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authorVincent Ambo <mail@tazj.in>2022-02-07T16·29+0300
committerclbot <clbot@tvl.fyi>2022-02-07T16·58+0000
commit0d0b43ed8819e66a0888eb6d1d1f47b171ae62e0 (patch)
tree305c04d3fe26c92ed7037f0b0f41f38444ce83ea /users/tazjin/rlox/src
parent8b8c98380e85b2057a3c35ce3d76879fab4266b0 (diff)
fix(users/tazjin): rustfmt code with non-default settings r/3776
rustfmt only sometimes detects path-based nested config
files (probably some kind of race?), so my users folder uses a
separate formatting check for rustfmt to avoid flaky CI. Enough flakes
around already ...

Change-Id: Ifd862f9974f071b3a256643dd8e56c019116156a
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5242
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Diffstat (limited to 'users/tazjin/rlox/src')
-rw-r--r--users/tazjin/rlox/src/bytecode/compiler.rs89
-rw-r--r--users/tazjin/rlox/src/bytecode/mod.rs5
-rw-r--r--users/tazjin/rlox/src/bytecode/vm.rs33
-rw-r--r--users/tazjin/rlox/src/main.rs17
-rw-r--r--users/tazjin/rlox/src/scanner.rs13
-rw-r--r--users/tazjin/rlox/src/treewalk/interpreter.rs106
-rw-r--r--users/tazjin/rlox/src/treewalk/parser.rs122
-rw-r--r--users/tazjin/rlox/src/treewalk/resolver.rs43
8 files changed, 140 insertions, 288 deletions
diff --git a/users/tazjin/rlox/src/bytecode/compiler.rs b/users/tazjin/rlox/src/bytecode/compiler.rs
index 3e8a80653f91..89584f19d720 100644
--- a/users/tazjin/rlox/src/bytecode/compiler.rs
+++ b/users/tazjin/rlox/src/bytecode/compiler.rs
@@ -63,9 +63,11 @@ enum Precedence {
     Equality,   // == !=
     Comparison, // < > <= >=
     Term,       // + -
-    Factor,     // * /
-    Unary,      // ! -
-    Call,       // . ()
+    Factor,     //
+    // 
+    // * /
+    Unary, // ! -
+    Call,  // . ()
     Primary,
 }
 
@@ -78,11 +80,7 @@ struct ParseRule<T: Iterator<Item = Token>> {
 }
 
 impl<T: Iterator<Item = Token>> ParseRule<T> {
-    fn new(
-        prefix: Option<ParseFn<T>>,
-        infix: Option<ParseFn<T>>,
-        precedence: Precedence,
-    ) -> Self {
+    fn new(prefix: Option<ParseFn<T>>, infix: Option<ParseFn<T>>, precedence: Precedence) -> Self {
         ParseRule {
             prefix,
             infix,
@@ -105,18 +103,16 @@ impl Precedence {
             Precedence::Factor => Precedence::Unary,
             Precedence::Unary => Precedence::Call,
             Precedence::Call => Precedence::Primary,
-            Precedence::Primary => panic!(
-                "invalid parser state: no higher precedence than Primary"
-            ),
+            Precedence::Primary => {
+                panic!("invalid parser state: no higher precedence than Primary")
+            }
         }
     }
 }
 
 fn rule_for<T: Iterator<Item = Token>>(token: &TokenKind) -> ParseRule<T> {
     match token {
-        TokenKind::LeftParen => {
-            ParseRule::new(Some(Compiler::grouping), None, Precedence::None)
-        }
+        TokenKind::LeftParen => ParseRule::new(Some(Compiler::grouping), None, Precedence::None),
 
         TokenKind::Minus => ParseRule::new(
             Some(Compiler::unary),
@@ -124,57 +120,33 @@ fn rule_for<T: Iterator<Item = Token>>(token: &TokenKind) -> ParseRule<T> {
             Precedence::Term,
         ),
 
-        TokenKind::Plus => {
-            ParseRule::new(None, Some(Compiler::binary), Precedence::Term)
-        }
+        TokenKind::Plus => ParseRule::new(None, Some(Compiler::binary), Precedence::Term),
 
