pradcoder / lispy

A lisp like language and interpreter based on "Build your own lisp"

Lispy

A lisp built based on "Build your own Lisp" by Daniel Holden.

Lispy in Action

To see Lispy in action use compileLispy.sh (you will first have change permissions for this file).The executable Lispy will be generated. I've written the Bash script to make use of the cc compiler, if you have gcc you can change the initial cc to gcc to compile.

Arithmetic operations are applied to arguments much like how functions in a regular programming language is applied (i.e. Polish notation is used for arithmetic).

Input> (+ 1 1)
2

There are a few example files provided (those ending with lspy) to run these pass the filename as an argument to the executable.

./Lispy stdlib.lspy

The following function to compute the nth Fibonacci number is provided in the stdlib.lspy file (this is currently the standard library of the language).

; Fibonacci
(fun {fib n} {
	select
		{ (== n 0) 0 }
		{ (== n 1) 1 }
		{ otherwise (+ (fib (- n 1)) (fib (- n 2)))}
})

To use this function simply load the stdlib.lspy file and call the function with a number.

Input> fib 3
2

The syntax for Lispy is almost the same as Common-Lisp (look at the .lspy files to understand the syntax). PLEASE NOTE Lispy is very picky about white-space so make sure to get the spacing right!.

Further steps

I'm planning on using what I've done here to implement a completely new language on my own. As you might've noticed Garbage Collection is currently being worked on.

To be implemented

• Native Types
• User Defined Types
• List Literal
• Operating System interaction
• Macros
• Variable Hashtable
• Pool Allocation
• Garbage Collection
• Tail Call Optimisation
• Lexical Scoping
• Static Typing and more....

lispy's Issues

Chapter 10 Segmentation Faults

Fix the builtin functions that were built as an exercise

Debug the len and init functions