Toy Language Interpreter

A minimalist Scheme-like programming language interpreter written in Python. This project implements a custom programming language with support for basic arithmetic operations, conditionals, and functional programming concepts.

Features

• Lambda functions and closures
• Basic arithmetic operations (+, -, *, /)
• Comparison operators (<, >, <=, >=)
• Boolean operations (and, or, not)
• Conditional statements (if)
• Local variable bindings
• Comments support
• List data structure

Installation

git clone https://github.com/M-krishna/toy_lang.git
cd toy_lang
python3 main.py

Quick start

; Hello World
(display "Hello, World!")

; Basic arithmetic
(+ 1 2 3)  ; => 6
(* 4 5)    ; => 20

; Lambda functions
(lambda (x) (* x x))

; Conditional statements
(if (> 5 3)
    "yes"
    "no")

; Strings
"Hello World"

Language Features

Arithmetic Operations

• Addition: (+ 1 2 3)
• Subtraction: (- 10 5)
• Multiplication: (* 2 3 4)
• Division: (/ 10 2)

Comparison Operators

• Less than: (< 5 10)
• Greater than: (> 10 5)
• Less than or equal: (<= 5 5)
• Greater than or equal: (>= 10 10)

Boolean Operations

• And: (and #t #f)
• Or: (or #t #f)
• Not: (not #t)

Functions

; Define a function
(lambda (x) (* x x))

; Using begin for multiple expressions
(begin
  (define square (lambda (x) (* x x)))
  (square 5))

List data structure

; An empty list
(list)
()

; A list with single value
(list 1)
(1)

(list "a")
(a)

; A list with multiple values
(list 1 2 3 4 5 6 7 8)
(1 2 3 4 5 6 7 8)

(list "a" "b" "c")
(a b c)

; Nested list
(list 1 (list 2 3) 4 5)
(1 (2 3) 4 5)

; Defining a list
(define my_list (list 1 2 3))
my_list ; (1 2 3)

; Defining a nested list
(define my_list (list 1 2 (list 3 4) 5))
my_list ; (1 2 (3 4) 5)

Functions for list data structure

(car (list 1 2 3)) ; returns 1

(cdr (list 1 2 3)) ; returns (2 3)

Cons for constructing pairs

(cons 1 2) ; (1 . 2)

(cons 1 (cons 2 3)) ; (1 2 . 3)

(cons 1 (list 2 3 4)) ; (1 2 3 4)

(cons (list 1 2) 3) ; ((1 2) . 3)

(define pair1 (cons 10 20))
(define pair2 (cons 30 40))
(define combined (cons pair1 pair2))
combined ; ((10 . 20) . (30 . 40))
(car combined) ; (10 . 20)
(cdr combined) ; (30 . 40)

Development

To set up the development environment:

git clone https://github.com/M-krishna/toy_lang.git
cd toy_lang

Contributing

• Fork the repository
• Create your feature branch (git checkout -b feature/amazing-feature)
• Commit your changes (git commit -m 'Add some amazing feature')
• Push to the branch (git push origin feature/amazing-feature)
• Open a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.