1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2015 Andy Wingo <wingo@igalia.com>
;;;
;;; This file is part of GNU Guix.
;;;
;;; GNU Guix is free software; you can redistribute it and/or modify it
;;; under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 3 of the License, or (at
;;; your option) any later version.
;;;
;;; GNU Guix is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (gnu services configuration)
#:use-module (guix packages)
#:use-module (guix records)
#:use-module (guix gexp)
#:autoload (texinfo) (texi-fragment->stexi)
#:autoload (texinfo serialize) (stexi->texi)
#:use-module (ice-9 match)
#:use-module ((srfi srfi-1) #:select (append-map))
#:use-module (srfi srfi-34)
#:use-module (srfi srfi-35)
#:export (configuration-field
configuration-field-name
configuration-missing-field
configuration-field-error
serialize-configuration
define-configuration
validate-configuration
generate-documentation
serialize-field
serialize-string
serialize-name
serialize-space-separated-string-list
space-separated-string-list?
serialize-file-name
file-name?
serialize-boolean
serialize-package))
;;; Commentary:
;;;
;;; Syntax for creating Scheme bindings to complex configuration files.
;;;
;;; Code:
(define-condition-type &configuration-error &error
configuration-error?)
(define (configuration-error message)
(raise (condition (&message (message message))
(&configuration-error))))
(define (configuration-field-error field val)
(configuration-error
(format #f "Invalid value for field ~a: ~s" field val)))
(define (configuration-missing-field kind field)
(configuration-error
(format #f "~a configuration missing required field ~a" kind field)))
(define-record-type* <configuration-field>
configuration-field make-configuration-field configuration-field?
(name configuration-field-name)
(type configuration-field-type)
(getter configuration-field-getter)
(predicate configuration-field-predicate)
(serializer configuration-field-serializer)
(default-value-thunk configuration-field-default-value-thunk)
(documentation configuration-field-documentation))
(define (serialize-configuration config fields)
(for-each (lambda (field)
((configuration-field-serializer field)
(configuration-field-name field)
((configuration-field-getter field) config)))
fields))
(define (validate-configuration config fields)
(for-each (lambda (field)
(let ((val ((configuration-field-getter field) config)))
(unless ((configuration-field-predicate field) val)
(configuration-field-error
(configuration-field-name field) val))))
fields))
(define-syntax define-configuration
(lambda (stx)
(define (id ctx part . parts)
(let ((part (syntax->datum part)))
(datum->syntax
ctx
(match parts
(() part)
(parts (symbol-append part
(syntax->datum (apply id ctx parts))))))))
(syntax-case stx ()
((_ stem (field (field-type def) doc) ...)
(with-syntax (((field-getter ...)
(map (lambda (field)
(id #'stem #'stem #'- field))
#'(field ...)))
((field-predicate ...)
(map (lambda (type)
(id #'stem type #'?))
#'(field-type ...)))
((field-serializer ...)
(map (lambda (type)
(id #'stem #'serialize- type))
#'(field-type ...))))
#`(begin
(define-record-type* #,(id #'stem #'< #'stem #'>)
#,(id #'stem #'% #'stem)
#,(id #'stem #'make- #'stem)
#,(id #'stem #'stem #'?)
(field field-getter (default def))
...)
(define #,(id #'stem #'stem #'-fields)
(list (configuration-field
(name 'field)
(type 'field-type)
(getter field-getter)
(predicate field-predicate)
(serializer field-serializer)
(default-value-thunk (lambda () def))
(documentation doc))
...))
(define-syntax-rule (stem arg (... ...))
(let ((conf (#,(id #'stem #'% #'stem) arg (... ...))))
(validate-configuration conf
#,(id #'stem #'stem #'-fields))
conf))))))))
(define (uglify-field-name field-name)
(let ((str (symbol->string field-name)))
(string-concatenate
(map string-titlecase
(string-split (if (string-suffix? "?" str)
(substring str 0 (1- (string-length str)))
str)
#\-)))))
(define (serialize-field field-name val)
(format #t "~a ~a\n" (uglify-field-name field-name) val))
(define (serialize-package field-name val)
#f)
(define (serialize-string field-name val)
(serialize-field field-name val))
(define (space-separated-string-list? val)
(and (list? val)
(and-map (lambda (x)
(and (string? x) (not (string-index x #\space))))
val)))
(define (serialize-space-separated-string-list field-name val)
(serialize-field field-name (string-join val " ")))
(define (file-name? val)
(and (string? val)
(string-prefix? "/" val)))
(define (serialize-file-name field-name val)
(serialize-string field-name val))
(define (serialize-boolean field-name val)
(serialize-string field-name (if val "yes" "no")))
;; A little helper to make it easier to document all those fields.
(define (generate-documentation documentation documentation-name)
(define (str x) (object->string x))
(define (generate configuration-name)
(match (assq-ref documentation configuration-name)
((fields . sub-documentation)
`((para "Available " (code ,(str configuration-name)) " fields are:")
,@(map
(lambda (f)
(let ((field-name (configuration-field-name f))
(field-type (configuration-field-type f))
(field-docs (cdr (texi-fragment->stexi
(configuration-field-documentation f))))
(default (catch #t
(configuration-field-default-value-thunk f)
(lambda _ '%invalid))))
(define (show-default? val)
(or (string? default) (number? default) (boolean? default)
(and (symbol? val) (not (eq? val '%invalid)))
(and (list? val) (and-map show-default? val))))
`(deftypevr (% (category
(code ,(str configuration-name)) " parameter")
(data-type ,(str field-type))
(name ,(str field-name)))
,@field-docs
,@(if (show-default? default)
`((para "Defaults to " (samp ,(str default)) "."))
'())
,@(append-map
generate
(or (assq-ref sub-documentation field-name) '())))))
fields)))))
(stexi->texi `(*fragment* . ,(generate documentation-name))))
|
