
fn check(&self, name: &str) -> Option<ResolveStatus> {
if let Some(local_scope) = self.local_scopes().last() {
local_scope.get(name).cloned()
} else {
self.global_scope.get(name).cloned()
}
}
fn resolve_var(&mut self, name: &str) -> Result<Expr, ResolverError> {
let name = name.to_owned();
let mut level = 0;
for scope in self.local_scopes().iter().rev() {
if scope.contains_key(&name) {
return Ok(Expr::LocalVariable { name, level });
}
// DEBUG
level += 1;
}
for frame in self.frames.iter().rev().skip(1) {
for scope in frame.iter().rev() {
if scope.contains_key(&name) {
if !self.closure_vars.contains_key(&name) {
// the level at which the closed-over variable will be collected from
// from the perspective of the parameter/closure scope i.e. the outmost of the function
self.closure_vars
.insert(name.clone(), level - self.local_scopes().len());
}
return Ok(Expr::LocalVariable {
name,
// distance from actual variable refernce to parameter/closure scope
level: self.local_scopes().len() - 1,
});
}
level += 1;
}
}
if self.global_scope.contains_key(&name) {
return Ok(Expr::GlobalVariable { name });
}
Err(ResolverError::UnresolvableVariable { name })
}
fn resolve_stmt(&mut self, stmt: &mut Stmt) -> Result<(), ResolverError> {
match stmt {
Stmt::Print { expr } => self.resolve_expr(expr),
Stmt::IfStmt {
condition,
then_branch,
else_branch,
} => {
self.resolve_expr(condition)?;
self.resolve_stmt(then_branch)?;
if let Some(else_branch) = else_branch {
self.resolve_stmt(else_branch)?;
}
Ok(())
}
Stmt::While { condition, body } => {
self.resolve_expr(condition)?;
self.resolve_stmt(body)?;
Ok(())
}
Stmt::VarDecl { name, initializer } => {
self.declare(name);
self.resolve_expr(initializer)?;
self.define(name);
Ok(())
}
Stmt::Block { statements } => {
self.enter_scope();
for statement in statements.iter_mut() {
self.resolve_stmt(statement)?;
}
self.exit_scope();
Ok(())
}
Stmt::Class { name, methods: _ } => {
self.declare(name);
self.define(name);
Ok(())
}
Stmt::ExprStmt { expr } => self.resolve_expr(expr),
Stmt::Break => Ok(()),
Stmt::Return { expr } => self.resolve_expr(expr),
}
}
fn resolve_expr(&mut self, expr: &mut Expr) -> Result<(), ResolverError> {
match expr {
Expr::Literal { literal: _ } => Ok(()),
Expr::Unary { op: _, expr } => self.resolve_expr(expr),
Expr::Binary { left, op: _, right } => {
self.resolve_expr(left)?;
self.resolve_expr(right)?;
Ok(())
}
Expr::Logical { left, op: _, right } => {
self.resolve_expr(left)?;
self.resolve_expr(right)?;
Ok(())
}
Expr::Grouping { expr } => self.resolve_expr(expr),
Expr::Variable { name } => {
if let Some(ResolveStatus::Declared) = self.check(name) {
let name = name.clone();
return Err(ResolverError::VarInOwnInitializer { name });
}
*expr = self.resolve_var(name)?;
Ok(())
}
Expr::LocalVariable { name, level: _ } => {
panic!("Tried to resolve variable {name} twice")
}
Expr::GlobalVariable { name } => {
panic!("Tried to resolve variable {name} twice")
}
Expr::Assignment { target, value } => {
self.resolve_expr(value)?;
let target = target.as_mut();
if let Expr::Variable { name } = target {
*target = self.resolve_var(name)?;
} else {
panic!("Invalid assignment target {target}");
}
Ok(())
}
Expr::Call { callee, args } => {
self.resolve_expr(callee)?;
for arg in args.iter_mut() {
self.resolve_expr(arg)?;
}
Ok(())
}
Expr::Function {
name,
param_names,
closure_vars,
body,
} => {
let old_closure_names = std::mem::take(&mut self.closure_vars);
self.push_frame();
self.declare(name);
self.define(name);
for param_name in param_names {
self.declare(param_name);
self.define(param_name);
}
self.resolve_stmt(body)?;
self.pop_frame();
let closure_names = std::mem::replace(&mut self.closure_vars, old_closure_names);
for closure_var in closure_names {
closure_vars.push(closure_var);
}
Ok(())
}
}
}
}