-        TokenKind::Slash => {
-            ParseRule::new(None, Some(Compiler::binary), Precedence::Factor)
-        }
+        TokenKind::Slash => ParseRule::new(None, Some(Compiler::binary), Precedence::Factor),
 
-        TokenKind::Star => {
-            ParseRule::new(None, Some(Compiler::binary), Precedence::Factor)
-        }
+        TokenKind::Star => ParseRule::new(None, Some(Compiler::binary), Precedence::Factor),
 
-        TokenKind::Number(_) => {
-            ParseRule::new(Some(Compiler::number), None, Precedence::None)
-        }
+        TokenKind::Number(_) => ParseRule::new(Some(Compiler::number), None, Precedence::None),
 
-        TokenKind::True => {
-            ParseRule::new(Some(Compiler::literal), None, Precedence::None)
-        }
+        TokenKind::True => ParseRule::new(Some(Compiler::literal), None, Precedence::None),
 
-        TokenKind::False => {
-            ParseRule::new(Some(Compiler::literal), None, Precedence::None)
-        }
+        TokenKind::False => ParseRule::new(Some(Compiler::literal), None, Precedence::None),
 
-        TokenKind::Nil => {
-            ParseRule::new(Some(Compiler::literal), None, Precedence::None)
-        }
+        TokenKind::Nil => ParseRule::new(Some(Compiler::literal), None, Precedence::None),
 
-        TokenKind::Bang => {
-            ParseRule::new(Some(Compiler::unary), None, Precedence::None)
-        }
+        TokenKind::Bang => ParseRule::new(Some(Compiler::unary), None, Precedence::None),
 
-        TokenKind::BangEqual => {
-            ParseRule::new(None, Some(Compiler::binary), Precedence::Equality)
-        }
+        TokenKind::BangEqual => ParseRule::new(None, Some(Compiler::binary), Precedence::Equality),
 
-        TokenKind::EqualEqual => {
-            ParseRule::new(None, Some(Compiler::binary), Precedence::Equality)
-        }
+        TokenKind::EqualEqual => ParseRule::new(None, Some(Compiler::binary), Precedence::Equality),
 
-        TokenKind::Greater => {
-            ParseRule::new(None, Some(Compiler::binary), Precedence::Comparison)
-        }
+        TokenKind::Greater => ParseRule::new(None, Some(Compiler::binary), Precedence::Comparison),
 
         TokenKind::GreaterEqual => {
             ParseRule::new(None, Some(Compiler::binary), Precedence::Comparison)
         }
 
-        TokenKind::Less => {
-            ParseRule::new(None, Some(Compiler::binary), Precedence::Comparison)
-        }
+        TokenKind::Less => ParseRule::new(None, Some(Compiler::binary), Precedence::Comparison),
 
         TokenKind::LessEqual => {
             ParseRule::new(None, Some(Compiler::binary), Precedence::Comparison)
@@ -184,9 +156,7 @@ fn rule_for<T: Iterator<Item = Token>>(token: &TokenKind) -> ParseRule<T> {
             ParseRule::new(Some(Compiler::variable), None, Precedence::None)
         }
 
-        TokenKind::String(_) => {
-            ParseRule::new(Some(Compiler::string), None, Precedence::None)
-        }
+        TokenKind::String(_) => ParseRule::new(Some(Compiler::string), None, Precedence::None),
 
         _ => ParseRule::new(None, None, Precedence::None),
     }
@@ -236,9 +206,7 @@ impl<T: Iterator<Item = Token>> Compiler<T> {
 
     fn define_variable(&mut self, var: Option<ConstantIdx>) -> LoxResult<()> {
         if self.locals.scope_depth == 0 {
-            self.emit_op(OpCode::OpDefineGlobal(
-                var.expect("should be global"),
-            ));
+            self.emit_op(OpCode::OpDefineGlobal(var.expect("should be global")));
         } else {
             self.locals
                 .locals
@@ -305,9 +273,7 @@ impl<T: Iterator<Item = Token>> Compiler<T> {
     }
 
     fn block(&mut self) -> LoxResult<()> {
-        while !self.check(&TokenKind::RightBrace)
-            && !self.check(&TokenKind::Eof)
-        {
+        while !self.check(&TokenKind::RightBrace) && !self.check(&TokenKind::Eof) {
             self.declaration()?;
         }
 
