Commit | Line | Data |
---|---|---|
0f2d19dd JB |
1 | ;;; installed-scm-file |
2 | ||
9630e974 | 3 | ;;;; Copyright (C) 1995, 1996, 1998 Free Software Foundation, Inc. |
0f2d19dd JB |
4 | ;;;; |
5 | ;;;; This program is free software; you can redistribute it and/or modify | |
6 | ;;;; it under the terms of the GNU General Public License as published by | |
7 | ;;;; the Free Software Foundation; either version 2, or (at your option) | |
8 | ;;;; any later version. | |
9 | ;;;; | |
10 | ;;;; This program is distributed in the hope that it will be useful, | |
11 | ;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | ;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | ;;;; GNU General Public License for more details. | |
14 | ;;;; | |
15 | ;;;; You should have received a copy of the GNU General Public License | |
16 | ;;;; along with this software; see the file COPYING. If not, write to | |
15328041 JB |
17 | ;;;; the Free Software Foundation, Inc., 59 Temple Place, Suite 330, |
18 | ;;;; Boston, MA 02111-1307 USA | |
0f2d19dd JB |
19 | ;;;; |
20 | ||
21 | \f | |
8bb7330c | 22 | (define-module (ice-9 hcons)) |
0f2d19dd JB |
23 | |
24 | \f | |
25 | ;;; {Eq? hash-consing} | |
26 | ;;; | |
27 | ;;; A hash conser maintains a private universe of pairs s.t. if | |
28 | ;;; two cons calls pass eq? arguments, the pairs returned are eq?. | |
29 | ;;; | |
30 | ;;; A hash conser does not contribute life to the pairs it returns. | |
31 | ;;; | |
32 | ||
33 | (define-public (hashq-cons-hash pair n) | |
34 | (modulo (logxor (hashq (car pair) 4194303) | |
35 | (hashq (cdr pair) 4194303)) | |
36 | n)) | |
37 | ||
38 | (define-public (hashq-cons-assoc key l) | |
048a208e JB |
39 | (and (not (null? l)) |
40 | (or (and (pair? l) ; If not a pair, use its cdr? | |
41 | (pair? (car l)) | |
42 | (pair? (caar l)) | |
43 | (eq? (car key) (caaar l)) | |
44 | (eq? (cdr key) (cdaar l)) | |
45 | (car l)) | |
46 | (hashq-cons-assoc key (cdr l))))) | |
0f2d19dd JB |
47 | |
48 | (define-public (hashq-cons-get-handle table key) | |
49 | (hashx-get-handle hashq-cons-hash hashq-cons-assoc table key #f)) | |
50 | ||
51 | (define-public (hashq-cons-create-handle! table key init) | |
52 | (hashx-create-handle! hashq-cons-hash hashq-cons-assoc table key init)) | |
53 | ||
54 | (define-public (hashq-cons-ref table key) | |
55 | (hashx-ref hashq-cons-hash hashq-cons-assoc table key #f)) | |
56 | ||
57 | (define-public (hashq-cons-set! table key val) | |
58 | (hashx-set! hashq-cons-hash hashq-cons-assoc table key val)) | |
59 | ||
60 | (define-public (hashq-cons table a d) | |
61 | (car (hashq-cons-create-handle! table (cons a d) #f))) | |
62 | ||
63 | (define-public (hashq-conser hash-tab-or-size) | |
64 | (let ((table (if (vector? hash-tab-or-size) | |
65 | hash-tab-or-size | |
66 | (make-doubly-weak-hash-table hash-tab-or-size)))) | |
67 | (lambda (a d) (hashq-cons table a d)))) | |
68 | ||
69 | ||
70 | \f | |
71 | ||
72 | (define-public (make-gc-buffer n) | |
73 | (let ((ring (make-list n #f))) | |
74 | (append! ring ring) | |
75 | (lambda (next) | |
76 | (set-car! ring next) | |
77 | (set! ring (cdr ring)) | |
78 | next))) |