ryan77627/guix
1
0
Fork 0
mirror of https://git.in.rschanz.org/ryan77627/guix.git synced 2024-11-07 15:36:20 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions
guix/gnu/services/configuration.scm
Bruno Victal 00a28bc435
services: configuration: Add some commonly used predicates. 
* gnu/services/configuration.scm (list-of-packages?, list-of-symbols?): New
predicate.
* gnu/services/audio.scm (list-of-symbol?): Remove.
* gnu/services/telephony.scm (string-list?): Remove.
(serialize-string-list): Rename to …
(serialize-list-of-strings): … this.
(account-fingerprint-list?, jami-account-list?): Use list-of.
* doc/guix.texi: Update it.

Signed-off-by: Maxim Cournoyer <maxim.cournoyer@gmail.com>
2023-10-07 12:41:06 -04:00

568 lines
22 KiB
Scheme
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2015 Andy Wingo <wingo@igalia.com>
;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
;;; Copyright © 2017, 2018 Clément Lassieur <clement@lassieur.org>
;;; Copyright © 2021 Xinglu Chen <public@yoctocell.xyz>
;;; Copyright © 2021, 2022 Maxim Cournoyer <maxim.cournoyer@gmail.com>
;;; Copyright © 2021 Andrew Tropin <andrew@trop.in>
;;; Copyright © 2022 Maxime Devos <maximedevos@telenet.be>
;;; Copyright © 2023 Bruno Victal <mirai@makinata.eu>
;;;
;;; 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)
#:use-module ((guix utils) #:select (source-properties->location))
#:use-module ((guix diagnostics)
#:select (formatted-message location-file &error-location
warning))
#:use-module ((guix modules) #:select (file-name->module-name))
#:use-module (guix i18n)
#:autoload (texinfo) (texi-fragment->stexi)
#:autoload (texinfo serialize) (stexi->texi)
#:use-module (ice-9 curried-definitions)
#:use-module (ice-9 format)
#:use-module (ice-9 match)
#:use-module (srfi srfi-1)
#:use-module (srfi srfi-26)
#:use-module (srfi srfi-34)
#:use-module (srfi srfi-35)
#:use-module (srfi srfi-171)
#:export (configuration-field
configuration-field-name
configuration-field-type
configuration-missing-field
configuration-field-error
configuration-field-sanitizer
configuration-field-serializer
configuration-field-getter
configuration-field-default-value-thunk
configuration-field-documentation
configuration-error?
define-configuration
define-configuration/no-serialization
no-serialization
empty-serializer?
tfilter-maybe-value
base-transducer
serialize-configuration
define-maybe
define-maybe/no-serialization
%unset-value
maybe-value
maybe-value-set?
generate-documentation
configuration->documentation
empty-serializer
serialize-package
filter-configuration-fields
interpose
list-of
list-of-packages?
list-of-strings?
list-of-symbols?
alist?
serialize-file-like
text-config?
serialize-text-config
generic-serialize-alist-entry
generic-serialize-alist))
;;; 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 loc field value)
(raise (apply
make-compound-condition
(formatted-message (G_ "invalid value ~s for field '~a'")
value field)
(condition (&configuration-error))
(if loc
(list (condition
(&error-location (location loc))))
'()))))
(define (configuration-missing-field kind field)
(configuration-error
(format #f "~a configuration missing required field ~a" kind field)))
(define (configuration-missing-default-value kind field)
(configuration-error
(format #f "The field `~a' of the `~a' configuration record \
does not have a default value" field kind)))
(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)
(sanitizer configuration-field-sanitizer)
(serializer configuration-field-serializer)
(default-value-thunk configuration-field-default-value-thunk)
(documentation configuration-field-documentation))
(define (empty-serializer? field)
"Predicate that checks whether FIELD is exempt from serialization."
(eq? empty-serializer
(configuration-field-serializer field)))
(define (tfilter-maybe-value config)
"Return a transducer for CONFIG that removes all maybe-type fields whose
value is '%unset-marker."
(tfilter (lambda (field)
(let ((field-value ((configuration-field-getter field) config)))
(maybe-value-set? field-value)))))
(define (base-transducer config)
"Return a transducer for CONFIG that calls the serializing procedures only
for fields marked for serialization and whose values are not '%unset-marker."
(compose (tremove empty-serializer?)