@@ -712,9 +678,8 @@ impl<T: Iterator<Item = Token>> Compiler<T> {
 
 pub fn compile(code: &str) -> Result<(Interner, Chunk), Vec<Error>> {
     let chars = code.chars().collect::<Vec<char>>();
-    let tokens = scanner::scan(&chars).map_err(|errors| {
-        errors.into_iter().map(Into::into).collect::<Vec<Error>>()
-    })?;
+    let tokens = scanner::scan(&chars)
+        .map_err(|errors| errors.into_iter().map(Into::into).collect::<Vec<Error>>())?;
 
     let mut compiler = Compiler {
         tokens: tokens.into_iter().peekable(),
diff --git a/users/tazjin/rlox/src/bytecode/mod.rs b/users/tazjin/rlox/src/bytecode/mod.rs
index c6f3a737aef8..117f17824ac6 100644
--- a/users/tazjin/rlox/src/bytecode/mod.rs
+++ b/users/tazjin/rlox/src/bytecode/mod.rs
@@ -23,10 +23,7 @@ impl crate::Lox for Interpreter {
         Interpreter {}
     }
 
-    fn interpret(
-        &mut self,
-        code: String,
-    ) -> Result<Self::Value, Vec<Self::Error>> {
+    fn interpret(&mut self, code: String) -> Result<Self::Value, Vec<Self::Error>> {
         let (strings, chunk) = compiler::compile(&code)?;
         vm::interpret(strings, chunk).map_err(|e| vec![e])
     }
diff --git a/users/tazjin/rlox/src/bytecode/vm.rs b/users/tazjin/rlox/src/bytecode/vm.rs
index d287ec7cb8c5..30ffebc79cf7 100644
--- a/users/tazjin/rlox/src/bytecode/vm.rs
+++ b/users/tazjin/rlox/src/bytecode/vm.rs
@@ -118,12 +118,7 @@ impl VM {
 
                 OpCode::OpNegate => {
                     let v = self.pop();
-                    with_type!(
-                        self,
-                        v,
-                        Value::Number(num),
-                        self.push(Value::Number(-num))
-                    );
+                    with_type!(self, v, Value::Number(num), self.push(Value::Number(-num)));
                 }
 
                 OpCode::OpSubtract => binary_op!(self, Number, -),
@@ -141,15 +136,18 @@ impl VM {
                             self.push(Value::String(new_s.into()));
                         }
 
-                        (Value::Number(n_a), Value::Number(n_b)) =>
-                            self.push(Value::Number(n_a + n_b)),
+                        (Value::Number(n_a), Value::Number(n_b)) => {
+                            self.push(Value::Number(n_a + n_b))
+                        }
 
-                        _ => return Err(Error {
-                            line: self.chunk.get_line(self.ip - 1),
-                            kind: ErrorKind::TypeError(
-                                "'+' operator only works on strings and numbers".into()
-                            ),
-                        })
+                        _ => {
+                            return Err(Error {
+                                line: self.chunk.get_line(self.ip - 1),
+                                kind: ErrorKind::TypeError(
+                                    "'+' operator only works on strings and numbers".into(),
+                                ),
+                            })
+                        }
                     }
                 }
 
@@ -205,8 +203,7 @@ impl VM {
                         self.stack.len() > local_idx.0,
                         "stack is not currently large enough for local"
                     );
-                    self.stack[local_idx.0] =
-                        self.stack.last().unwrap().clone();
+                    self.stack[local_idx.0] = self.stack.last().unwrap().clone();
                 }
 
                 OpCode::OpJumpPlaceholder(_) => {
@@ -255,9 +252,7 @@ impl VM {
     fn print_value(&self, val: Value) -> String {
         match val {
             Value::String(LoxString::Heap(s)) => s,
-            Value::String(LoxString::Interned(id)) => {
-                self.strings.lookup(id).into()
-            }
+            Value::String(LoxString::Interned(id)) => self.strings.lookup(id).into(),
             _ => format!("{:?}", val),
         }
     }
diff --git a/users/tazjin/rlox/src/main.rs b/users/tazjin/rlox/src/main.rs
index 2d8cf4f354ea..ee61ae01a106 100644
--- a/users/tazjin/rlox/src/main.rs
+++ b/users/tazjin/rlox/src/main.rs
@@ -1,8 +1,5 @@
-use std::env;
-use std::fs;
-use std::io;
 use std::io::Write;
-use std::process;
+use std::{env, fs, io, process};
 
