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1 | ;;; installed-scm-file |
2 | ||
9630e974 | 3 | ;;;; Copyright (C) 1995, 1996, 1998 Free Software Foundation, Inc. |
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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 | |
a482f2cc MV |
19 | ;;;; |
20 | ;;;; As a special exception, the Free Software Foundation gives permission | |
21 | ;;;; for additional uses of the text contained in its release of GUILE. | |
22 | ;;;; | |
23 | ;;;; The exception is that, if you link the GUILE library with other files | |
24 | ;;;; to produce an executable, this does not by itself cause the | |
25 | ;;;; resulting executable to be covered by the GNU General Public License. | |
26 | ;;;; Your use of that executable is in no way restricted on account of | |
27 | ;;;; linking the GUILE library code into it. | |
28 | ;;;; | |
29 | ;;;; This exception does not however invalidate any other reasons why | |
30 | ;;;; the executable file might be covered by the GNU General Public License. | |
31 | ;;;; | |
32 | ;;;; This exception applies only to the code released by the | |
33 | ;;;; Free Software Foundation under the name GUILE. If you copy | |
34 | ;;;; code from other Free Software Foundation releases into a copy of | |
35 | ;;;; GUILE, as the General Public License permits, the exception does | |
36 | ;;;; not apply to the code that you add in this way. To avoid misleading | |
37 | ;;;; anyone as to the status of such modified files, you must delete | |
38 | ;;;; this exception notice from them. | |
39 | ;;;; | |
40 | ;;;; If you write modifications of your own for GUILE, it is your choice | |
41 | ;;;; whether to permit this exception to apply to your modifications. | |
42 | ;;;; If you do not wish that, delete this exception notice. | |
0f2d19dd JB |
43 | ;;;; |
44 | ||
45 | \f | |
8bb7330c | 46 | (define-module (ice-9 hcons)) |
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47 | |
48 | \f | |
49 | ;;; {Eq? hash-consing} | |
50 | ;;; | |
51 | ;;; A hash conser maintains a private universe of pairs s.t. if | |
52 | ;;; two cons calls pass eq? arguments, the pairs returned are eq?. | |
53 | ;;; | |
54 | ;;; A hash conser does not contribute life to the pairs it returns. | |
55 | ;;; | |
56 | ||
57 | (define-public (hashq-cons-hash pair n) | |
58 | (modulo (logxor (hashq (car pair) 4194303) | |
59 | (hashq (cdr pair) 4194303)) | |
60 | n)) | |
61 | ||
62 | (define-public (hashq-cons-assoc key l) | |
048a208e JB |
63 | (and (not (null? l)) |
64 | (or (and (pair? l) ; If not a pair, use its cdr? | |
65 | (pair? (car l)) | |
66 | (pair? (caar l)) | |
67 | (eq? (car key) (caaar l)) | |
68 | (eq? (cdr key) (cdaar l)) | |
69 | (car l)) | |
70 | (hashq-cons-assoc key (cdr l))))) | |
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71 | |
72 | (define-public (hashq-cons-get-handle table key) | |
73 | (hashx-get-handle hashq-cons-hash hashq-cons-assoc table key #f)) | |
74 | ||
75 | (define-public (hashq-cons-create-handle! table key init) | |
76 | (hashx-create-handle! hashq-cons-hash hashq-cons-assoc table key init)) | |
77 | ||
78 | (define-public (hashq-cons-ref table key) | |
79 | (hashx-ref hashq-cons-hash hashq-cons-assoc table key #f)) | |
80 | ||
81 | (define-public (hashq-cons-set! table key val) | |
82 | (hashx-set! hashq-cons-hash hashq-cons-assoc table key val)) | |
83 | ||
84 | (define-public (hashq-cons table a d) | |
85 | (car (hashq-cons-create-handle! table (cons a d) #f))) | |
86 | ||
87 | (define-public (hashq-conser hash-tab-or-size) | |
88 | (let ((table (if (vector? hash-tab-or-size) | |
89 | hash-tab-or-size | |
90 | (make-doubly-weak-hash-table hash-tab-or-size)))) | |
91 | (lambda (a d) (hashq-cons table a d)))) | |
92 | ||
93 | ||
94 | \f | |
95 | ||
96 | (define-public (make-gc-buffer n) | |
97 | (let ((ring (make-list n #f))) | |
98 | (append! ring ring) | |
99 | (lambda (next) | |
100 | (set-car! ring next) | |
101 | (set! ring (cdr ring)) | |
102 | next))) |