;; Only serialize fields whose value isn't '%unset-marker%.
(tfilter-maybe-value config)
(tmap (lambda (field)
((configuration-field-serializer field)
(configuration-field-name field)
((configuration-field-getter field) config))))))
(define (serialize-configuration config fields)
"Return a G-expression that contains the values corresponding to the
FIELDS of CONFIG, a record that has been generated by `define-configuration'.
The G-expression can then be serialized to disk by using something like
`mixed-text-file'."
#~(string-append
#$@(list-transduce (base-transducer config) rcons fields)))
(define-syntax-rule (id ctx parts ...)
"Assemble PARTS into a raw (unhygienic) identifier."
(datum->syntax ctx (symbol-append (syntax->datum parts) ...)))
(define (define-maybe-helper serialize? prefix syn)
(syntax-case syn ()
((_ stem)
(with-syntax
((stem? (id #'stem #'stem #'?))
(maybe-stem? (id #'stem #'maybe- #'stem #'?))
(serialize-stem (if prefix
(id #'stem prefix #'serialize- #'stem)
(id #'stem #'serialize- #'stem)))
(serialize-maybe-stem (if prefix
(id #'stem prefix #'serialize-maybe- #'stem)
(id #'stem #'serialize-maybe- #'stem))))
#`(begin
(define (maybe-stem? val)
(or (not (maybe-value-set? val))
(stem? val)))
#,@(if serialize?
(list #'(define (serialize-maybe-stem field-name val)
(if (stem? val)
(serialize-stem field-name val)
"")))
'()))))))
(define-syntax define-maybe
(lambda (x)
(syntax-case x (no-serialization prefix)
((_ stem (no-serialization))
(define-maybe-helper #f #f #'(_ stem)))
((_ stem (prefix serializer-prefix))
(define-maybe-helper #t #'serializer-prefix #'(_ stem)))
((_ stem)
(define-maybe-helper #t #f #'(_ stem))))))
(define-syntax-rule (define-maybe/no-serialization stem)
(define-maybe stem (no-serialization)))
(define (normalize-field-type+def s)
(syntax-case s ()
((field-type def)
(identifier? #'field-type)
(values #'(field-type def)))
((field-type)
(identifier? #'field-type)
(values #'(field-type %unset-value)))
(field-type
(identifier? #'field-type)
(values #'(field-type %unset-value)))))
(define (define-configuration-helper serialize? serializer-prefix syn)
(define (normalize-extra-args s)
"Extract and normalize arguments following @var{doc}."
(let loop ((s s)
(sanitizer* #f)
(serializer* #f))
(syntax-case s (sanitizer serializer empty-serializer)
(((sanitizer proc) tail ...)
(if sanitizer*
(syntax-violation 'sanitizer
"duplicate entry" #'proc)
(loop #'(tail ...) #'proc serializer*)))
(((serializer proc) tail ...)
(if serializer*
(syntax-violation 'serializer
"duplicate or conflicting entry" #'proc)
(loop #'(tail ...) sanitizer* #'proc)))
((empty-serializer tail ...)
(if serializer*
(syntax-violation 'empty-serializer
"duplicate or conflicting entry" #f)
(loop #'(tail ...) sanitizer* #'empty-serializer)))
(() ; stop condition
(values (list sanitizer* serializer*)))
((proc) ; TODO: deprecated, to be removed.
(not (or sanitizer* serializer*))
(begin
(warning #f (G_ "specifying serializers after documentation is \
deprecated, use (serializer ~a) instead~%") (syntax->datum #'proc))
(values (list #f #'proc)))))))
(syntax-case syn ()
((_ stem (field field-type+def doc extra-args ...) ...)
(with-syntax
((((field-type def) ...)
(map normalize-field-type+def #'(field-type+def ...)))
(((sanitizer* serializer*) ...)
(map normalize-extra-args #'((extra-args ...) ...))))
(with-syntax
(((field-getter ...)
(map (lambda (field)
(id #'stem #'stem #'- field))
#'(field ...)))
((field-predicate ...)
(map (lambda (type)
(id #'stem type #'?))
#'(field-type ...)))
((field-default ...)
(map (match-lambda
((field-type default-value)
default-value))
#'((field-type def) ...)))
((field-sanitizer ...)
#'(sanitizer* ...))
((field-serializer ...)
(map (lambda (type proc)
(and serialize?
