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1 | ;;; srfi-9.scm --- define-record-type |
2 | ||
1b09b607 | 3 | ;; Copyright (C) 2001, 2002, 2006 Free Software Foundation, Inc. |
6be07c52 | 4 | ;; |
73be1d9e MV |
5 | ;; This library is free software; you can redistribute it and/or |
6 | ;; modify it under the terms of the GNU Lesser General Public | |
7 | ;; License as published by the Free Software Foundation; either | |
8 | ;; version 2.1 of the License, or (at your option) any later version. | |
9 | ;; | |
10 | ;; This library is distributed in the hope that it will be useful, | |
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11 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
73be1d9e MV |
13 | ;; Lesser General Public License for more details. |
14 | ;; | |
15 | ;; You should have received a copy of the GNU Lesser General Public | |
16 | ;; License along with this library; if not, write to the Free Software | |
92205699 | 17 | ;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
a6fd89a4 | 18 | |
e1633bf3 MG |
19 | ;;; Commentary: |
20 | ||
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21 | ;; This module exports the syntactic form `define-record-type', which |
22 | ;; is the means for creating record types defined in SRFI-9. | |
23 | ;; | |
24 | ;; The syntax of a record type definition is: | |
25 | ;; | |
26 | ;; <record type definition> | |
27 | ;; -> (define-record-type <type name> | |
28 | ;; (<constructor name> <field tag> ...) | |
29 | ;; <predicate name> | |
30 | ;; <field spec> ...) | |
31 | ;; | |
32 | ;; <field spec> -> (<field tag> <accessor name>) | |
33 | ;; -> (<field tag> <accessor name> <modifier name>) | |
34 | ;; | |
35 | ;; <field tag> -> <identifier> | |
36 | ;; <... name> -> <identifier> | |
37 | ;; | |
38 | ;; Usage example: | |
39 | ;; | |
40 | ;; guile> (use-modules (srfi srfi-9)) | |
41 | ;; guile> (define-record-type :foo (make-foo x) foo? | |
42 | ;; (x get-x) (y get-y set-y!)) | |
43 | ;; guile> (define f (make-foo 1)) | |
44 | ;; guile> f | |
45 | ;; #<:foo x: 1 y: #f> | |
46 | ;; guile> (get-x f) | |
47 | ;; 1 | |
48 | ;; guile> (set-y! f 2) | |
49 | ;; 2 | |
50 | ;; guile> (get-y f) | |
51 | ;; 2 | |
52 | ;; guile> f | |
53 | ;; #<:foo x: 1 y: 2> | |
54 | ;; guile> (foo? f) | |
55 | ;; #t | |
56 | ;; guile> (foo? 1) | |
57 | ;; #f | |
a6fd89a4 | 58 | |
e1633bf3 MG |
59 | ;;; Code: |
60 | ||
1a179b03 MD |
61 | (define-module (srfi srfi-9) |
62 | :export-syntax (define-record-type)) | |
a6fd89a4 | 63 | |
1b2f40b9 MG |
64 | (cond-expand-provide (current-module) '(srfi-9)) |
65 | ||
a6fd89a4 MG |
66 | (define-macro (define-record-type type-name constructor/field-tag |
67 | predicate-name . field-specs) | |
68 | `(begin | |
69 | (define ,type-name | |
70 | (make-record-type ',type-name ',(map car field-specs))) | |
71 | (define ,(car constructor/field-tag) | |
72 | (record-constructor ,type-name ',(cdr constructor/field-tag))) | |
73 | (define ,predicate-name | |
74 | (record-predicate ,type-name)) | |
75 | ,@(map | |
76 | (lambda (spec) | |
77 | (cond | |
78 | ((= (length spec) 2) | |
79 | `(define ,(cadr spec) | |
80 | (record-accessor ,type-name ',(car spec)))) | |
81 | ((= (length spec) 3) | |
82 | `(begin | |
83 | (define ,(cadr spec) | |
84 | (record-accessor ,type-name ',(car spec))) | |
85 | (define ,(caddr spec) | |
86 | (record-modifier ,type-name ',(car spec))))) | |
87 | (else | |
88 | (error "invalid field spec " spec)))) | |
89 | field-specs))) | |
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90 | |
91 | ;;; srfi-9.scm ends here |