wip

Box return values in LoxError

- Box Return.value in LoxError
- Deref boxed value when assigning to ret
- Box value when constructing Return variants
- Update Cargo.toml edition to 2024 and add nightly toolchain

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rlox"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 [dependencies]

README.org

@@ -2,35 +2,77 @@
 
 * Syntax example:
 #+begin_src
-funzione :: fn(parametro1: Number, parametro2: String): String do
+#this is what a struct delcaration shoul lool like
+Point :: struct{
+      x: Numeric, # btw Numeric in my imagination is a Interface/Trai/Contrato comune to all numberic type
+      y: Numeric,
+}
 
-end
+Point.new :: fn(x:Numeric, y:Numeric) Self:
+          return Point{x,y}
+
+
+Point.sum :: fn(self, other: Point) Self:
+          return Point{x: self.x+other.x, y: self.y+self.y}
+
+
+@(entrypoint)
+main :: fn(parametro1: Numeric, parametro2: String) Void :
+     a := Point.new(67, 420)
+     b := Point.new(42, 47)
+     a = a.sum(b)
+
+     print("par: {},{}", touple(parametro1, parametro2))
+     if parametro1 == 0:
+          print("What do you epexted to happen?")
+     else if parametro1 > 0:
+          for i in range(0,parametro1,1):
+              print("{}", parametro2)
+     else:
+          for i in range(0,parametro1,-1):
+              print("{}", parametro2)
+    range_gen := precook(range, args: [0,parametro1]);
+    match parametro1 is:
+          == 0 =>  print("{}", parametro2),
+          > 0 => forEach(range_gen(1), |x|  print("{}", parametro2)),
+          < 0 =>  forEach(range_gen(-1), |x|  print("{}", parametro2)),
+          _ => panic()
+    match a is:
+          Point(x > 100, y) => print("YEAAA :)"),
+          _ => print("NAIH :(")
 #+end_src
 
 * Planning:
 allora quello che devo fare è:
-** TODO Controllare se ho finito la questione del retourn:labe
+** TODO Controllare se ho finito la questione del return:label
+** TODO Complete the use os source slice inside parser (many node has synthetic source slice or badly wrapped)
 ** TODO implement struct:
 #+begin_src rlox
 Cosa :: struct{
-        field1: Number
+        field1: Numeric
 }
 #+end_src
-*** TODO update lexert
+*** TODO update lexer
 *** TODO update ast
 *** TODO update parser
 ** TODO implement partial function ...
 #+begin_src rlox
-cosa := make(Cosa, feld1: 42)
+cosa := Cosa{feld1: 42}
-function :: fn(self:Cosa, b: Number) -> Number
+function :: fn(self:Cosa, b: Numeric) -> Numeric
 res := function(cosa,44)
 #+end_src
-*** TODO ... to undericlty create method
+*** TODO ... to undirectly create method
 #+begin_src rlox
-res := cosa.function(44)
+res := cosa.function(44);
 #+end_src
 *** TODO ... to make pipeline
 #+begin_src rlox
-res := cosa |> function(44)
+res := cosa |> function(44);
 #+end_src
 ** TODO Understand what is a type system
+** TODO implement struct method:
+#+begin_src rlox
+Cosa.new :: fn(field1: Numeric):Self #+begin_src do
+         return Self{ field1 };
+end;
+#+end_src

examples/test_struct.lox

@@ -0,0 +1,27 @@
+
+Data :: struct {
+    number: Number,
+    string: String,
+    bool: Bool
+};
+
+Data.new :: fn(number: Number, string: String, bool: Bool) -> Self
+do
+    return Self {
+        number: number,
+        string: string,
+        bool: bool
+    };
+end;
+
+Data.function :: fn(
+   self,
+   number: Number,
+   string: String,
+   bool: Bool,)
+   {number == 42} : Nil
+do
+    self.number = number;
+    self.string = string;
+    self.bool = bool;
+end;

rust-toolchain.toml

@@ -0,0 +1,2 @@
+[toolchain]
+channel = "nightly"