(or proc
(if serializer-prefix
(id #'stem serializer-prefix #'serialize- type)
(id #'stem #'serialize- type)))))
#'(field-type ...)
#'(serializer* ...))))
(define (default-field-sanitizer name pred)
;; Define a macro for use as a record field sanitizer, where NAME
;; is the name of the field and PRED is the predicate that tells
;; whether a value is valid for this field.
#`(define-syntax #,(id #'stem #'validate- #'stem #'- name)
(lambda (s)
;; Make sure the given VALUE, for field NAME, passes PRED.
(syntax-case s ()
((_ value)
(with-syntax ((name #'#,name)
(pred #'#,pred)
(loc (datum->syntax #'value
(syntax-source #'value))))
#'(if (pred value)
value
(configuration-field-error
(and=> 'loc source-properties->location)
'name value))))))))
#`(begin
;; Define field validation macros.
#,@(filter-map (lambda (name pred sanitizer)
(if sanitizer
#f
(default-field-sanitizer name pred)))
#'(field ...)
#'(field-predicate ...)
#'(field-sanitizer ...))
(define-record-type* #,(id #'stem #'< #'stem #'>)
stem
#,(id #'stem #'make- #'stem)
#,(id #'stem #'stem #'?)
#,@(map (lambda (name getter def sanitizer)
#`(#,name #,getter
(default #,def)
(sanitize
#,(or sanitizer
(id #'stem
#'validate- #'stem #'- name)))))
#'(field ...)
#'(field-getter ...)
#'(field-default ...)
#'(field-sanitizer ...))
(%location #,(id #'stem #'stem #'-source-location)
(default (and=> (current-source-location)
source-properties->location))
(innate)))
(define #,(id #'stem #'stem #'-fields)
(list (configuration-field
(name 'field)
(type 'field-type)
(getter field-getter)
(predicate field-predicate)
(sanitizer
(or field-sanitizer
(id #'stem #'validate- #'stem #'- #'field)))
(serializer field-serializer)
(default-value-thunk
(lambda ()
(if (maybe-value-set? (syntax->datum field-default))
field-default
(configuration-missing-default-value
'#,(id #'stem #'% #'stem) 'field))))
(documentation doc))
...))))))))
(define no-serialization ;syntactic keyword for 'define-configuration'
'(no serialization))
(define-syntax define-configuration
(lambda (s)
(syntax-case s (no-serialization prefix)
((_ stem (field field-type+def doc custom-serializer ...) ...
(no-serialization))
(define-configuration-helper
#f #f #'(_ stem (field field-type+def doc custom-serializer ...)
...)))
((_ stem (field field-type+def doc custom-serializer ...) ...
(prefix serializer-prefix))
(define-configuration-helper
#t #'serializer-prefix #'(_ stem (field field-type+def
doc custom-serializer ...)
...)))
((_ stem (field field-type+def doc custom-serializer ...) ...)
(define-configuration-helper
#t #f #'(_ stem (field field-type+def doc custom-serializer ...)
...))))))
(define-syntax-rule (define-configuration/no-serialization
stem (field field-type+def
doc custom-serializer ...) ...)
(define-configuration stem (field field-type+def
doc custom-serializer ...) ...
(no-serialization)))
(define (empty-serializer field-name val) "")
(define serialize-package empty-serializer)
;; Ideally this should be an implementation detail, but we export it
;; to provide a simpler API that enables unsetting a configuration
;; field that has a maybe type, but also a default value. We give it
;; a value that sticks out to the reader when something goes wrong.
;;
;; An example use-case would be something like a network application
;; that uses a default port, but the field can explicitly be unset to
;; request a random port at startup.
(define %unset-value '%unset-marker%)
(define (maybe-value-set? value)
"Predicate to check whether a 'maybe' value was explicitly provided."
(not (eq? %unset-value value)))
;; Ideally there should be a compiler macro for this predicate, that expands
;; to a conditional that only instantiates the default value when needed.
(define* (maybe-value value #:optional (default #f))
"Returns VALUE, unless it is the unset value, in which case it returns
DEFAULT."
(if (maybe-value-set? value)
value
default))
;; 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 (package->symbol package)
"Return the first symbol name of a package that matches PACKAGE, else #f."