View file

@ -1,28 +1,17 @@
use std::io::Write;
use rlox2_frontend::lexer::{scan_tokens, Token};
use rlox2_frontend::parser::parse_tokens;
use crate::error::LoxError;
use crate::interpreter::interpret::execute;
use crate::lexer::{scan_tokens, Token};
use crate::parser::parse_tokens;
use crate::interpret::execute;
use crate::resolver::resolve;
use super::environment::Environment;
use super::Runtime;
pub fn interpreter_main() {
let args: Vec<String> = std::env::args().collect();
match args.len() {
1 => run_repl(),
2 => run_file(&args[1]),
_ => {
eprintln!("Usage: rlox [script]");
std::process::exit(64);
}
}
}
fn run_file(script_path: &str) {
pub fn run_file(runtime: &mut Runtime, script_path: &str) {
let source_code = std::fs::read_to_string(script_path).unwrap_or_else(|err| {
eprintln!("Reading script file {} failed: {}", script_path, err);
eprintln!("Reading script file {script_path} failed: {err}");
std::process::exit(66);
});
@ -31,14 +20,14 @@ fn run_file(script_path: &str) {
std::process::exit(65);
} */
let mut env = Environment::new();
match run(&source_code, &mut env) {
Ok(()) => std::process::exit(0),
match run(&source_code, runtime) {
Ok(()) => {}
Err(err) => {
eprintln!("{err}");
match err {
LoxError::LexerError { .. } | LoxError::ParserError { .. } => std::process::exit(65),
LoxError::LexerError { .. } | LoxError::ParserError { .. } | LoxError::ResolverError { .. } => {
std::process::exit(65)
}
LoxError::RuntimeError { .. } => std::process::exit(70),
LoxError::Exit { exit_code } => std::process::exit(exit_code),
}
@ -46,11 +35,9 @@ fn run_file(script_path: &str) {
}
}
fn run_repl() {
pub fn run_repl(runtime: &mut Runtime) {
let stdin = std::io::stdin();
let mut env = Environment::new();
loop {
let mut input_buf = String::new();
@ -59,7 +46,7 @@ fn run_repl() {
'inner: loop {
stdin.read_line(&mut input_buf).unwrap_or_else(|err| {
eprintln!("Could not read from stdin: {}", err);
eprintln!("Could not read from stdin: {err}");
std::process::exit(66);
});
@ -78,6 +65,11 @@ fn run_repl() {
}
print!("< ");
// let indentation = " ".repeat((num_open_braces + num_open_brackets + num_open_parens) as usize);
// print!("{indentation}");
std::io::stdout().flush().unwrap();
}
@ -87,21 +79,20 @@ fn run_repl() {
std::process::exit(0);
}
match run(input_buf, &mut env) {
match run(input_buf, runtime) {
Ok(()) => {}
Err(LoxError::Exit { exit_code }) => std::process::exit(exit_code),
Err(err) => eprintln!("{}", err),
Err(err) => eprintln!("{err}"),
}
}
}
fn run(code_string: &str, env: &mut Environment) -> Result<(), LoxError> {
fn run(code_string: &str, runtime: &mut Runtime) -> Result<(), LoxError> {
let tokens: Vec<Token> = scan_tokens(code_string)?;
/* let token_str = tokens
.iter()
.map(|token| format!("{token}"))
.collect::<Vec<String>>()
.map(|token| token.to_string())
.join(" ");
println!("{token_str}"); */
@ -112,16 +103,14 @@ fn run(code_string: &str, env: &mut Environment) -> Result<(), LoxError> {
println!("{statement}");
} */
// let mut result = Value::Nil;
for statement in statements {
execute(statement, env)?;
}
/* match result {
Value::Nil => {}
result => println!("{result}"),
/* for statement in statements.iter() {
println!("{statement}");
} */
for mut statement in statements {
resolve(&mut statement, runtime)?;
execute(statement, runtime)?;
}
Ok(())
}

