Lox Interpreter

This project is an implementation of the Lox programming language interpreter, following the "Crafting Interpreters" book by Robert Nystrom. The Lox interpreter is written in Java and supports various features of the Lox language, including expressions, statements, functions, classes, and inheritance.

Features

• Expressions: Supports binary, unary, grouping, literal, variable, assignment, logical, call, get, set, super, and this expressions.
• Statements: Supports expression, print, variable, block, if, while, function, return, and class statements.
• Functions: Allows defining and calling functions with parameters.
• Classes: Supports class definitions, inheritance, and method overriding.
• Error Handling: Provides error reporting for syntax and runtime errors.
• REPL: Interactive prompt for executing Lox code line by line.
• Script Execution: Execute Lox scripts from files.

Project Structure

• src/main/java/com/interpreter/lox: Contains the main source code for the Lox interpreter.
  • Expr.java: Defines the abstract syntax tree (AST) for expressions.
  • Stmt.java: Defines the AST for statements.
  • Lox.java: Entry point for the interpreter.
  • LoxCallable.java: Interface for callable objects (functions and classes).
  • Return.java: Exception class for handling return statements.
  • Parser.java: Parses tokens into an AST.
  • RuntimeError.java: Exception class for runtime errors.
  • Interpreter.java: Evaluates the AST and executes the code.
  • Resolver.java: Resolves variable and function scopes.
  • LoxInstance.java: Represents instances of Lox classes.
  • LoxClass.java: Represents Lox classes.
  • Scanner.java: Scans source code into tokens.
  • Environment.java: Manages variable scopes.
  • Token.java: Represents tokens.
  • LoxFunction.java: Represents Lox functions.
  • TokenType.java: Enum for token types.
  • AstPrinter.java: Utility for printing the AST.
• src/main/java/com/interpreter/tool: Contains tools for generating AST classes.
  • GenerateAst.java: Tool for generating AST classes.

Getting Started

Prerequisites

• Java Development Kit (JDK) 23 or higher
• Maven

Building the Project

1. Clone the repository:

   git clone https://github.com/Md-Talim/lox-interpreter.git
   cd lox-interpreter

2. Build the project using Maven:

   mvn clean install

Running the Interpreter

To run the interpreter in interactive mode (REPL):

mvn exec:java -Dexec.mainClass="com.interpreter.lox.Lox"

To run a Lox script from a file:

mvn exec:java -Dexec.mainClass="com.interpreter.lox.Lox" -Dexec.args="test.lox"

Example

Here is an example Lox script (test.lox):

class Doughnut {
  cook() {
    print "Fry until golden brown.";
  }
}

class BostonCream < Doughnut {
  cook() {
    super.cook();
    print "Pipe full of custard and coat with chocolate.";
  }
}

BostonCream().cook();

Output

Fry until golden brown.
Pipe full of custard and coat with chocolate.