LIPS is a Lisp dialect striving for elegant simplicity and performance.

The core is implemented in strict C99 which should make it easy to compile with most compilers. Besides a C compiler and make, LIPS requires libao and readline.

On Debian-derieved these are easily:

apt-get install build-essential libreadline-dev libao-dev

The latest version of LIPS is available from the repository

git clone https://github.com/martinolsen/lips

Compile and test the code:

make clean all run-test

There, this is pretty much all it does right now.

Integers are simple numbers

42
=> 42

Strings are denoted by enclosing double-quotes

"Hello world!"
=> "Hello world!"

Macros are expanded by the reader, just before evaluation.

To indicate an error, simply call ERROR with an identifying symbol:

(ERROR 'MY-ERROR)

To handle errors, define a lambda as *ERROR-HANDLER*:

(LABEL *ERROR-HANDLER*
  (LAMBDA (C) (PRINT "Error!")))

The identifying symbol is passed to the error handler:

(LABEL *ERROR-HANDLER*
  (LAMBDA (C)
    (COND ((EQ C 'MY-ERROR) (PRINT "My bad!")))))

If the error handler returns NIL, the error is treated as not handled.

The UNBOUND-SYMBOL error accurs when a symbol is not bound to a value (defined).