Bob/ROADMAP.md

Bob Language Development Roadmap

Current Status

• Basic expressions (arithmetic, comparison, logical)
• Variables and assignment
• Print statements (converted to standard library function)
• Block statements
• Environment/scoping
• Function implementation (COMPLETED)
• Return statements (COMPLETED)
• Closures (COMPLETED)
• Assert function (COMPLETED)
• Standard library infrastructure (COMPLETED)
• First-class functions and higher-order functions (COMPLETED)
• String + number concatenation with smart formatting (COMPLETED)
• String multiplication (COMPLETED)
• Alphanumeric identifiers (COMPLETED)
• Comprehensive testing framework (COMPLETED)

Phase 1: Core Language Features (High Priority)

1. Control Flow

// If statements
if (x > 10) {
    print "big";
} else {
    print "small";
}

// While loops
var i = 0;
while (i < 5) {
    print i;
    i = i + 1;
}

Implementation:

• Add IfStmt and WhileStmt to Statement.h
• Update parser to handle if and while keywords
• Implement control flow in interpreter

2. Logical Operators

// Currently missing: and, or, not operators
if (x > 0 and y < 10) {
    print "valid range";
}

Implementation:

• Add and, or, not operator parsing
• Implement logical operator evaluation in interpreter

3. Better Error Handling

// Current: Basic error messages
// Goal: Line numbers, better context
Error at line 5: Expected ';' after expression
    print 42
         ^

Phase 2: Data Structures (Medium Priority)

4. Arrays/Lists

var numbers = [1, 2, 3, 4];
print numbers[0];  // 1
numbers[1] = 42;

5. Maps/Dictionaries

var person = {"name": "Bob", "age": 25};
print person["name"];
person["city"] = "NYC";

Phase 3: Standard Library (Medium Priority)

6. Additional Built-in Functions

len("hello");           // String length
input("Enter name: ");  // User input
random(1, 100);        // Random numbers
type(42);              // Type checking

7. File I/O

var content = readFile("data.txt");
writeFile("output.txt", "Hello World");

Phase 4: Advanced Features (Lower Priority)

8. Classes & Objects

class Person {
    init(name, age) {
        this.name = name;
        this.age = age;
    }
    
    greet() {
        print "Hello, I'm " + this.name;
    }
}

var bob = Person("Bob", 25);
bob.greet();

9. Modules/Imports

import "math.bob";
import "utils.bob";

10. Type System

// Optional type annotations
fun add(a: number, b: number): number {
    return a + b;
}

Implementation Tips

For Each 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. Test: Create test cases using assert function

Testing Strategy:

// Use the new assert function for comprehensive testing
assert(add(2, 3) == 5, "add(2, 3) should equal 5");
assert(x > 0, "x should be positive");

Recommended Next Steps

1. Add if statements (fundamental control flow)
2. Add while loops (enables iteration)
3. Implement logical operators (and, or, not)
4. Improve error messages (better developer experience)
5. Add arrays (most useful data structure)

Success Metrics

• Can write simple functions
• Can use return statements
• Can use closures
• Has assert function for testing
• Has standard library infrastructure
• Supports first-class functions
• Has comprehensive testing framework
• Can use if/else statements
• Can use while loops
• Can use logical operators
• Can work with arrays
• Can read/write files
• Has good error messages

Resources

• Crafting Interpreters - Excellent resource for language implementation
• Bob's current source code - Your implementation
• Test files - Examples of current functionality

Recent Achievements

Function Implementation (COMPLETED)

• Function declarations with parameters
• Function calls with arguments
• Return statements
• Proper scoping and closures
• Nested function calls

Standard Library (COMPLETED)

• print() function (converted from statement)
• assert() function with custom messages
• Extensible architecture for adding more functions

Testing Framework (COMPLETED)

• Comprehensive test suite using assert
• Tests for all language features
• Proper error handling and execution stopping

Advanced Language Features (COMPLETED)

• First-class functions and higher-order functions
• Function passing as arguments
• Function composition patterns
• Callback patterns and function storage
• String + number concatenation with smart formatting
• String multiplication (string * number, number * string)
• Alphanumeric identifiers support
• Stress testing with 100-parameter functions