 mod bytecode;
 mod scanner;
@@ -15,10 +12,7 @@ pub trait Lox {
     type Error: std::fmt::Display;
 
     fn create() -> Self;
-    fn interpret(
-        &mut self,
-        source: String,
-    ) -> Result<Self::Value, Vec<Self::Error>>;
+    fn interpret(&mut self, source: String) -> Result<Self::Value, Vec<Self::Error>>;
 }
 
 fn main() {
@@ -29,9 +23,7 @@ fn main() {
     }
 
     match env::var("LOX_INTERPRETER").as_ref().map(String::as_str) {
-        Ok("treewalk") => {
-            pick::<treewalk::interpreter::Interpreter>(args.nth(1))
-        }
+        Ok("treewalk") => pick::<treewalk::interpreter::Interpreter>(args.nth(1)),
         _ => pick::<bytecode::Interpreter>(args.nth(1)),
     }
 }
@@ -46,8 +38,7 @@ fn pick<I: Lox>(file_arg: Option<String>) {
 
 // Run Lox code from a file and print results to stdout
 fn run_file<I: Lox>(file: &str) {
-    let contents =
-        fs::read_to_string(file).expect("failed to read the input file");
+    let contents = fs::read_to_string(file).expect("failed to read the input file");
     let mut lox = I::create();
     run(&mut lox, contents);
 }
diff --git a/users/tazjin/rlox/src/scanner.rs b/users/tazjin/rlox/src/scanner.rs
index 4e8f07b61f5e..314b56d6d380 100644
--- a/users/tazjin/rlox/src/scanner.rs
+++ b/users/tazjin/rlox/src/scanner.rs
@@ -106,15 +106,9 @@ impl<'a> Scanner<'a> {
 
             // possible multi-character tokens
             '!' => self.add_if_next('=', TokenKind::BangEqual, TokenKind::Bang),
-            '=' => {
-                self.add_if_next('=', TokenKind::EqualEqual, TokenKind::Equal)
-            }
+            '=' => self.add_if_next('=', TokenKind::EqualEqual, TokenKind::Equal),
             '<' => self.add_if_next('=', TokenKind::LessEqual, TokenKind::Less),
-            '>' => self.add_if_next(
-                '=',
-                TokenKind::GreaterEqual,
-                TokenKind::Greater,
-            ),
+            '>' => self.add_if_next('=', TokenKind::GreaterEqual, TokenKind::Greater),
 
             '/' => {
                 // support comments until EOL by discarding characters
@@ -234,8 +228,7 @@ impl<'a> Scanner<'a> {
             self.advance();
         }
 
-        let ident: String =
-            self.source[self.start..self.current].iter().collect();
+        let ident: String = self.source[self.start..self.current].iter().collect();
 
         // Determine whether this is an identifier, or a keyword:
         let token_kind = match ident.as_str() {
diff --git a/users/tazjin/rlox/src/treewalk/interpreter.rs b/users/tazjin/rlox/src/treewalk/interpreter.rs
index d9fe33661684..3285775bbec6 100644
--- a/users/tazjin/rlox/src/treewalk/interpreter.rs
+++ b/users/tazjin/rlox/src/treewalk/interpreter.rs
@@ -34,11 +34,7 @@ impl Callable {
         }
     }
 
-    fn call(
-        &self,
-        lox: &mut Interpreter,
-        args: Vec<Value>,
-    ) -> Result<Value, Error> {
+    fn call(&self, lox: &mut Interpreter, args: Vec<Value>) -> Result<Value, Error> {
         match self {
             Callable::Builtin(builtin) => builtin.call(args),
 
@@ -50,10 +46,8 @@ impl Callable {
                     fn_env.define(param, value)?;
                 }
 
