;;; static.el --- tools for static evaluation  -*- lexical-binding: t -*-

;; Copyright (C) 1999 Tanaka Akira <akr@jaist.ac.jp>

;; Author: Tanaka Akira <akr@jaist.ac.jp>
;; Keywords: byte compile, evaluation

;; This file is part of APEL (A Portable Emacs Library).

;; This program is free software; you can redistribute it and/or
;; modify it under the terms of the GNU General Public License as
;; published by the Free Software Foundation; either version 2, or (at
;; your option) any later version.

;; This program is distributed in the hope that it will be useful, but
;; WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;; General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Code:

(put 'static-if 'lisp-indent-function 2)
(defmacro static-if (cond then &rest else)
  "Like `if', but evaluate COND at compile time."
  (if (eval cond)
      then
    `(progn ,@ else)))

(put 'static-when 'lisp-indent-function 1)
(defmacro static-when (cond &rest body)
  "Like `when', but evaluate COND at compile time."
  (if (eval cond)
      `(progn ,@ body)))

(put 'static-unless 'lisp-indent-function 1)
(defmacro static-unless (cond &rest body)
  "Like `unless', but evaluate COND at compile time."
  (if (eval cond)
      nil
    `(progn ,@ body)))

(put 'static-condition-case 'lisp-indent-function 2)
(defmacro static-condition-case (var bodyform &rest handlers)
  "Like `condition-case', but evaluate BODYFORM at compile time."
  (eval `(condition-case ,var
             (list (quote quote) ,bodyform)
           ,@
           (mapcar
            (if var
                (lambda (h)
                  `(,(car h)
                    (list (quote funcall)
                          (lambda (,var) ,@ (cdr h))
                          (list (quote quote) ,var))))
              (lambda (h)
                `(,(car h) (quote (progn ,@ (cdr h))))))
            handlers))))

(put 'static-defconst 'lisp-indent-function 'defun)
(defmacro static-defconst (symbol initvalue &optional docstring)
  "Like `defconst', but evaluate INITVALUE at compile time.

The variable SYMBOL can be referred at both compile time and run time."
  (let ((value (eval initvalue)))
    (eval `(defconst ,symbol (quote ,value) ,docstring))
    `(defconst ,symbol (quote ,value) ,docstring)))

(defmacro static-cond (&rest clauses)
  "Like `cond', but evaluate CONDITION part of each clause at compile time."
  (while (and clauses
	      (not (eval (car (car clauses)))))
    (setq clauses (cdr clauses)))
  (if clauses
      (cons 'progn (cdr (car clauses)))))


;;; @ end
;;;

(require 'product)
(product-provide (provide 'static) (require 'apel-ver))

;;; static.el ends here
