A fresh implementation of Common Lisp
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SICL: A new Common Lisp Implementation

This is the main source code repository for SICL. It contains the compiler, standard library, and documentation.

What is SICL?

SICL is a new implementation of Common Lisp. It is intentionally divided into many implementation-independent modules that are written in a totally or near-totally portable way, so as to allow other implementations to incorporate these modules from SICL, rather than having to maintain their own, perhaps implementation-specific versions.

Quick Start

  1. Make sure you have installed the dependencies:

    • A recent 64-bit version of SBCL
    • The system "concrete-syntax-tree" from Quicklisp
    • The system "eclector", also from Quicklisp
  2. Make sure your SBCL has a 10GB heap by passing --dynamic-space-size 10000 to SBCL when it starts up.

  3. Clone the source with git:

    $ git clone https://github.com/robert-strandh/SICL
    $ cd SICL 
  4. Make sure the top-level directory can be found by ASDF.

  5. Compile the boot system as follows:

    (asdf:load-system :sicl-boot)
  6. Change the package for convenience:

    (in-package #:sicl-boot)
  7. Create an instance of the BOOT class:

    (defparameter *b*
      (let ((sicl-extrinsic-environment::*cache-p* t))
         (make-instance 'boot)))

    Creating the first environment will take a few minutes. In particular, it will seem that it is stuck when loading a few files, especially remf-defmacro.lisp.

  8. Start a REPL:

    (sicl-extrinsic-environment::repl (r4 *b*) (r4 *b*))

Using SICL

  1. Cleavir is an implementation-independent compilation framework for Common Lisp. To use, make sure that you that you are in the SICL directory and load the neccesary packages and file.
(ql:quickload '(cleavir-generate-ast  cleavir-ast-to-hir cleavir-hir-interpreter)) 
(load "Code/Cleavir/Environment/Examples/sbcl.lisp")
  1. Now you can compile Common Lisp expressions like
(cleavir-hir-interpreter:interpret-hir (cleavir-sbcl-environment::compile-cleavir '(lambda ()  (+ 32 10))))


SICL releases are here.

Check the Documentation directory for more information.

Getting Help and Contributing

The SICL community members are usually on various IRC channels. There is now a dedicated channel called #sicl, but discussion can also be found on #lisp, #clasp, and #sicl.

Keep up on SICL by reading the IRC logs

If you want to contribute SICL, please read CONTRIBUTING.md.


SICL is primarily distributed under the terms of the BSD license.

See LICENSE-BSD for more details.