Dropbear Programming Language

A Lisp-inspired programming language built in JavaScript with a focus on clean architecture, and extensibility. Dropbear demonstrates modern language implementation techniques including lexical analysis, recursive descent parsing, and tree-walking interpretation.

Features

Mathematical Operations

• Arithmetic: add, subtract, multiply, divide, modulo
• Comparison: max, min functions for finding highest/lowest values
• Constants: Built-in pi constant
• Flexible Arguments: Most math functions accept variable numbers of arguments

Data Types

• Numbers: Integer support with multi-digit parsing
• Strings: Quoted string literals with whitespace handling
• Identifiers: Variable names and function calls
• Expressions: Nested function calls and complex expressions

Language Features

• Lisp-like Syntax: Parenthesized prefix notation
• REPL Interface: Interactive command-line interface with colored output
• File Execution: Run .dbr files directly from command line
• Whitespace Insensitive: Flexible spacing and formatting
• Error Handling: Comprehensive error messages for invalid syntax

Architecture

• Lexer: Advanced tokenization with character classification
• Parser: Recursive descent parsing with AST generation
• Evaluator: Tree-walking interpreter with environment management
• Standard Library: Built-in functions and constants
• Extensible: Framework for special forms and custom syntax

Getting Started

Installation

# Clone the repository
git clone <your-repo-url>
cd dropbear

# Install dependencies
npm install

# Make the CLI executable
chmod +x bin/dropbear

Usage

Interactive REPL

npm start
# or
./bin/dropbear

Run a File

./bin/dropbear run examples/example.dbr

Programmatic Usage

const { parseAndEvaluate } = require('./src');

const result = parseAndEvaluate('(add 2 3)');
console.log(result); // 5

Language Examples

Basic Math

(add 2 3)                    ; Returns 5
(multiply 4 5)               ; Returns 20
(subtract 10 3)              ; Returns 7
(divide 15 3)                ; Returns 5
(modulo 17 5)                ; Returns 2

Nested Expressions

(multiply (add 2 2) (subtract 10 5))  ; Returns 20
(add 1 2 3 4 5)                       ; Returns 15
(max 3 7 2 9 1)                       ; Returns 9
(min 5 2 8 1 6)                       ; Returns 1

String Operations

(log "Hello, World!")        ; Prints: Hello, World!
(log "Multiple" "strings")   ; Prints: Multiple strings

Constants

pi                           ; Returns 3.141592653589793

Project Structure

src/
├── index.js                 # Main entry point and public API
├── tokenize.js             # Lexical analysis with maximal munch
├── parse.js                # Recursive descent pa