Get some basic unification up and running
author |
Steve Losh <steve@stevelosh.com> |
date |
Tue, 08 Mar 2016 15:27:47 +0000 |
parents |
(none) |
children |
49191daa42d0 |
;;;; This file was automatically generated by Quickutil.
;;;; See http://quickutil.org for details.
;;;; To regenerate:
;;;; (qtlc:save-utils-as "utils.lisp" :utilities '(:DEFINE-CONSTANT :SET-EQUAL) :ensure-package T :package "BONES.UTILS")
(eval-when (:compile-toplevel :load-toplevel :execute)
(unless (find-package "BONES.UTILS")
(defpackage "BONES.UTILS"
(:documentation "Package that contains Quickutil utility functions.")
(:use #:cl))))
(in-package "BONES.UTILS")
(when (boundp '*utilities*)
(setf *utilities* (union *utilities* '(:DEFINE-CONSTANT :SET-EQUAL))))
(defun %reevaluate-constant (name value test)
(if (not (boundp name))
value
(let ((old (symbol-value name))
(new value))
(if (not (constantp name))
(prog1 new
(cerror "Try to redefine the variable as a constant."
"~@<~S is an already bound non-constant variable ~
whose value is ~S.~:@>" name old))
(if (funcall test old new)
old
(restart-case
(error "~@<~S is an already defined constant whose value ~
~S is not equal to the provided initial value ~S ~
under ~S.~:@>" name old new test)
(ignore ()
:report "Retain the current value."
old)
(continue ()
:report "Try to redefine the constant."
new)))))))
(defmacro define-constant (name initial-value &key (test ''eql) documentation)
"Ensures that the global variable named by `name` is a constant with a value
that is equal under `test` to the result of evaluating `initial-value`. `test` is a
function designator that defaults to `eql`. If `documentation` is given, it
becomes the documentation string of the constant.
Signals an error if `name` is already a bound non-constant variable.
Signals an error if `name` is already a constant variable whose value is not
equal under `test` to result of evaluating `initial-value`."
`(defconstant ,name (%reevaluate-constant ',name ,initial-value ,test)
,@(when documentation `(,documentation))))
(defun set-equal (list1 list2 &key (test #'eql) (key nil keyp))
"Returns true if every element of `list1` matches some element of `list2` and
every element of `list2` matches some element of `list1`. Otherwise returns false."
(let ((keylist1 (if keyp (mapcar key list1) list1))
(keylist2 (if keyp (mapcar key list2) list2)))
(and (dolist (elt keylist1 t)
(or (member elt keylist2 :test test)
(return nil)))
(dolist (elt keylist2 t)
(or (member elt keylist1 :test test)
(return nil))))))
(eval-when (:compile-toplevel :load-toplevel :execute)
(export '(define-constant set-equal)))
;;;; END OF utils.lisp ;;;;