101
interpreter/src/runtime.rs Normal file
View file

@ -0,0 +1,101 @@
use std::collections::HashMap;
use std::fmt::Display;
use std::io::{stdin, stdout, Read, Write};
use crate::error::RuntimeError;
use super::lox_std::init_std;
use super::Value;
pub struct Runtime {
globals: HashMap<String, Value>,
in_stream: Box<dyn std::io::BufRead>,
out_stream: Box<dyn std::io::Write>,
}
impl Runtime {
pub fn new(in_stream: Box<dyn std::io::Read>, out_stream: Box<dyn std::io::Write>) -> Self {
let in_stream = Box::new(std::io::BufReader::new(in_stream));
let mut runtime = Runtime {
globals: HashMap::new(),
in_stream,
out_stream,
};
init_std(&mut runtime);
runtime
}
pub fn globals(&self) -> &HashMap<String, Value> {
&self.globals
}
pub fn get_global(&self, name: &str) -> Result<Value, RuntimeError> {
self.globals
.get(name)
.cloned()
.ok_or_else(|| RuntimeError::GlobalNotDefined { name: name.to_owned() })
}
pub fn define_global(&mut self, name: impl Into<String>, value: Value) {
let name = name.into();
self.globals.insert(name, value);
}
pub fn assign_global(&mut self, name: &str, value: Value) -> Result<(), RuntimeError> {
if let Some(old_value) = self.globals.get_mut(name) {
*old_value = value;
Ok(())
} else {
Err(RuntimeError::GlobalNotDefined { name: name.to_owned() })
}
}
}
impl Default for Runtime {
fn default() -> Self {
Runtime::new(Box::new(std::io::BufReader::new(stdin())), Box::new(stdout()))
}
}
impl std::fmt::Debug for Runtime {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("Runtime").field("globals", &self.globals).finish()
}
}
impl Display for Runtime {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "Globals:")?;
for (name, value) in self.globals.iter() {
write!(f, "\n\t{name} = {value}")?;
}
Ok(())
}
}
impl Drop for Runtime {
fn drop(&mut self) {
self.out_stream.flush().unwrap();
}
}
impl Read for Runtime {
fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
self.in_stream.read(buf)
}
}
impl Write for Runtime {
fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
self.out_stream.write(buf)
}
fn flush(&mut self) -> std::io::Result<()> {
self.out_stream.flush()
}
}

View file

@ -2,11 +2,14 @@ use std::cell::UnsafeCell;
use std::fmt::{Debug, Display};
use std::rc::Rc;
use crate::LoxClass;
use super::function::LoxExternFunction;
use super::LoxFunction;
#[derive(Debug, Clone)]
pub enum Value {
Class(Rc<LoxClass>),
Function(Rc<LoxFunction>),
ExternFunction(Rc<LoxExternFunction>),
String(Rc<String>),
@ -16,6 +19,11 @@ pub enum Value {
}
impl Value {
pub fn class(class: LoxClass) -> Self {
let class = Rc::new(class);
Value::Class(class)
}
pub fn function(fun: LoxFunction) -> Self {
let fun = Rc::new(fun);
Value::Function(fun)
@ -39,6 +47,7 @@ impl Value {
impl Display for Value {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
Value::Class(class) => write!(f, "{class}"),
Value::Function(fun) => write!(f, "{fun}"),
Value::ExternFunction(ext_fun) => write!(f, "{ext_fun}"),
Value::String(s) => write!(f, "\"{s}\""),
@ -66,14 +75,14 @@ impl PartialEq for Value {
/*====================================================================================================================*/
#[derive(Clone)]
pub struct HeapValue {
pub struct HeapedValue {
inner: Rc<UnsafeCell<Value>>,
}
impl HeapValue {
impl HeapedValue {
pub fn new(value: Value) -> Self {
let inner = Rc::new(UnsafeCell::new(value));
HeapValue { inner }
HeapedValue { inner }
}
pub fn get_clone(&self) -> Value {
@ -93,13 +102,13 @@ impl HeapValue {
}
}
impl Debug for HeapValue {
impl Debug for HeapedValue {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("HeapValue").field("inner", &self.get_clone()).finish()
}
}
impl Display for HeapValue {
impl Display for HeapedValue {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
write!(f, "{}", self.get_clone())
}

