cdancette / lispy

Lisp interpreter in python

Lispy : A lisp interpreter in python

Inspired by Peter Norvig's Lispy http://norvig.com/lispy.html

Usage

Run main.py to enter into the REPL.

You can also run main.py file.lisp to run the file.lisp file. It will run it in the current environment. One current limitation for files is that you have to surround your lisp instructions with (begin expr1 expr2 ...). See in examples/list.lisp.

Features

#Supported types :

integers, floats and booleans (#f, #t keywords)

Supported keywords :

• define
• lambda
• set!
• run : (run test.lisp) runs the file in the current environment
• (defun (f x) (expr)) : shortcut to (define f (lambda (x) (expr)))

Other supported things :

• Closures : try (define add (lambda (x) (lambda (y) (+ x y))))
• comments with syntax (* comment.. *)

TODO

• remove the necessary "begin" that surrounds all code in a file
• Read data stream
• simplified (define f (x) (expr)) instead of other keyword defun
• support string type