src/backend/interpreter.rs

@@ -2,8 +2,9 @@ use crate::{
     backend::environment::EnvironmentStack,
     common::{
         ast::{AstNode, Expr, NodeId},
-        base_value::{BaseValue, NativeFunction, Number, Truthy},
+        base_value::{BaseValue, NativeFunction, Number, Struct, Truthy},
-        lox_result::{runtime_error, LoxError, LoxResult},
+        lox_result::{LoxError, LoxResult, runtime_error},
+        types::Type,
     },
     frontend::{source_registry::SourceSlice, tokens::TokenType},
 };
@@ -32,14 +33,14 @@ impl Interpreter {
         let mut env = EnvironmentStack::new();
         let _ = env.declare(
             "clock".to_string(),
-            BaseValue::NativeFunction(NativeFunction::new(Vec::default(), |_args| {
+            BaseValue::NativeFunction(Box::new(NativeFunction::new(Vec::default(), |_args| {
                 BaseValue::Number(Number::U128(
                     std::time::SystemTime::now()
                         .duration_since(std::time::UNIX_EPOCH)
                         .unwrap()
                         .as_millis(),
                 ))
-            })),
+            }))),
         );
         Self {
             enviorment: env,
@@ -112,7 +113,7 @@ impl Interpreter {
                     match self.eval_expr(body) {
                         Ok(val) => ret = val,
                         Err(LoxError::Return { value, .. }) => {
-                            ret = value;
+                            ret = *value;
                             break;
                         }
                         Err(err) => return Err(err),
@@ -136,7 +137,7 @@ impl Interpreter {
                     match self.eval_expr(body) {
                         Ok(val) => ret = val,
                         Err(LoxError::Return { value, .. }) => {
-                            ret = value;
+                            ret = *value;
                             break;
                         }
                         Err(err) => return Err(err),
@@ -145,6 +146,13 @@ impl Interpreter {
                 }
                 Ok(ret)
             }
+            Expr::Struct { fields } => {
+                let fields: Vec<(String, Type)> = fields
+                    .iter()
+                    .map(|(name, ty)| (name.clone(), ty.clone()))
+                    .collect();
+                Ok(BaseValue::Struct(Box::new(Struct { fields })))
+            }
         };
         // Give location-less runtime errors this node's span.
         match result {
@@ -217,7 +225,7 @@ impl Interpreter {
                 // Execute the function body
                 let result = match self.eval_expr(&func.body) {
                     Ok(value) => Ok(value),
-                    Err(LoxError::Return { value, .. }) => Ok(value),
+                    Err(LoxError::Return { value, .. }) => Ok(*value),
                     Err(err) => Err(err),
                 };
 
@@ -328,7 +336,7 @@ impl Interpreter {
 
                     result = Err(LoxError::Return {
                         source_slice: statement.source_slice.clone(),
-                        value,
+                        value: Box::new(value),
                         return_label: "Hi".to_string(),
                     });
                     break;

src/common/ast.rs

@@ -2,8 +2,11 @@ use crate::{
     common::{base_value::BaseValue, types::Type},
     frontend::{source_registry::SourceSlice, tokens::TokenType},
 };
-use std::fmt::{Debug, Display};
 use std::sync::atomic::{AtomicUsize, Ordering};
+use std::{
+    collections::HashMap,
+    fmt::{Debug, Display},
+};
 
 /// A unique identity for an AST node, assigned once at construction.
 ///
@@ -23,7 +26,7 @@ impl NodeId {
     }
 }
 
-#[derive(Clone, PartialEq)]
+#[derive(Clone, PartialEq, Debug)]
 pub enum Expr {
     Literal {
         value: Box<BaseValue>,
@@ -83,6 +86,9 @@ pub enum Expr {
         increment: Box<AstNode>,
         body: Box<AstNode>,
     },
+    Struct {
+        fields: Box<HashMap<String, Type>>,
+    },
 }
 