View file

@ -1,125 +0,0 @@
use thiserror::Error;
use crate::interpreter::Value;
use crate::lexer::Token;
use crate::misc::CodePos;
use crate::parser::{BinaryOp, Expr, UnaryOp};
#[derive(Error, Debug)]
pub enum LexerError {
#[error("Unexpected character '{c}' at {code_pos}.")]
UnexpectedCharacter { c: char, code_pos: CodePos },
#[error("Unterminated string literal starting at {code_pos}.")]
UnterminatedStringLiteral { code_pos: CodePos },
#[error("Unterminated block comment starting at {code_pos}.")]
UnterminatedBlockComment { code_pos: CodePos },
#[error("Invalid number literal {lexeme} at {code_pos}: {msg}")]
InvalidNumberLiteral {
lexeme: String,
msg: String,
code_pos: CodePos,
},
}
#[derive(Error, Debug)]
pub enum ParserError {
#[error("Token stream ended unexpectedly.")]
TokenStreamEnded,
#[error("Expected a primary expression, but found a {token} token instead at {0}.", token.code_pos)]
ExpectedPrimary { token: Token },
#[error("Missing semicolon at {code_pos}")]
MissingSemicolon { code_pos: CodePos },
#[error("Expected variable name at {0}, got {token} instead", token.code_pos)]
ExpectedVarName { token: Token },
#[error("Can't assign to {expr} at {code_pos}")]
InvalidAssignment { expr: Expr, code_pos: CodePos },
#[error("Missing closing curly brace at {code_pos}")]
MissingRightBrace { code_pos: CodePos },
#[error("Missing closing parenthesis at {code_pos}")]
MissingRightParen { code_pos: CodePos },
#[error("Missing parenthesis after if at {code_pos}")]
MissingParenAfterIf { code_pos: CodePos },
#[error("Missing parenthesis after while at {code_pos}")]
MissingParenAfterWhile { code_pos: CodePos },
#[error("Missing parenthesis after for at {code_pos}")]
MissingParenAfterFor { code_pos: CodePos },
#[error("Call at {code_pos} has too many arguments")]
TooManyArguments { code_pos: CodePos },
#[error("{msg} at {code_pos}")]
MissingIdentifier { msg: String, code_pos: CodePos },
#[error("Missing arguments to function declaration at {code_pos}")]
MissingFunctionArgs { code_pos: CodePos },
#[error("Missing body to function declaration at {code_pos}")]
MissingFunctionBody { code_pos: CodePos },
#[error("Function declaration at {code_pos} has too many parameters")]
TooManyParams { code_pos: CodePos },
}
#[derive(Error, Debug)]
pub enum RuntimeError {
#[error("Unary operator {op} had invalid argument {arg}")]
UnaryOpInvalidArgument { op: UnaryOp, arg: Value },
#[error("Binary operator {op} had invalid arguments {left} and {right}")]
BinaryOpInvalidArguments { left: Value, op: BinaryOp, right: Value },
#[error("Division by zero")]
DivisionByZero,
#[error("Name {name} is not defined")]
NameNotDefined { name: String },
#[error("{callee} is not callable")]
NotCallable { callee: Value },
#[error("{name}() takes {arity} args, but {given} were given.")]
WrongArity { name: String, arity: usize, given: usize },
#[error("Extern function call to {name} failed: {msg}")]
ExtFunCallFailed { name: String, msg: String },
#[error("Uncaught break statement")]
Break,
#[error("Uncaught return statement")]
Return { value: Value },
#[error("Exit with exit code {exit_code}")]
Exit { exit_code: i32 },
}
#[derive(Error, Debug)]
#[allow(clippy::enum_variant_names)]
pub enum LoxError {
#[error("{0}", format_multiple_errors(inner))]
LexerError { inner: Vec<LexerError> },
#[error("{0}", format_multiple_errors(inner))]
ParserError { inner: Vec<ParserError> },
#[error("{inner}")]
RuntimeError { inner: RuntimeError },
#[error("Called exit() with exit code {exit_code}")]
Exit { exit_code: i32 },
}
fn format_multiple_errors(errs: &Vec<impl std::error::Error>) -> String {
let msg = if errs.len() == 1 {
format!("{}", errs[0])
} else {
let msgs: Vec<String> = errs.iter().map(|err| format!("{}", err)).collect();
msgs.join("\n")
};
msg
}
impl From<Vec<LexerError>> for LoxError {
fn from(lexer_errs: Vec<LexerError>) -> Self {
LoxError::LexerError { inner: lexer_errs }
}
}
impl From<Vec<ParserError>> for LoxError {
fn from(parser_errs: Vec<ParserError>) -> Self {
LoxError::ParserError { inner: parser_errs }
}
}
impl From<RuntimeError> for LoxError {
fn from(runtime_err: RuntimeError) -> Self {
match runtime_err {
RuntimeError::Exit { exit_code } => LoxError::Exit { exit_code },
_ => LoxError::RuntimeError { inner: runtime_err },
}
}
}

