fringe2 files changed, 51 insertions(+)
gnu/packages.scm | 1 +
gnu/services/configuration.scm | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
fringemodified gnu/packages.scm
fringe@@ -49,6 +49,7 @@ (define-module (gnu packages)
#:export (search-patch
search-patches
search-auxiliary-file
+ %distro-root-directory
%patch-path
%auxiliary-files-path
%package-module-path
fringemodified gnu/services/configuration.scm
fringe@@ -25,6 +25,9 @@
;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
(define-module (gnu services configuration)
+ #:use-module (gnu packages)
+ #:use-module (guix discovery)
+ #:use-module (guix memoization)
#:use-module (guix packages)
#:use-module (guix records)
#:use-module (guix gexp)
fringe@@ -34,6 +37,7 @@ (define-module (gnu services configuration)
warning))
#:use-module ((guix modules) #:select (file-name->module-name))
#:use-module (guix i18n)
+ #:use-module ((guix ui) #:select (warn-about-load-error))
#:autoload (texinfo) (texi-fragment->stexi)
#:autoload (texinfo serialize) (stexi->texi)
#:use-module (ice-9 curried-definitions)
fringe@@ -588,3 +592,49 @@ (define (generic-serialize-alist combine serialize-field fields)
@code{append} are usually good candidates for this."
(apply combine
(map (generic-serialize-alist-entry serialize-field) fields)))
+
+
+;;;
+;;; Configuration objects discovery.
+;;;
+
+(define %default-service-module-path
+ ;; Default search path for service modules.
+ `((,%distro-root-directory . "gnu/services")))
+
+(define (define-configuration? module symbol)
+ "Predicate to check if SYMBOL points to a `define-configuration'-generated
+object in MODULE."
+ (let ((fields-variable-name (symbol-append symbol '-fields)))
+ (or (module-local-variable module fields-variable-name) ;private variable
+ (module-variable module fields-variable-name)))) ;public variable
+
+(define (interface->directory interface)
+ "Convert a module interface to a module directory."
+ (resolve-module (module-name interface)))
+
+(define* (fold-configurations proc init
+ #:optional
+ (modules
+ (map interface->directory
+ (all-modules %default-service-module-path
+ #:warn
+ warn-about-load-error)))
+ #:key (select? (const #t)))
+ "Call (PROC MODULE SYMBOL RESULT) for each service configuration defined via
+`define-configuration' in the MODULES that matches SELECT?, using INIT as the
+initial value of RESULT. SELECT? is called with two arguments, the module
+object as well as the variable name (a symbol) of the configuration record
+constructor, e.g. @code{'forgejo-configuration}."
+ ;; FIXME: Contrary to its name, `fold-module-public-variables*' (and
+ ;; fold-module-public-variables) fold all the variables of a module,
+ ;; including the private ones. The distinction between public/private is
+ ;; made by whether the MODULES provided are whole modules (resolve-module)
+ ;; or just their exported interface (resolve-interface).
+ (fold-module-public-variables* (lambda (module symbol _ result)
+ (if (and (define-configuration? module symbol)
+ (select? module symbol))
+ (proc module symbol result)
+ result))
+ init
+ modules))
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