 // Implementazione Display per Expr (per debugging)
@@ -164,100 +170,18 @@ impl std::fmt::Display for Expr {
                 "For({} = {} in {}) {{\n{}\n}}",
                 variable.node, condition.node, increment.node, body.node
             ),
+            Expr::Struct { fields } => {
+                let field_strs: Vec<String> = fields
+                    .iter()
+                    .map(|(k, v)| format!("{}: {:?}", k, v))
+                    .collect();
+                write!(f, "Struct {{ {} }}", field_strs.join(", "))
+            }
         }
     }
 }
 
-impl Debug for Expr {
+// Debug is derived on Expr via #[derive(Debug)] above.
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Expr::Literal { value } => write!(f, "{:?} ", value,),
-            Expr::Binary {
-                left,
-                operator,
-                right,
-            } => write!(f, "({:?} {:?} {:?}) ", operator, left.node, right.node,),
-            Expr::Unary { operator, operand } => {
-                write!(f, "(Unary {:?} {:?}) ", operator, operand.node,)
-            }
-            Expr::Grouping { expression } => {
-                write!(f, "(Grouping {:?})", expression.node,)
-            }
-            Expr::Identifier { name } => {
-                write!(f, "(variable {:?})", name,)
-            }
-            Expr::Call { callee, arguments } => write!(
-                f,
-                "Call ({}({}))",
-                callee.node,
-                arguments
-                    .iter()
-                    .map(|arg| arg.node.to_string())
-                    .collect::<Vec<String>>()
-                    .join(", "),
-            ),
-            Expr::Assign { name, value } => {
-                write!(f, "(assign {:?} {:?})", name, value.node,)
-            }
-            Expr::If {
-                condition,
-                then_branch,
-                elif_branches,
-                else_branch,
-            } => {
-                let mut result =
-                    format!("IF ({:?}) {{\n{:?}\n}}", condition.node, then_branch.node,);
-                for (condition, branch) in elif_branches {
-                    result.push_str(&format!(
-                        " ELIF ({:?}) {{\n{:?}\n}}",
-                        condition.node, branch.node,
-                    ));
-                }
-                if let Some(else_branch) = else_branch {
-                    result.push_str(&format!(" ELSE {{\n{:?}\n}}", else_branch.node,));
-                }
-                write!(f, "IfStmt {:?}", result)
-            }
-            Expr::Print { expression } => {
-                write!(f, "Print({:?});", expression.node,)
-            }
-            Expr::VarDeclaration {
-                name,
-                initializer,
-                var_type,
-            } => match initializer {
-                Some(init) => write!(f, "Var({:?}: {:?} = {:?});", name, var_type, init.node,),
-                None => write!(f, "Var({:?}: {:?});", name, var_type,),
-            },
-            Expr::Return { expression, label } => {
-                write!(f, "Return({:?}, {}) ;", expression.node, label,)
-            }
-            Expr::Block { label, statements } => write!(
-                f,
-                "Block [{}] ([\n{:?}\n])",
-                label,
-                statements
-                    .iter()
-                    .map(|stmt| format!("{:?}", stmt.node))
-                    .collect::<Vec<_>>()
-                    .join("\t\t\n"),
-            ),
-            Expr::While { condition, body } => {
-                write!(f, "While({:?}) {{\n{:?}\n}}", condition.node, body.node,)
-            }
-            Expr::For {
-                variable,
-                condition,
-                increment,
-                body,
-            } => write!(
-                f,
-                "For({:?} = {:?} in {:?}) {{\n{:?}\n}} ",
-                variable.node, condition.node, increment.node, body.node,
-            ),
-        }
-    }
-}
 
 #[derive(Clone)]
 pub struct AstNode {

src/common/base_value.rs

@@ -2,8 +2,9 @@ use core::fmt;
 use std::collections::HashMap;
 use std::fmt::Display;
 use std::ops::{Add, Div, Mul, Not, Rem, Sub};
+use std::ptr::fn_addr_eq;
 