View file

@ -1,146 +0,0 @@
use std::borrow::Borrow;
use std::collections::HashMap;
use crate::error::RuntimeError;
use super::lox_std::init_std;
use super::value::HeapValue;
use super::Value;
pub type Scope = HashMap<String, HeapValue>;
pub struct Environment {
globals: Scope,
// scopes: Vec<Scope>,
frames: Vec<Frame>,
}
impl Environment {
pub fn new() -> Self {
let mut env = Environment {
globals: HashMap::new(),
frames: vec![Frame::new_global()],
};
init_std(&mut env);
env
}
fn current_frame(&self) -> &Frame {
self.frames.last().unwrap()
}
fn current_frame_mut(&mut self) -> &mut Frame {
self.frames.last_mut().unwrap()
}
pub fn globals(&self) -> &Scope {
&self.globals
}
pub fn get(&self, name: &str) -> Result<Value, RuntimeError> {
if let Some(value) = self.current_frame().get(name) {
return Ok(value);
}
match self.globals.get(name) {
Some(heap_value) => Ok(heap_value.get_clone()),
None => Err(RuntimeError::NameNotDefined { name: name.to_owned() }),
}
}
pub fn define(&mut self, name: impl Into<String> + Borrow<str>, value: Value) {
if let Err(value) = self.current_frame_mut().try_define(name.borrow(), value) {
self.globals.insert(name.into(), HeapValue::new(value));
}
}
pub fn assign(&mut self, name: &str, value: Value) -> Result<(), RuntimeError> {
let value = match self.current_frame_mut().try_assign(name, value) {
Ok(()) => return Ok(()),
Err(value) => value,
};
if let Some(var) = self.globals.get_mut(name) {
// *var = value;
var.replace(value);
Ok(())
} else {
Err(RuntimeError::NameNotDefined { name: name.to_owned() })
}
}
pub fn enter_scope(&mut self) {
self.current_frame_mut().enter_scope();
}
pub fn exit_scope(&mut self) {
self.current_frame_mut().exit_scope();
}
pub fn push_frame(&mut self, base_scope: Scope) {
self.frames.push(Frame::new(base_scope));
}
pub fn pop_frame(&mut self) {
self.frames.pop().expect("Tried to pop global frame");
}
}
/*====================================================================================================================*/
struct Frame {
scopes: Vec<Scope>,
}
impl Frame {
fn new(base_scope: Scope) -> Self {
Frame {
scopes: vec![base_scope],
}
}
fn new_global() -> Self {
Frame { scopes: Vec::new() }
}
fn enter_scope(&mut self) {
self.scopes.push(Scope::new());
}
fn exit_scope(&mut self) {
self.scopes.pop().expect("Tried to exit scope, but no scope to exit");
}
fn get(&self, name: &str) -> Option<Value> {
for scope in self.scopes.iter().rev() {
if let Some(heap_value) = scope.get(name) {
return Some(heap_value.get_clone());
}
}
None
}
fn try_define(&mut self, name: impl Into<String> + Borrow<str>, value: Value) -> Result<(), Value> {
if let Some(scope) = self.scopes.last_mut() {
scope.insert(name.into(), HeapValue::new(value));
Ok(())
} else {
Err(value)
}
}
fn try_assign(&mut self, name: &str, value: Value) -> Result<(), Value> {
for scope in self.scopes.iter_mut().rev() {
if let Some(heap_value) = scope.get_mut(name) {
heap_value.replace(value);
return Ok(());
}
}
Err(value)
}
}

View file

@ -1,10 +0,0 @@
mod environment;
mod function;
mod interpret;
mod lox_std;
mod run;
mod value;
pub use function::LoxFunction;
pub use run::interpreter_main;
pub use value::Value;

View file

@ -1,9 +1,31 @@
mod error;
mod interpreter;
mod lexer;
mod misc;
mod parser;
use clap::{ArgAction, Parser};
use rlox2_interpreter::{run_file, run_repl, Runtime};
#[derive(Parser, Debug)]
struct CliArgs {
#[arg()]
file_name: Option<String>,
#[arg(short, action = ArgAction::SetTrue)]
interactive: bool,
}
fn main() {
interpreter::interpreter_main();
interpreter_main();
}
pub fn interpreter_main() {
let cli_args = CliArgs::parse();
let mut runtime = Runtime::default();
if let Some(file_name) = cli_args.file_name {
run_file(&mut runtime, &file_name);
if cli_args.interactive {
run_repl(&mut runtime);
}
} else {
run_repl(&mut runtime);
}
}