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

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

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.

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

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

(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