-use crate::common::lox_result::{runtime_error, LoxResult};
+use crate::common::lox_result::{LoxResult, runtime_error};
 use crate::common::types::Type;
 use crate::{
     backend::environment::EnvironmentStack, common::ast::AstNode,
@@ -270,9 +271,9 @@ pub enum BaseValue {
     Number(Number),
     Boolean(bool),
     Nil,
-    Function(LoxFunction),
+    Function(Box<LoxFunction>),
-    NativeFunction(NativeFunction),
+    NativeFunction(Box<NativeFunction>),
-    Struct(Struct),
+    Struct(Box<Struct>),
 }
 
 struct Dict {
@@ -284,18 +285,12 @@ struct ReturnValue {
     value: Type,
 }
 
-impl ReturnValue {
-    pub fn new(label: Vec<String>, value: Type) -> Self {
-        Self { label, value }
-    }
-}
-
 impl BaseValue {
     pub fn is_callable(&self) -> bool {
-        match self {
+        matches!(
-            BaseValue::Function(..) | BaseValue::NativeFunction(..) => true,
+            self,
-            _ => false,
+            BaseValue::Function(..) | BaseValue::NativeFunction(..)
-        }
+        )
     }
 }
 
@@ -350,11 +345,16 @@ impl LoxFunction {
     }
 }
 
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone)]
 pub struct NativeFunction {
     pub parameters: Vec<(String, Type)>,
     pub function: fn(&[BaseValue]) -> BaseValue,
 }
+impl PartialEq for NativeFunction {
+    fn eq(&self, other: &Self) -> bool {
+        self.parameters == other.parameters && fn_addr_eq(self.function, other.function)
+    }
+}
 
 impl NativeFunction {
     pub fn new(parameters: Vec<(String, Type)>, function: fn(&[BaseValue]) -> BaseValue) -> Self {
@@ -367,7 +367,7 @@ impl NativeFunction {
 
 #[derive(Debug, Clone, PartialEq)]
 pub struct Struct {
-    pub fields: Vec<(String, BaseValue)>,
+    pub fields: Vec<(String, Type)>,
 }
 
 // Trait implementations for BaseValue

src/common/lox_result.rs

@@ -28,7 +28,7 @@ pub enum LoxError {
     },
     Return {
         source_slice: SourceSlice,
-        value: BaseValue,
+        value: Box<BaseValue>,
         return_label: String,
     },
 }

src/frontend/lexer.rs

@@ -1,5 +1,5 @@
 use crate::common::base_value::{BaseValue, Number};
-use crate::common::lox_result::{lexical_error, LoxError, LoxResult};
+use crate::common::lox_result::{LoxError, LoxResult, lexical_error};
 use crate::frontend::source_registry::{SourceId, SourcePosition, SourceSlice};
 use crate::frontend::tokens::{Token, TokenType};
 
@@ -102,7 +102,7 @@ impl Lexer {
             token_type,
             text,
             SourceSlice::from_positions(
-                self.source_id.clone(),
+                self.source_id,
                 self.start_pos.clone(),
                 self.end_pos.clone(),
             ),
@@ -115,7 +115,7 @@ impl Lexer {
             text,
             Some(literal),
             SourceSlice::from_positions(
-                self.source_id.clone(),
+                self.source_id,
                 self.start_pos.clone(),
                 self.end_pos.clone(),
             ),
@@ -174,7 +174,7 @@ impl Lexer {
                 if self.is_at_end() {
                     return lexical_error(
                         SourceSlice::from_positions(
-                            self.source_id.clone(),
+                            self.source_id,
                             self.start_pos.clone(),
                             self.end_pos.clone(),
                         ),
@@ -190,11 +190,11 @@ impl Lexer {
             (' ', _) | ('\r', _) | ('\t', _) => Ok(None),
             ('\n', _) => Ok(None),
             ('"', _) => self.string(),
-            (c, _) if c.is_digit(10) => self.number(),
+            (c, _) if c.is_ascii_digit() => self.number(),
             (c, _) if c.is_alphanumeric() || c == '_' => self.identifier(),
             _ => Err(LoxError::LexicalError {
                 source_slice: SourceSlice::from_positions(
-                    self.source_id.clone(),
+                    self.source_id,
                     self.start_pos.clone(),
                     self.end_pos.clone(),
                 ),
@@ -210,7 +210,7 @@ impl Lexer {
         if self.is_at_end() {
             return Err(LoxError::LexicalError {
                 source_slice: SourceSlice::from_positions(
-                    self.source_id.clone(),
+                    self.source_id,
                     self.start_pos.clone(),
                     self.end_pos.clone(),
                 ),
@@ -226,14 +226,14 @@ impl Lexer {
 