(let* ((module (file-name->module-name
(location-file (package-location package))))
(symbols (filter-map
identity
(module-map (lambda (symbol var)
(and (equal? package (variable-ref var))
symbol))
(resolve-module module)))))
(if (null? symbols)
#f
(first symbols))))
(define (generate configuration-name)
(match (assq-ref documentation configuration-name)
((fields . sub-documentation)
`((deftp (% (category "Data Type") (name ,(str configuration-name)))
(para "Available " (code ,(str configuration-name)) " fields are:")
(table
(% (formatter (asis)))
,@(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? val) (number? val) (boolean? val)
(package? val)
(and (symbol? val) (not (eq? val '%invalid)))
(and (list? val) (and-map show-default? val))))
(define (show-default val)
(cond
((package? val)
(symbol->string (package->symbol val)))
(((list-of package?) val)
(format #f "(~{~a~^ ~})" (map package->symbol val)))
(else (str val))))
`(entry (% (heading
(code ,(str field-name))
,@(if (show-default? default)
`(" (default: "
(code ,(show-default default)) ")")
'())
" (type: " ,(str field-type) ")"))
(para ,@field-docs)
,@(append-map
generate
(or (assq-ref sub-documentation field-name)
'())))))
fields)))))))
(stexi->texi `(*fragment* . ,(generate documentation-name))))
(define (configuration->documentation configuration-symbol)
"Take CONFIGURATION-SYMBOL, the symbol corresponding to the name used when
defining a configuration record with DEFINE-CONFIGURATION, and output the
Texinfo documentation of its fields."
;; This is helper for a simple, straight-forward application of
;; GENERATE-DOCUMENTATION.
(let ((fields-getter (module-ref (current-module)
(symbol-append configuration-symbol
'-fields))))
(display (generate-documentation `((,configuration-symbol ,fields-getter))
configuration-symbol))))
(define* (filter-configuration-fields configuration-fields fields
#:optional negate?)
"Retrieve the fields listed in FIELDS from CONFIGURATION-FIELDS.
If NEGATE? is @code{#t}, retrieve all fields except FIELDS."
(filter (lambda (field)
(let ((member? (member (configuration-field-name field) fields)))
(if (not negate?) member? (not member?))))
configuration-fields))
(define* (interpose ls #:optional (delimiter "\n") (grammar 'infix))
"Same as @code{string-join}, but without join and string, returns a
DELIMITER interposed LS. Support 'infix and 'suffix GRAMMAR values."
(when (not (member grammar '(infix suffix)))
(raise
(formatted-message
(G_ "The GRAMMAR value must be 'infix or 'suffix, but ~a provided.")
grammar)))
(fold-right (lambda (e acc)
(cons e
(if (and (null? acc) (eq? grammar 'infix))
acc
(cons delimiter acc))))
'() ls))
;;;
;;; Commonly used predicates
;;;
(define (list-of pred?)
"Return a procedure that takes a list and check if all the elements of
the list result in @code{#t} when applying PRED? on them."
(lambda (x)
(if (list? x)
(every pred? x)
#f)))
(define list-of-packages?
(list-of package?))
(define list-of-strings?
(list-of string?))
(define list-of-symbols?
(list-of symbol?))
;;;
;;; Special serializers
;;;
(define alist?
(list-of pair?))
(define serialize-file-like empty-serializer)
(define (text-config? config)
(list-of file-like?))
(define (serialize-text-config field-name val)
#~(string-append
#$@(interpose
(map
(lambda (e)
#~(begin
(use-modules (ice-9 rdelim))
(with-fluids ((%default-port-encoding "UTF-8"))
(with-input-from-file #$e read-string))))
val)
"\n" 'suffix)))
(define ((generic-serialize-alist-entry serialize-field) entry)
"Apply the SERIALIZE-FIELD procedure on the field and value of ENTRY."
(match entry
((field . val) (serialize-field field val))))
(define (generic-serialize-alist combine serialize-field fields)
"Generate a configuration from an association list FIELDS.
SERIALIZE-FIELD is a procedure that takes two arguments, it will be
applied on the fields and values of FIELDS using the
@code{generic-serialize-alist-entry} procedure.
COMBINE is a procedure that takes one or more arguments and combines
all the alist entries into one value, @code{string-append} or
@code{append} are usually good candidates for this."
(apply combine
(map (generic-serialize-alist-entry serialize-field) fields)))
Reference in a new issue View git blame Copy permalink