hololisp

hololisp is a lisp-1 bytecode-compiled single-threaded small toy programming language.

Features

hololisp takes inspiration from popular lisp dialects, primarily scheme. It includes bytecode compiler and interpreter, along with tracing garbage collector.

hololisp supports primitive data types:

• Numbers (internally represented as IEEE754 doubles)
• Conses
• Symbols

Language features include:

• Variables
• Closures
• Conditionals
• Builtin forms (+, =, list and others)
• User-defined functions
• C FFI
• Functions with variadic number of arguments
• Macros
• REPL

Compile

make

hololisp is currently tested on arm64 macOS and Linux amd64.

By default, hololisp is compiled in release mode. If you want to compile in debug mode add DEBUG=1 flag to make.

Testing

make test

hololisp testing is divided in two parts: unit testing and system-wide functional testing. Unit testing is done using acutest. System-wide testing is done using small programs located in .sh files found in tests directory.

Code coverage can be collected if non-empty COV flag is passed to make:

make test DEBUG=1 COV=1

Usage

hololisp can be used in three modes: REPL, executing script files, and executing command strings.

To execute script pass its name to the program executable:

hololisp examples/game_of_life.hl

REPL session looks like this:

$ hololisp
hololisp> (define x 100)
x
hololisp> x
100
hololisp> (+ x (* x 100))
10100

To execute command string pass it after -e flag:

$ hololisp -e "(+ 1 2)"
3

Examples

(defmacro (compare pred pivot)
  (list 'lambda (list 'it) (list pred 'it pivot)))

(define (qsort lis)
  (when lis
    (let ((pivot (car lis)) 
          (lis (cdr lis)))
      (append
        (qsort (filter (compare < pivot) lis))
        (list pivot)
        (qsort (filter (compare >= pivot) lis))))))

(print (qsort (list 5 6 2 1 4 5 2 6 3 9 1)))
; (1 1 2 2 3 4 5 5 6 6 9)

Examples can be found in the 'examples' directory.

List of examples:

• Conway's Game of life
• Maze generator using recursive backtracking algorithm
• quicksort