     fn number(&mut self) -> LoxResult<Option<Token>> {
         // Leggi la parte intera
-        while self.peek().is_digit(10) {
+        while self.peek().is_ascii_digit() {
             self.advance();
         }
 
         // Controlla se c'è una parte decimale
-        let has_decimal = if self.peek() == '.' && self.peek_next().is_digit(10) {
+        let has_decimal = if self.peek() == '.' && self.peek_next().is_ascii_digit() {
             self.advance(); // consuma il '.'
-            while self.peek().is_digit(10) {
+            while self.peek().is_ascii_digit() {
                 self.advance();
             }
             true

src/frontend/parser.rs

@@ -1,7 +1,7 @@
 use crate::{
     common::{
         ast::{AstNode, Expr},
-        base_value::{BaseValue, LoxFunction},
+        base_value::{BaseValue, LoxFunction, Struct},
         lox_result::{parse_error, runtime_error, LoxResult},
         types::Type,
     },
@@ -224,10 +224,31 @@ impl Parser {
     }
 
     fn struct_declaration(&mut self, start_slice: SourceSlice) -> LoxResult<AstNode> {
-        self.consume(TokenType::Struct, "Expect 'struct' after '::'")?;
         self.consume(TokenType::LeftBrace, "Expect '{' after 'struct'")?;
-
+        let mut fields: Vec<(String, Type)> = vec![];
-        todo!()
+        while self.peek().token_type != TokenType::RightBrace {
+            let field_name = self
+                .consume(TokenType::Identifier, "Expect identifier after '{'")?
+                .clone();
+            self.consume(TokenType::Colon, "Expect ':' after field name")?;
+            let field_type = self
+                .consume_type_name("Expect type name after ':'")?
+                .clone();
+            self.consume(TokenType::Comma, "Expect ',' after field type")?;
+            fields.push((field_name.lexeme, Type::Unresolved(field_type)));
+        }
+        let end_slice = self
+            .consume(TokenType::RightBrace, "Expect '}' after struct fields")?
+            .source_slice
+            .clone();
+        let source_slice = SourceSlice::from_source_slices(start_slice, end_slice);
+        Ok(AstNode::new_expression(
+            Expr::Literal {
+                value: Box::new(BaseValue::Struct(Box::new(Struct { fields }))),
+            },
+            source_slice,
+            "Struct".to_string(),
+        ))
     }
 
     fn function_declaration(&mut self, start_slice: SourceSlice) -> LoxResult<AstNode> {
@@ -269,13 +290,13 @@ impl Parser {
         let body = self.statement()?;
         Ok(AstNode::new_expression(
             Expr::Literal {
-                value: Box::new(BaseValue::Function(LoxFunction {
+                value: Box::new(BaseValue::Function(Box::new(LoxFunction {
                     parameters,
                     return_type: Type::Unresolved(return_type.clone()),
                     body,
                     closure: None,
                     guard,
-                })),
+                }))),
             },
             combine_position.clone(),
             return_type.clone(),
@@ -328,11 +349,7 @@ impl Parser {
             start_slice.start_position,
             end_slice.end_position,
         );
-        let label_str = if let Some(label) = label {
+        let label_str = label.unwrap_or_default();
-            label
-        } else {
-            String::default()
-        };
         Ok(AstNode::new_statement(
             Expr::Block {
                 statements: Box::new(statements),
@@ -351,7 +368,7 @@ impl Parser {
         let combined_slice = SourceSlice::from_source_slices(start_slice, end_slice);
         expr.is_statement = true;
         expr.source_slice = combined_slice;
-        return Ok(expr);
+        Ok(expr)
     }
 
