# Bob Language Development Roadmap

## Current Status

Bob is a working programming language with a solid foundation. Here's what's currently implemented:

### ✅ **Core Language Features**

#### **Data Types & Variables**
- **Numbers**: Integers, floats, automatic conversion
- **Strings**: Literals, concatenation, multiplication
- **Booleans**: `true`, `false`
- **None**: Null value representation
- **Variables**: Declaration, assignment, scoping
- **Assignment System**: Dual system (statements + expressions for loops)

#### **Operators**
- **Arithmetic**: `+`, `-`, `*`, `/`, `%`
- **Comparison**: `==`, `!=`, `>`, `<`, `>=`, `<=`
- **Logical**: `&&`, `||`, `!` (with short-circuit evaluation)
- **Bitwise**: `&`, `|`, `^`, `<<`, `>>`, `~`
- **Compound Assignment**: `+=`, `-=`, `*=`, `/=`, `%=`, `&=`, `|=`, `^=`, `<<=`, `>>=`
- **Ternary**: `condition ? valueIfTrue : valueIfFalse`

#### **Control Flow**
- **If Statements**: `if`, `else`, `else if` chains
- **While Loops**: Basic, nested, complex conditions
- **For Loops**: All clause variations, nested loops
- **Do-While Loops**: Basic, nested, break/continue support
- **Break/Continue**: Full support in all loop types

#### **Functions**
- **Function Declaration**: `func name(params) { body }`
- **Parameters**: Any number of parameters
- **Return Values**: Explicit and implicit returns
- **Closures**: Lexical scoping with variable capture
- **First-Class Functions**: Functions as values, parameters, return values
- **Anonymous Functions**: `func(params) { body }`
- **Nested Functions**: Functions defined inside other functions
- **Recursion**: Full support including deep recursion
- **Tail Call Optimization**: Trampoline-based optimization to prevent stack overflow

#### **Data Structures**
- **Arrays/Lists**: Full support with indexing, assignment, and built-in functions
- **Maps/Dictionaries**: Full support with key-value pairs and built-in functions
- **Array Operations**: `len()`, indexing, assignment, nested arrays
- **Dictionary Operations**: `keys()`, `values()`, `has()`, indexing, assignment

#### **Standard Library**
- **`print()`**: Output with automatic type conversion
- **`assert()`**: Testing with custom error messages
- **`type()`**: Runtime type checking
- **`toString()`**: Universal string conversion
- **`toNumber()`**: String-to-number conversion
- **`input()`**: User input capability
- **`time()`**: Microsecond precision timing
- **`random()`**: Random number generation (properly seeded)
- **`len()`**: Get length of arrays and strings
- **`keys()`**: Get all keys from dictionaries
- **`values()`**: Get all values from dictionaries
- **`has()`**: Check if key exists in dictionary
- **`eval()`**: Evaluate strings as Bob code
- **`sleep()`**: Pause execution for specified seconds
- **`exit()`**: Terminate program with exit code

#### **Advanced Features**
- **String Operations**: Bidirectional string + number concatenation
- **Number Formatting**: Smart significant digits
- **Memory Management**: Automatic cleanup with shared pointers
- **Error Handling**: Comprehensive error reporting with context
- **Testing Framework**: Built-in assert function
- **Operator Precedence**: Full precedence hierarchy
- **Variable Shadowing**: Proper scoping rules
- **Interactive Mode**: Full REPL with error handling

### **Current Limitations**

#### **Advanced Language Features**
- **No Classes/Objects**: No object-oriented programming
- **No Modules/Imports**: No code organization system
- **No Exception Handling**: No try-catch blocks
- **No Type Annotations**: No static type checking
- **No Generics**: No parametric polymorphism

#### **Standard Library Gaps**
- **No File I/O**: No reading/writing files
- **No Network I/O**: No HTTP or socket operations
- **No Math Library**: No advanced mathematical functions (sqrt, max, min, etc.)
- **No Date/Time**: No date manipulation (except `time()`)
- **No String Processing**: No split, join, toUpper, toLower functions

#### **Development Tools**
- **No Debugger**: No debugging tools
- **No Profiler**: No performance analysis
- **No Package Manager**: No dependency management

## **Future Development Phases**

### **Phase 1: Standard Library Expansion (High Priority)**

#### **File I/O**
```bob
var content = readFile("data.txt");
writeFile("output.txt", "Hello World");
var lines = readLines("config.txt");
```

**Implementation Plan:**
- Add `readFile()` function for reading entire files
- Add `writeFile()` function for writing files
- Add `readLines()` function for reading files line by line
- Add error handling for file operations

#### **Math Library**
```bob
var result = sqrt(16);      // 4.0
var max = max(5, 10, 3);    // 10
var min = min(5, 10, 3);    // 3
var abs = abs(-42);         // 42
```

**Implementation Plan:**
- Add `sqrt()` for square root
- Add `max()` and `min()` for multiple arguments
- Add `abs()` for absolute value
- Add `pow()` for exponentiation
- Add `floor()`, `ceil()`, `round()` for rounding

