README.md

CHECK-BNF 8.0.0

What is this?

Macro arguments checker.

Current lisp world

Common Lisp has a true macro. Writing macro means extending the compiler i.e. creating a new language.

Issues

Lack of documentation. Do you want to use LANGUAGE which has no documentation nor BNF?

Proposal

Check-bnf provides a bnf like syntax checker.

It allows you to write macro arguments definition.

It helps the third person to understand your macro.

Usage

(defmacro defun (&whole whole name lambda-list &body body)
  (check-bnf (:whole whole)
    ((name (or symbol setf-name))
     (setf-name ((eql setf) symbol)))
    ((lambda-list list)))
  (list* name lambda-list body))

(defun "name" () :dummy)
;; SYNTAX-ERROR
  Syntax-error in DEFUN

NAME      := [ SYMBOL | SETF-NAME ]
SETF-NAME := ((EQL SETF) SYMBOL)

but "name"

in (DEFUN "name" NIL :DUMMY)

For detail, see spec file.

DOC

You may emb bnf as documentation. Macro DOC allows you to do it by read time evaluation and read time labeling.

(defmacro your-macro (&whole w a)
  #.(check-bnf:doc "Header for your-macro"
      #0=(check-bnf:check-bnf (:whole w)
           ((a symbol))))
  #0#
  `',a)
=> YOUR-MACRO

(documentation 'your-macro 'function)
=> "Header for your-macro
A := SYMBOL
"

DEFBNF

Your macro may have similar syntax e.g. CASE, CCASE, and ECASE. In such cases, you can define global BNF by DEFBNF.

DEFBNF has almost the same syntax as CHECK-BNF but except accepts only one definition and alias is invalid.

Currently <LAMBDA-LIST>, <FUNCTION-TYPE> and <DECLARATION> is provided.

From developer

Product's goal

License

MIT

Developed with

SBCL

Tested with

• SBCL/2.0.9
• CCL/1.12
• ECL/20.4.24 ; Failed.
• CLISP/2.49

Known issue.

CLISP

CLISP say

The Lisp Pretty Printer implementation is not perfect yet.

CHECK-BNF works fine but the printed message is a little bit strange in clisp. For details see spec file.

ECL

Currently CHECK-BNF stop to support ECL due to ECL specific issue.

Installation

quicklisp supported.

* (ql:quickload :check-bnf)