     fn return_statement(&mut self, label: Option<String>) -> LoxResult<AstNode> {
@@ -374,11 +391,7 @@ impl Parser {
         let semicolon = self.consume(TokenType::Semicolon, "Expect ';' after return value.")?;
         let end_slice = semicolon.source_slice.clone();
         let combined_slice = SourceSlice::from_source_slices(start_slice, end_slice);
-        let label_str = if let Some(label) = label {
+        let label_str = label.unwrap_or_default();
-            label
-        } else {
-            String::default()
-        };
         Ok(AstNode::new_statement(
             Expr::Return {
                 expression: Box::new(expr),
@@ -653,7 +666,7 @@ impl Parser {
         // Estendi il source_slice per includere le parentesi di chiusura
         let end_slice = self.previous().source_slice.end_position.clone();
         let full_slice = SourceSlice {
-            source_id: callee.source_slice.source_id.clone(),
+            source_id: callee.source_slice.source_id,
             start_position: start_slice.clone(),
             end_position: end_slice.clone(),
         };
@@ -779,7 +792,7 @@ impl Parser {
 
     fn peek(&self) -> &Token {
         if self.is_at_end() {
-            &self.tokens.last().unwrap()
+            self.tokens.last().unwrap()
         } else {
             &self.tokens[self.current]
         }
@@ -787,7 +800,7 @@ impl Parser {
 
     fn peek_next(&self) -> &Token {
         if self.is_at_end() {
-            &self.peek()
+            self.peek()
         } else {
             &self.tokens[self.current + 1]
         }
@@ -806,7 +819,7 @@ impl Parser {
             self.advance();
             Ok(self.previous())
         } else {
-            return parse_error(self.peek().source_slice.clone(), message);
+            parse_error(self.peek().source_slice.clone(), message)
         }
     }
 

src/frontend/source_registry.rs

@@ -4,7 +4,7 @@ use std::{
     io::ErrorKind,
 };
 
-use crate::common::lox_result::{io_error, LoxResult};
+use crate::common::lox_result::{LoxResult, io_error};
 
 pub struct SourceRegistry {
     pub sources: Vec<SourceFile>,
@@ -226,3 +226,9 @@ impl SourceRegistry {
         line_of_code
     }
 }
+
+impl Default for SourceRegistry {
+    fn default() -> Self {
+        Self::new()
+    }
+}

src/frontend/tokens.rs

@@ -5,6 +5,9 @@ use crate::{common::base_value::BaseValue, frontend::source_registry::SourceSlic
 #[derive(Debug, Clone, PartialEq)]
 pub enum TokenType {
     // Single character tokens
+    Space,
+    Tab,
+    NewLine,
     LeftParen,
     RightParen,
     LeftBrace,
@@ -70,6 +73,9 @@ pub enum TokenType {
 impl fmt::Display for TokenType {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
+            TokenType::Space => write!(f, "/s"),
+            TokenType::Tab => write!(f, "/t"),
+            TokenType::NewLine => write!(f, "/n"),
             TokenType::Bang => write!(f, "!"),
             TokenType::BangEqual => write!(f, "!="),
             TokenType::Equal => write!(f, "="),

src/logging/display_ast.rs

@@ -117,7 +117,7 @@ impl PrettyContext {
     }
 
     fn should_truncate(&self) -> bool {
-        self.config.max_depth.map_or(false, |max| self.depth >= max)
+        self.config.max_depth.is_some_and(|max| self.depth >= max)
     }
 }
 
