mapping.lisp - clic - Clic is an command line interactive client for gopher written in Common LISP (HTM) git clone git://bitreich.org/clic/ git://enlrupgkhuxnvlhsf6lc3fziv5h2hhfrinws65d7roiv6bfj7d652fid.onion/clic/ (DIR) Log (DIR) Files (DIR) Refs (DIR) Tags (DIR) README (DIR) LICENSE --- mapping.lisp (2910B) --- 1 ;;;; -*- Mode: lisp; indent-tabs-mode: nil -*- 2 ;;; 3 ;;; mapping.lisp --- An example for mapping Lisp objects to ints. 4 ;;; 5 ;;; Copyright (C) 2007, Luis Oliveira <loliveira@common-lisp.net> 6 ;;; 7 ;;; Permission is hereby granted, free of charge, to any person 8 ;;; obtaining a copy of this software and associated documentation 9 ;;; files (the "Software"), to deal in the Software without 10 ;;; restriction, including without limitation the rights to use, copy, 11 ;;; modify, merge, publish, distribute, sublicense, and/or sell copies 12 ;;; of the Software, and to permit persons to whom the Software is 13 ;;; furnished to do so, subject to the following conditions: 14 ;;; 15 ;;; The above copyright notice and this permission notice shall be 16 ;;; included in all copies or substantial portions of the Software. 17 ;;; 18 ;;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 19 ;;; EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 20 ;;; MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 21 ;;; NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 22 ;;; HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 23 ;;; WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 24 ;;; OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 25 ;;; DEALINGS IN THE SOFTWARE. 26 ;;; 27 28 ;;; This is an example on how to tackle the problem of passing Lisp 29 ;;; object identifiers to foreign code. It is not a great example, 30 ;;; but might be useful nevertheless. 31 ;;; 32 ;;; Requires trivial-garbage: <http://cliki.net/trivial-garbage> 33 34 (defpackage #:cffi-mapping-test 35 (:use #:common-lisp #:cffi #:trivial-garbage) 36 (:export #:run)) 37 38 (in-package #:cffi-mapping-test) 39 40 (define-foreign-type lisp-object-type () 41 ((weakp :initarg :weakp)) 42 (:actual-type :unsigned-int)) 43 44 (define-parse-method lisp-object (&key weak-mapping) 45 (make-instance 'lisp-object-type :weakp weak-mapping)) 46 47 (defvar *regular-hashtable* (make-hash-table)) 48 (defvar *weak-hashtable* (make-weak-hash-table :weakness :value)) 49 (defvar *regular-counter* 0) 50 (defvar *weak-counter* 0) 51 52 (defun increment-counter (value) 53 (mod (1+ value) (expt 2 (* 8 (foreign-type-size :unsigned-int))))) 54 55 (define-modify-macro incf-counter () increment-counter) 56 57 (defmethod translate-to-foreign (value (type lisp-object-type)) 58 (with-slots (weakp) type 59 (let ((id (if weakp 60 (incf-counter *weak-counter*) 61 (incf-counter *regular-counter*))) 62 (ht (if weakp *weak-hashtable* *regular-hashtable*))) 63 (setf (gethash id ht) value) 64 id))) 65 66 (defmethod translate-from-foreign (int (type lisp-object-type)) 67 (with-slots (weakp) type 68 (gethash int (if weakp *weak-hashtable* *regular-hashtable*)))) 69 70 ;;;; Silly example. 71 72 (defctype weak-mapping (lisp-object :weak-mapping t)) 73 74 ;;; (run) => #<FUNCTION (LAMBDA (X)) {11AB46F5}> 75 (defun run () 76 (foreign-funcall "abs" weak-mapping (lambda (x) x) weak-mapping))