-                let result = lox.interpret_block_with_env(
-                    Some(Rc::new(RwLock::new(fn_env))),
-                    &func.body,
-                );
+                let result =
+                    lox.interpret_block_with_env(Some(Rc::new(RwLock::new(fn_env))), &func.body);
 
                 match result {
                     // extract returned values if applicable
@@ -109,22 +103,13 @@ pub struct Environment {
 }
 
 impl Environment {
-    fn define(
-        &mut self,
-        name: &scanner::Token,
-        value: Value,
-    ) -> Result<(), Error> {
+    fn define(&mut self, name: &scanner::Token, value: Value) -> Result<(), Error> {
         let ident = identifier_str(name)?;
         self.values.insert(ident.into(), value);
         Ok(())
     }
 
-    fn get(
-        &self,
-        ident: &str,
-        line: usize,
-        depth: usize,
-    ) -> Result<Value, Error> {
+    fn get(&self, ident: &str, line: usize, depth: usize) -> Result<Value, Error> {
         if depth > 0 {
             match &self.enclosing {
                 None => {
@@ -137,9 +122,7 @@ impl Environment {
                     })
                 }
                 Some(parent) => {
-                    let env = parent
-                        .read()
-                        .expect("fatal: environment lock poisoned");
+                    let env = parent.read().expect("fatal: environment lock poisoned");
                     return env.get(ident, line, depth - 1);
                 }
             }
@@ -154,11 +137,7 @@ impl Environment {
             })
     }
 
-    fn assign(
-        &mut self,
-        name: &scanner::Token,
-        value: Value,
-    ) -> Result<(), Error> {
+    fn assign(&mut self, name: &scanner::Token, value: Value) -> Result<(), Error> {
         let ident = identifier_str(name)?;
 
         match self.values.get_mut(ident) {
@@ -242,22 +221,14 @@ impl Lox for Interpreter {
 
 impl Interpreter {
     // Environment modification helpers
-    fn define_var(
-        &mut self,
-        name: &scanner::Token,
-        value: Value,
-    ) -> Result<(), Error> {
+    fn define_var(&mut self, name: &scanner::Token, value: Value) -> Result<(), Error> {
         self.env
             .write()
             .expect("environment lock is poisoned")
             .define(name, value)
     }
 
-    fn assign_var(
-        &mut self,
-        name: &scanner::Token,
-        value: Value,
-    ) -> Result<(), Error> {
+    fn assign_var(&mut self, name: &scanner::Token, value: Value) -> Result<(), Error> {
         self.env
             .write()
             .expect("environment lock is poisoned")
@@ -271,11 +242,10 @@ impl Interpreter {
             kind: ErrorKind::UndefinedVariable(ident.into()),
         })?;
 
-        self.env.read().expect("environment lock is poisoned").get(
-            ident,
-            var.name.line,
-            depth,
-        )
+        self.env
+            .read()
+            .expect("environment lock is poisoned")
+            .get(ident, var.name.line, depth)
     }
 
     /// Interpret the block in the supplied environment. If no
@@ -324,16 +294,10 @@ impl Interpreter {
                 Value::Literal(Literal::String(output))
             }
             Statement::Var(var) => return self.interpret_var(var),
-            Statement::Block(block) => {
-                return self.interpret_block_with_env(None, block)
-            }
+            Statement::Block(block) => return self.interpret_block_with_env(None, block),
             Statement::If(if_stmt) => return self.interpret_if(if_stmt),
-            Statement::While(while_stmt) => {
-                return self.interpret_while(while_stmt)
-            }
-            Statement::Function(func) => {
-                return self.interpret_function(func.clone())
-            }
+            Statement::While(while_stmt) => return self.interpret_while(while_stmt),
+            Statement::Function(func) => return self.interpret_function(func.clone()),
             Statement::Return(ret) => {
                 return Err(Error {
                     line: 0,
@@ -348,9 +312,7 @@ impl Interpreter {
     fn interpret_var(&mut self, var: &parser::Var) -> Result<Value, Error> {
         let init = var.initialiser.as_ref().ok_or_else(|| Error {
             line: var.name.line,
-            kind: ErrorKind::InternalError(
-                "missing variable initialiser".into(),
-            ),
+            kind: ErrorKind::InternalError("missing variable initialiser".into()),
         })?;
         let value = self.eval(init)?;
         self.define_var(&var.name, value.clone())?;
@@ -369,10 +331,7 @@ impl Interpreter {
         }
     }
 