@@ -414,6 +414,27 @@ impl PrettyPrint for Expr {
                 body.pretty_print(&ctx.child_context(true), f)?;
                 writeln!(f, "{}}}", ctx.child_context(true).indent())
             }
+            Expr::Struct { fields } => {
+                if ctx.config.compact {
+                    let field_strs: Vec<String> = fields
+                        .iter()
+                        .map(|(k, v)| format!("{}: {:?}", k, v))
+                        .collect();
+                    write!(f, "struct {{ {} }}", field_strs.join(", "))
+                } else {
+                    writeln!(f, "{}Struct {{", indent)?;
+                    for (name, ty) in fields.iter() {
+                        writeln!(
+                            f,
+                            "{}{}: {:?},",
+                            ctx.child_context(false).indent(),
+                            name,
+                            ty
+                        )?;
+                    }
+                    write!(f, "{}}}", indent)
+                }
+            }
         }
     }
 }

src/logging/display_token.rs

@@ -102,17 +102,17 @@ impl Token {
                 }
                 None => {
                     if config.colored {
-                        format!("{}", self.colored_type())
+                        self.colored_type().to_string()
                     } else {
-                        format!("{}", self.token_type_symbol())
+                        self.token_type_symbol().to_string()
                     }
                 }
             }
         } else {
             if config.colored {
-                format!("{}", self.colored_type())
+                self.colored_type().to_string()
             } else {
-                format!("{}", self.token_type_symbol())
+                self.token_type_symbol().to_string()
             }
         }
     }
@@ -148,6 +148,9 @@ impl Token {
 
     fn token_type_symbol(&self) -> &'static str {
         match self.token_type {
+            TokenType::Space => "SPC",
+            TokenType::Tab => "TAB",
+            TokenType::NewLine => "NEL",
             TokenType::LeftParen => "(",
             TokenType::RightParen => ")",
             TokenType::LeftBrace => "{",
@@ -256,7 +259,9 @@ impl Token {
             | TokenType::Dot
             | TokenType::Semicolon => ("\x1b[37m", self.token_type_symbol()),
             TokenType::StartBlock | TokenType::EndBlock => ("\x1b[35m", self.token_type_symbol()),
-            TokenType::Eof => ("\x1b[33m", self.token_type_symbol()),
+            TokenType::Eof | TokenType::Space | TokenType::Tab | TokenType::NewLine => {
+                ("\x1b[33m", self.token_type_symbol())
+            }
             TokenType::In => ("\x1b[36m", self.token_type_symbol()),
         };
 

src/main.rs

@@ -33,12 +33,10 @@ fn main() -> LoxResult<()> {
     println!("running {file_path:?}");
     let mut lox = LoxInterpreter::new(debug);
 
-    let res = match file_path {
+    match file_path {
         Some(path) => lox.run_file(&path, stage),
         None => lox.run_prompt(stage),
-    };
+    }
-
-    res
 }
 
 fn parse_args(args: &[String]) -> (ExecutionStage, Option<String>, bool) {
@@ -140,13 +138,12 @@ impl LoxInterpreter {
 
                     match self.source_registry.add_source_string(line.to_string()) {
                         Ok(source_id) => {
-                            match self.process_source(source_id, stage, self.debug) {
+                            if let Ok(result) = self.process_source(source_id, stage, self.debug) {
-                                Ok(result) => match stage {
+                                match stage {
                                     ExecutionStage::Tokens => println!("Tokens: {}", result),
                                     ExecutionStage::Ast => println!("AST: {}", result),
                                     ExecutionStage::Full => println!("Result: {}", result),
-                                },
+                                }
-                                Err(_) => {} // Errore già stampato in process_source
                             }
                         }
                         Err(e) => eprintln!("Error: {}", e),
@@ -167,9 +164,8 @@ impl LoxInterpreter {
         let source_content = self.source_registry.get_by_id(source_id).content.clone();
         let mut lexer = Lexer::new(source_content, source_id);
 
-        lexer.scans_tokens().or_else(|err| {
+        lexer.scans_tokens().inspect_err(|err| {
             err.print_with_context(&self.source_registry);
-            Err(err)
         })
     }
 