#### **String Processing**
```bob
var parts = split("a,b,c", ",");  // ["a", "b", "c"]
var joined = join(parts, "-");    // "a-b-c"
var upper = toUpper("hello");     // "HELLO"
var lower = toLower("WORLD");     // "world"
```

**Implementation Plan:**
- Add `split()` for string splitting
- Add `join()` for array joining
- Add `toUpper()` and `toLower()` for case conversion
- Add `trim()` for whitespace removal
- Add `replace()` for string replacement

### **Phase 2: Advanced Language Features (Medium Priority)**

#### **Exception Handling**
```bob
try {
    var result = 10 / 0;
} catch (error) {
    print("Error: " + error);
}
```

**Implementation Plan:**
- Add `try`/`catch` syntax
- Implement exception objects
- Add `throw` statement
- Integrate with existing error system

#### **Object System Foundation**
```bob
// Convert everything to inherit from Object base class
// Enable method calls on all types
// Prepare foundation for classes and modules
```

**Implementation Plan:**
- Unify type system under Object base class
- Convert functions to proper objects
- Enable method calls on all data types
- Update Value union to work with object system

#### **Classes & Objects**
```bob
class Person {
    init(name, age) {
        this.name = name;
        this.age = age;
    }
    
    greet() {
        return "Hello, I'm " + this.name;
    }
}
```

**Implementation Plan:**
- Add `class` keyword and syntax
- Implement constructors with `init()`
- Add method definitions
- Support inheritance

### **Phase 3: Module System (Lower Priority)**

#### **Modules/Imports**
```bob
import "math.bob";
import "utils.bob" as utils;

var result = math.sqrt(16);
var helper = utils.format("Hello");
```

**Implementation Plan:**
- Add `import` statement syntax
- Implement module loading from files
- Support namespace aliases
- Create built-in modules (math, utils, etc.)

### **Phase 4: Development Tools (Lower Priority)**

#### **Debugger**
```bob
debugger;  // Breakpoint
var x = 5;
// Step through code
```

**Implementation Plan:**
- Add `debugger` statement
- Implement breakpoint functionality
- Add step-through debugging
- Create debug console interface

#### **Profiler**
```bob
// Built-in performance analysis
// Function call timing
// Memory usage tracking
```

**Implementation Plan:**
- Add performance measurement functions
- Track function call times
- Monitor memory usage
- Generate performance reports

## **Implementation Guidelines**

### **For Each New Feature:**
1. **Lexer**: Add new tokens if needed
2. **Parser**: Add new expression/statement types
3. **AST**: Define new node types
4. **Interpreter**: Implement evaluation logic
5. **Testing**: Create comprehensive test cases

### **Testing Strategy:**
```bob
// Use the built-in assert function for testing
assert(add(2, 3) == 5, "add(2, 3) should equal 5");
assert(len([1, 2, 3]) == 3, "Array length should be 3");
assert(has({"a": 1}, "a"), "Dictionary should have key 'a'");
```

### **Code Quality Standards:**
- **Comprehensive Testing**: Every feature needs test coverage
- **Error Handling**: Graceful error messages with context
- **Documentation**: Update language reference
- **Performance**: Consider memory and speed implications
- **Professional Code**: Clean, maintainable, production-ready

## **Success Metrics**

### **Completed ✅**
- [x] Core language syntax and semantics
- [x] All basic operators and expressions
- [x] Control flow statements
- [x] Functions and closures
- [x] Tail call optimization
- [x] Arrays and dictionaries
- [x] Standard library basics
- [x] Random number generation
- [x] Interactive REPL
- [x] Testing framework
- [x] Comprehensive error handling
- [x] Memory management
- [x] Assignment system design
- [x] Code quality improvements

### **In Progress 🔄**
- [ ] File I/O implementation
- [ ] Math library functions
- [ ] String processing functions

### **Planned 📋**
- [ ] Exception handling system
- [ ] Object system foundation
- [ ] Classes and objects
- [ ] Module system
- [ ] Development tools

## **Resources**

- **[BOB_LANGUAGE_REFERENCE.md](BOB_LANGUAGE_REFERENCE.md)** - Complete language documentation
- **[test_bob_language.bob](test_bob_language.bob)** - Comprehensive test suite
- **[Crafting Interpreters](https://craftinginterpreters.com/)** - Excellent resource for language implementation

## **Recent Major Achievements**

### **Data Structures Implementation**
- Full array support with indexing and assignment
- Complete dictionary system with key-value operations
- Built-in functions: `len()`, `keys()`, `values()`, `has()`
- Nested data structures support

### **Standard Library Expansion**
- `random()` function with proper seeding
- `eval()` for dynamic code execution
- `sleep()` for timing control
- `exit()` for program termination

### **Code Quality Improvements**
- Professional code cleanup
- Performance optimizations
- Consistent error handling
- Memory leak prevention

### **Advanced Language Features**
- Tail call optimization with trampoline system
- Comprehensive error reporting with context
- Interactive REPL with full language support
- Memory management with automatic cleanup

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*Last updated: January 2025*