Builds:

Owl Lisp is a functional dialect of the Scheme programming language. It is mainly based on the applicative subset of the R7RS standard.

You should have make and gcc or clang installed.

To install system-wide to /usr

   $ make
   $ sudo make install

Alternatively you can try it out with

   $ make
   $ cp bin/ol /somewhere/convenient
   $ /somewhere/convenient/ol
   You see a prompt
   >

   bin/ol      - the owl interpreter/compiler
   c/ovm.c     - the virtual machine / shared owl lisp runtime
   owl/*.scm   - implementation of owl repl and compiler
   fasl/*.fasl - bytecode images for bin/vm used during boot
   bin/vm      - plain VM used during boot
   c/ol.c      - combined VM and REPL heap image

Owl can be used either interactively, or to interpret code from files, or compile programs to fasl-images or c-files. The difference between an owl program and a plain script is that the program should just have a function of one argument as the last value, which will be called with the command line argument list when the program is executed.

In addition to being a regular interpreter, owl also tries to make it easy to compile programs for different platforms. Owl programs can be compiled with ol to C-files, which can be compiled to standalone binaries without needing any owl-specific support files or libraries. The C files also work on 32- and 64-bit systems, and compile as such at least on Linux, OpenBSD, and macOS or can be cross-compiled to Windows executables with MinGW.

For example, to build a hello world program:

  $ echo '(lambda (args) (print "Hello, world!"))' > hello.scm
  $ ol -o hello.c hello.scm
  $ gcc -o hello hello.c
  $ ./hello
  Hello, world!

Or simply:

  $ echo '(λ (args) (print "Hello, world!"))' \
     | ol -x c | gcc -x c -o hello - && ./hello

Parts of the compiled programs can be translated to C, instead of being simply fasl-encoded, to increase speed. Using the --native flag compiles most of the bytecode to C, and --usual-suspects compiles typically used functions. To make programs run faster, one can use for example:

  $ ol -O2 -o test.c test.scm && gcc -O2 -o test test.c

For further documentation and updates, see:

https://haltp.org/owl

https://gitlab.com/owl-lisp/owl

https://gitlab.com/owl-lisp