-    fn interpret_while(
-        &mut self,
-        stmt: &parser::While,
-    ) -> Result<Value, Error> {
+    fn interpret_while(&mut self, stmt: &parser::While) -> Result<Value, Error> {
         let mut value = Value::Literal(Literal::Nil);
         while eval_truthy(&self.eval(&stmt.condition)?) {
             value = self.interpret_stmt(&stmt.body)?;
@@ -381,10 +340,7 @@ impl Interpreter {
         Ok(value)
     }
 
-    fn interpret_function(
-        &mut self,
-        func: Rc<parser::Function>,
-    ) -> Result<Value, Error> {
+    fn interpret_function(&mut self, func: Rc<parser::Function>) -> Result<Value, Error> {
         let name = func.name.clone();
         let value = Value::Callable(Callable::Function {
             func,
@@ -414,9 +370,7 @@ impl Interpreter {
             (TokenKind::Minus, Value::Literal(Literal::Number(num))) => {
                 Ok(Literal::Number(-num).into())
             }
-            (TokenKind::Bang, right) => {
-                Ok(Literal::Boolean(!eval_truthy(&right)).into())
-            }
+            (TokenKind::Bang, right) => Ok(Literal::Boolean(!eval_truthy(&right)).into()),
 
             (op, right) => Err(Error {
                 line: expr.operator.line,
@@ -478,10 +432,7 @@ impl Interpreter {
         Ok(value)
     }
 
-    fn eval_logical(
-        &mut self,
-        logical: &parser::Logical,
-    ) -> Result<Value, Error> {
+    fn eval_logical(&mut self, logical: &parser::Logical) -> Result<Value, Error> {
         let left = eval_truthy(&self.eval(&logical.left)?);
         let right = eval_truthy(&self.eval(&logical.right)?);
 
@@ -490,10 +441,7 @@ impl Interpreter {
             TokenKind::Or => Ok(Literal::Boolean(left || right).into()),
             kind => Err(Error {
                 line: logical.operator.line,
-                kind: ErrorKind::InternalError(format!(
-                    "Invalid logical operator: {:?}",
-                    kind
-                )),
+                kind: ErrorKind::InternalError(format!("Invalid logical operator: {:?}", kind)),
             }),
         }
     }
@@ -504,10 +452,7 @@ impl Interpreter {
             Value::Literal(v) => {
                 return Err(Error {
                     line: call.paren.line,
-                    kind: ErrorKind::RuntimeError(format!(
-                        "not callable: {:?}",
-                        v
-                    )),
+                    kind: ErrorKind::RuntimeError(format!("not callable: {:?}", v)),
                 })
             }
         };
@@ -546,10 +491,7 @@ fn eval_truthy(lit: &Value) -> bool {
     }
 }
 
-fn set_enclosing_env(
-    this: &RwLock<Environment>,
-    parent: Rc<RwLock<Environment>>,
-) {
+fn set_enclosing_env(this: &RwLock<Environment>, parent: Rc<RwLock<Environment>>) {
     this.write()
         .expect("environment lock is poisoned")
         .enclosing = Some(parent);
diff --git a/users/tazjin/rlox/src/treewalk/parser.rs b/users/tazjin/rlox/src/treewalk/parser.rs
index 003cc34b4665..5794b42d1577 100644
--- a/users/tazjin/rlox/src/treewalk/parser.rs
+++ b/users/tazjin/rlox/src/treewalk/parser.rs
@@ -124,56 +124,54 @@ pub enum Statement {
 