@@ -177,9 +173,8 @@ impl LoxInterpreter {
     fn parse_to_ast(&self, source_id: SourceId) -> LoxResult<Vec<AstNode>> {
         let tokens = self.tokenize(source_id)?;
 
-        Parser::new(tokens).parse().or_else(|err| {
+        Parser::new(tokens).parse().inspect_err(|err| {
             err.print_with_context(&self.source_registry);
-            Err(err)
         })
     }
 
@@ -196,9 +191,8 @@ impl LoxInterpreter {
             if debug {
                 println!("Executing statement {}: {:?}", index, stmt);
             }
-            result = Some(interpreter.evaluate(stmt.clone()).or_else(|err| {
+            result = Some(interpreter.evaluate(stmt.clone()).inspect_err(|err| {
                 err.print_with_context(&self.source_registry);
-                Err(err)
             })?);
         }
 
@@ -231,9 +225,8 @@ impl LoxInterpreter {
         let mut lexer = Lexer::new(source_content, source_id);
 
         // Stage 1: Tokenization
-        let tokens = lexer.scans_tokens().or_else(|err| {
+        let tokens = lexer.scans_tokens().inspect_err(|err| {
             err.print_with_context(&self.source_registry);
-            Err(err)
         })?;
 
         // Se debug è attivo, mostra sempre i tokens
@@ -247,9 +240,8 @@ impl LoxInterpreter {
         }
 
         // Stage 2: Parsing
-        let ast = Parser::new(tokens).parse().or_else(|err| {
+        let ast = Parser::new(tokens).parse().inspect_err(|err| {
             err.print_with_context(&self.source_registry);
-            Err(err)
         })?;
 
         // Se debug è attivo, mostra sempre l'AST
@@ -272,9 +264,8 @@ impl LoxInterpreter {
             if debug {
                 println!("Executing statement {}: {:?}", index, stmt);
             }
-            result = Some(interpreter.evaluate(stmt.clone()).or_else(|err| {
+            result = Some(interpreter.evaluate(stmt.clone()).inspect_err(|err| {
                 err.print_with_context(&self.source_registry);
-                Err(err)
             })?);
         }
 
@@ -295,7 +286,7 @@ fn format_tokens(tokens: &[crate::frontend::tokens::Token]) -> String {
 }
 
 fn format_ast(ast: &[AstNode]) -> String {
-    use crate::logging::display_ast::{pretty_print_with_config, PrettyConfig};
+    use crate::logging::display_ast::{PrettyConfig, pretty_print_with_config};
 
     let config = PrettyConfig {
         indent: "  ".to_string(),

src/middleend/scope_stack.rs

@@ -52,12 +52,12 @@ impl<T> ScopeStack<T> {
 
     /// Update an existing binding in the innermost scope (no-op if absent).
     pub fn set_local(&mut self, name: &str, state: T) {
-        if let Some(scope) = self.scopes.last_mut() {
+        if let Some(scope) = self.scopes.last_mut()
-            if let Some(slot) = scope.get_mut(name) {
+            && let Some(slot) = scope.get_mut(name)
+        {
             *slot = state;
         }
     }
-    }
 
     /// Look up `name` in the innermost scope only.
     pub fn get_local(&self, name: &str) -> Option<&T> {
@@ -68,7 +68,7 @@ impl<T> ScopeStack<T> {
     pub fn declared_in_current(&self, name: &str) -> bool {
         self.scopes
             .last()
-            .map_or(false, |scope| scope.contains_key(name))
+            .is_some_and(|scope| scope.contains_key(name))
     }
 
     /// Distance (in scopes) from the innermost scope to the one declaring

src/middleend/visit_ast.rs

@@ -136,6 +136,8 @@ pub fn walk_expr<V: Visitor>(visitor: &mut V, expr: &AstNode) -> LoxResult<()> {
             visitor.visit_expr(increment)?;
             visitor.visit_expr(body)
         }
+        // Struct declarations carry only type information, no child expressions.
+        Expr::Struct { .. } => Ok(()),
     }
 }