tutorials or introductions to writing a simple scripting language?

Introduction to Scripting Languages

Scripting languages are designed for automating tasks and creating interactive applications. They are generally interpreted rather than compiled, making them easier to learn and use.

Why Learn to Write a Scripting Language?

Creating your own scripting language can provide valuable insights into:

• Computer science fundamentals
• Language design principles
• Compiler and interpreter design
• Customizable tools and automation

Steps to Creating a Simple Scripting Language

1. Define the Language’s Syntax

• Determine the basic building blocks like keywords, operators, and data types.
• Create a grammar that specifies the language’s structure.

2. Design the Interpreter

• Develop a program that reads and understands your language’s syntax.
• Implement a parser to break down the script into meaningful components.

3. Implement Functionality

• Define the language’s standard library and functions.
• Implement basic operations such as arithmetic, string manipulation, and input/output.

4. Test and Refine

• Write test cases to validate your language’s functionality.
• Iterate and refine based on feedback and identified limitations.

Recommended Resources

Online Tutorials

• Crafting Interpreters (Comprehensive guide to building an interpreter)
• Build Your Own Programming Language (YouTube Series)

Books

Example: A Simple Calculator Language

Syntax

The language uses a simple infix notation for arithmetic expressions.

expression = number | expression operator expression
operator = '+' | '-' | '*' | '/'
number = integer

Interpreter (Python)

def evaluate(expression):
    if isinstance(expression, int):
        return expression
    else:
        op = expression[1]
        left = evaluate(expression[0])
        right = evaluate(expression[2])
        if op == '+':
            return left + right
        elif op == '-':
            return left - right
        elif op == '*':
            return left * right
        elif op == '/':
            return left / right

Usage

>>> evaluate([2, '+', 3])
5
>>> evaluate([5, '*', [2, '-', 1]])
5

Conclusion

Creating your own scripting language is a rewarding journey that deepens your understanding of computer science principles. By leveraging available resources and following a structured approach, you can build a functional language tailored to your specific needs.