 // Parser
 
-/*
-program        → declaration* EOF ;
-
-declaration    → funDecl
-               | varDecl
-               | statement ;
-
-funDecl        → "fun" function ;
-function       → IDENTIFIER "(" parameters? ")" block ;
-parameters     → IDENTIFIER ( "," IDENTIFIER )* ;
-
-
-statement      → exprStmt
-               | forStmt
-               | ifStmt
-               | printStmt
-               | returnStmt
-               | whileStmt
-               | block ;
-
-forStmt        → "for" "(" ( varDecl | exprStmt | ";" )
-                 expression? ";"
-                 expression? ")" statement ;
-
-returnStmt     → "return" expression? ";" ;
-
-whileStmt      → "while" "(" expression ")" statement ;
-
-exprStmt       → expression ";" ;
-
-ifStmt         → "if" "(" expression ")" statement
-               ( "else" statement )? ;
-
-printStmt      → "print" expression ";" ;
-
-expression     → assignment ;
-assignment     → IDENTIFIER "=" assignment
-               | logic_or ;
-logic_or       → logic_and ( "or" logic_and )* ;
-logic_and      → equality ( "and" equality )* ;
-equality       → comparison ( ( "!=" | "==" ) comparison )* ;
-comparison     → term ( ( ">" | ">=" | "<" | "<=" ) term )* ;
-term           → factor ( ( "-" | "+" ) factor )* ;
-factor         → unary ( ( "/" | "*" ) unary )* ;
-unary          → ( "!" | "-" ) unary | call ;
-call           → primary ( "(" arguments? ")" )* ;
-arguments      → expression ( "," expression )* ;
-primary        → NUMBER | STRING | "true" | "false" | "nil"
-               | "(" expression ")" ;
-*/
+// program        → declaration* EOF ;
+//
+// declaration    → funDecl
+// | varDecl
+// | statement ;
+//
+// funDecl        → "fun" function ;
+// function       → IDENTIFIER "(" parameters? ")" block ;
+// parameters     → IDENTIFIER ( "," IDENTIFIER )* ;
+//
+//
+// statement      → exprStmt
+// | forStmt
+// | ifStmt
+// | printStmt
+// | returnStmt
+// | whileStmt
+// | block ;
+//
+// forStmt        → "for" "(" ( varDecl | exprStmt | ";" )
+// expression? ";"
+// expression? ")" statement ;
+//
+// returnStmt     → "return" expression? ";" ;
+//
+// whileStmt      → "while" "(" expression ")" statement ;
+//
+// exprStmt       → expression ";" ;
+//
+// ifStmt         → "if" "(" expression ")" statement
+// ( "else" statement )? ;
+//
+// printStmt      → "print" expression ";" ;
+//
+// expression     → assignment ;
+// assignment     → IDENTIFIER "=" assignment
+// | logic_or ;
+// logic_or       → logic_and ( "or" logic_and )* ;
+// logic_and      → equality ( "and" equality )* ;
+// equality       → comparison ( ( "!=" | "==" ) comparison )* ;
+// comparison     → term ( ( ">" | ">=" | "<" | "<=" ) term )* ;
+// term           → factor ( ( "-" | "+" ) factor )* ;
+// factor         → unary ( ( "/" | "*" ) unary )* ;
+// unary          → ( "!" | "-" ) unary | call ;
+// call           → primary ( "(" arguments? ")" )* ;
+// arguments      → expression ( "," expression )* ;
+// primary        → NUMBER | STRING | "true" | "false" | "nil"
+// | "(" expression ")" ;
 
 struct Parser {
     tokens: Vec<Token>,
@@ -213,9 +211,7 @@ impl Parser {
                 if params.len() >= 255 {
                     return Err(Error {
                         line: self.peek().line,
-                        kind: ErrorKind::InternalError(
-                            "255 parameter limit exceeded.".into(),
-                        ),
+                        kind: ErrorKind::InternalError("255 parameter limit exceeded.".into()),
                     });
                 }
 
@@ -429,10 +425,7 @@ impl Parser {
 
             return Err(Error {
                 line: equals.line,
-                kind: ErrorKind::InvalidAssignmentTarget(format!(
-                    "{:?}",
-                    equals
-                )),
+                kind: ErrorKind::InvalidAssignmentTarget(format!("{:?}", equals)),
             });
         }
 
@@ -495,9 +488,7 @@ impl Parser {
     }
 
     fn unary(&mut self) -> ExprResult {
-        if self.match_token(&TokenKind::Bang)
-            || self.match_token(&TokenKind::Minus)
-        {
+        if self.match_token(&TokenKind::Bang) || self.match_token(&TokenKind::Minus) {
             return Ok(Expr::Unary(Unary {
                 operator: self.previous().clone(),
                 right: Box::new(self.unary()?),
@@ -557,10 +548,7 @@ impl Parser {
 
