[cl-unification-devel] Re: cl-unification - bugfix + extension

[Marco Antoniotti]

Hi

I fixed the bugs you reported.  Thanks a lot for spotting them.
I also clarified the disclaimer and noted that the COPYING file 
contains a Berkeley-style license.

I have not yet added your INTERFACE template.  I am quibbling on the 
name.  I would like to call it an ACCESS template, as INTERFACE is a 
bit overloaded.  How do you feel about it?

Cheers
--
Marco





On May 17, 2005, at 2:52 PM, norman werner wrote:

> Oops - New email-webinterface.
>
>
> I have to apologize.
>
>
> Norman
> file in included and as attachment
>
> ;; Copyright (c) 2005 Norman Werner
> ;; All rights reserved.
>
> ;; Permission is hereby granted, without written agreement and without
> ;; license or royalty fees, to use, copy, modify, and distribute this
> ;; software and its documentation for any purpose, provided that the
> ;; above copyright notice and the following two paragraphs appear in 
> all
> ;; copies of this software.
>
> ;; IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE TO ANY PARTY FOR DIRECT,
> ;; INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT 
> OF
> ;; THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE 
> AUTHOR(S),
> ;; HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
>
> ;; THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES,
> ;; INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
> ;; MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
> ;; PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE AUTHOR(S) HAVE NO
> ;; OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, 
> OR
> ;; MODIFICATIONS.
>
>
>
> ;;MOTIVATION:
> ;;When something is specified by its interface we dont want to restrict
> ;;the unifier to a certain implementation.
>
> ;;eg. A tree may be specified by the functions (get-node-value ..) and 
> (get-leafs ...).
> ;;But a tree maybe implemented as a list, a structure or a clos-bject.
>
> ;;Therfore a interface-template is provided which is usefull on its 
> own and
> ;;which may be used to implement other templates.
>
>
> ;;IMPLEMENTATION:
> ;;the following implementation tries to imitate the style of
> ;;the original library. Only little testing was done.
>
>
> ;;this is not rocket-science!
> (in-package "CL.EXT.DACF.UNIFICATION")
>
> (defclass interface-template (type-template) ())
>
> (defgeneric interface-template-p (x)
>   (:method ((x interface-template)) t)
>   (:method ((x t)) nil))
>
> ;;SYNTAX:
> ;;#T(interface read1 var1 read2 var2 ...)
> (defmethod make-template ((kind (eql 'interface)) (spec cons))
>   (declare (ignore kind))
>   (make-instance 'interface-template  :spec (rest spec)))
>
> (defun pairify (list)
>   "groups list into a list of pairs"
>   ;;I don't know how to use loop - so you may want to fix this
>   (cond
>    ((null list) ())
>    ((= (length list) 1) (error "invalid template-spec"))
>    ( t (cons (list (first list) (second list)) (pairify (cddr 
> list))))))
>
> (defmethod collect-template-vars ((template interface-template))
>   (mapcan #'(lambda (l) (destructuring-bind (reader var) l
> 			  (assert (or (symbolp reader)
> 				      (functionp reader)))
> 			  (collect-template-vars var)))
> 	  (pairify (template-spec template))))
>
> ;;;I basically copied this from the unifier-method of structure-objects
> (defmethod unify ((a t) (b interface-template) &optional (env 
> (make-empty-environment)))
>   (if (template-spec b)
>       (loop for (reader value-template) on (template-spec b) by #'cddr
> 	    ;;FIXME/TODO: do we want to catch errors from (funcall reader a) 
> ??
> 	    for mgu = (unify (funcall reader a) value-template env)
> 	    then (unify (funcall reader a) value-template mgu)
> 	    finally (return mgu))
>     env))
>
> (defmethod unify ((b interface-template) (a t)  &optional (env 
> (make-empty-environment)))
>   (unify a b))
>
>
> ;;PROBLEMS:
> ;;(setf e (unify '(1 2 3) #T(interface first ?x)))
> ;; won't work because
> ;; other method are more specific:
>
> ;;(defmethod unify ((a list) (b template) &optional (env 
> (make-empty-environment)))
> ;;  (declare (ignore env))
> ;;  (error 'unification-failure
> ;;         :format-control "Cannot unify a list with a non-list 
> template: ~S ~S."
> ;;         :format-arguments (list a b)))
>
> ;; this applies of yourse also for other usages.
>
> ;; code was tested with the following shortcircuit:
> ;;(defmethod unify ((a list) (b interface-template) &optional (env 
> (make-empty-environment)))
> ;;  (if (template-spec b)
> ;;      (loop for (reader value-template) on (template-spec b) by 
> #'cddr
> ;;	    for mgu = (unify (funcall reader a) value-template env)
> ;;	    then (unify (funcall reader a) value-template mgu)
> ;;	    finally (return mgu))
> ;;    env))
> ;;
>
>
>
>
> ;; Questions / Remarks / BUGS:
>
> ;; Examples in the Documentation for matching of structures and 
> objects doesn't work ?!
> ;; -> Documentation-Bug?
>
> ;; Description of Number-template in the doc is incorrect:
> ;; <quote>
> ;; The NUMBER-TEMPLATE class denotes those object that are used to 
> unify against a VECTOR.
> ;; </quote> ?!
>
> ;; Is a Facility / Documentation for extending the syntax nessecary 
> (hash-tables, streams,
> ;; closures there is a plethora of built-ins in CL) ?!
>
> ;; You mention in the doc that the license isn't settled yet.
> ;; I consider this a critical bug.
>
> ;; maybe 'match' should be renamed to with-match or something else, to 
> make clear that
> ;; new bindings are introduced?!
>
> ;; The following form:
> ;; (unify '(foo ?x 42) '(foo baz ?x))
> ;; will unify despite your documentation and common
> ;; practice.
>
> ;;This should fix it:
> (defmethod unify ((a symbol) (b number)  &optional (env 
> (make-empty-environment)))
>   (cond ((variable-any-p a) env)
>         ((variablep a) (var-unify a b env))
>         (t (error 'unification-failure
>                   :format-control "Cannot unify a number ~S with a 
> symbol ~S."
>                   :format-arguments (list b a)))))
>
> (defmethod unify ((b number) (a symbol)   &optional (env 
> (make-empty-environment)))
>   (unify a b env))
>
>
> ;;(unify '(?x ?x) '("hase" "dodo"))
> ;; unifies despite common practice.
>
> ;; I changed the defmethods
> ;; (defmethod unify ((a symbol) (b string) &optional (env 
> (make-empty-environment)))
> ;;   (cond ((variable-any-p a) env)
> ;;         ((variablep a) (extend-environment a b env))
> ;;         (t (error 'unification-failure
> ;;              :format-control "Cannot unify a symbol with a string: 
> ~S ~S."
> ;;              :format-arguments (list a b)))))
>
>
> ;; (defmethod unify ((b string) (a symbol) &optional (env 
> (make-empty-environment)))
> ;;   (cond ((variable-any-p a) env)
> ;;         ((variablep a) (extend-environment a b env))
> ;;         (t (error 'unification-failure
> ;;                   :format-control "Cannot unify a string with a 
> symbol: ~S ~S."
> ;;                   :format-arguments (list b a)))))
>
> ;;to
>
> (defmethod unify ((a symbol) (b string) &optional (env 
> (make-empty-environment)))
>   (cond ((variable-any-p a) env)
>         ((variablep a) (var-unify a b env))
>         (t (error 'unification-failure
>              :format-control "Cannot unify  symbol with a string: ~S 
> ~S."
>              :format-arguments (list a b)))))
>
>
> (defmethod unify ((b string) (a symbol) &optional (env 
> (make-empty-environment)))
>   (unify a b env))
>
> __________________________________________________________
> Mit WEB.DE FreePhone mit hoechster Qualitaet ab 0 Ct./Min.
> weltweit telefonieren! 
> http://freephone.web.de/?mc=021201<norman-contributes.lisp>
--
Marco Antoniotti					http://bioinformatics.nyu.edu
NYU Courant Bioinformatics Group		tel. +1 - 212 - 998 3488
715 Broadway 10th FL				fax. +1 - 212 - 998 3484
New York, NY, 10003, U.S.A.