             TokenKind::LeftParen => {
                 let expr = self.expression()?;
-                self.consume(
-                    &TokenKind::RightParen,
-                    ErrorKind::UnmatchedParens,
-                )?;
+                self.consume(&TokenKind::RightParen, ErrorKind::UnmatchedParens)?;
                 return Ok(Expr::Grouping(Grouping(Box::new(expr))));
             }
 
@@ -632,11 +620,7 @@ impl Parser {
         &self.tokens[self.current - 1]
     }
 
-    fn consume(
-        &mut self,
-        kind: &TokenKind,
-        err: ErrorKind,
-    ) -> Result<Token, Error> {
+    fn consume(&mut self, kind: &TokenKind, err: ErrorKind) -> Result<Token, Error> {
         if self.check_token(kind) {
             return Ok(self.advance());
         }
diff --git a/users/tazjin/rlox/src/treewalk/resolver.rs b/users/tazjin/rlox/src/treewalk/resolver.rs
index 8231ce5a9e58..3d12973aa089 100644
--- a/users/tazjin/rlox/src/treewalk/resolver.rs
+++ b/users/tazjin/rlox/src/treewalk/resolver.rs
@@ -56,13 +56,14 @@ impl<'a> Resolver<'a> {
                 // The resolver does not clone references, so unless
                 // the interpreter is called before the resolver this
                 // case should never happen.
-                None => return Err(Error {
-                    line: 0,
-                    kind: ErrorKind::InternalError(
-                        "multiple function references before interpretation"
-                            .into(),
-                    ),
-                }),
+                None => {
+                    return Err(Error {
+                        line: 0,
+                        kind: ErrorKind::InternalError(
+                            "multiple function references before interpretation".into(),
+                        ),
+                    })
+                }
             },
         }
     }
@@ -79,10 +80,7 @@ impl<'a> Resolver<'a> {
         Ok(())
     }
 
-    fn resolve_function(
-        &mut self,
-        func: &'a mut parser::Function,
-    ) -> Result<(), Error> {
+    fn resolve_function(&mut self, func: &'a mut parser::Function) -> Result<(), Error> {
         self.declare(&func.name.lexeme);
         self.define(&func.name.lexeme);
 
@@ -123,17 +121,13 @@ impl<'a> Resolver<'a> {
         }
     }
 
-    fn resolve_variable(
-        &mut self,
-        var: &'a mut parser::Variable,
-    ) -> Result<(), Error> {
+    fn resolve_variable(&mut self, var: &'a mut parser::Variable) -> Result<(), Error> {
         if let Some(scope) = self.scopes.last_mut() {
             if let Some(false) = scope.get(var.name.lexeme.as_str()) {
                 return Err(Error {
                     line: var.name.line,
                     kind: ErrorKind::StaticError(
-                        "can't read local variable in its own initialiser"
-                            .into(),
+                        "can't read local variable in its own initialiser".into(),
                     ),
                 });
             }
@@ -143,10 +137,7 @@ impl<'a> Resolver<'a> {
         Ok(())
     }
 
-    fn resolve_assign(
-        &mut self,
-        assign: &'a mut parser::Assign,
-    ) -> Result<(), Error> {
+    fn resolve_assign(&mut self, assign: &'a mut parser::Assign) -> Result<(), Error> {
         self.resolve_expr(&mut assign.value)?;
         assign.depth = self.resolve_local(&assign.name);
         Ok(())
@@ -162,10 +153,7 @@ impl<'a> Resolver<'a> {
         None
     }
 
-    fn resolve_call(
-        &mut self,
-        call: &'a mut parser::Call,
-    ) -> Result<(), Error> {
+    fn resolve_call(&mut self, call: &'a mut parser::Call) -> Result<(), Error> {
         self.resolve_expr(&mut call.callee)?;
 
         for arg in call.args.iter_mut() {
@@ -198,10 +186,7 @@ impl<'a> Resolver<'a> {
     }
 }
 
-pub fn resolve(
-    globals: &[String],
-    block: &mut parser::Block,
-) -> Result<(), Error> {
+pub fn resolve(globals: &[String], block: &mut parser::Block) -> Result<(), Error> {
     let mut resolver: Resolver = Default::default();
 
     // Scope for static globals only starts, never ends.