new file mode 100644
@@ -0,0 +1,63 @@
+(define-module (gnu home-services configuration)
+ #:use-module (gnu services configuration)
+ #:use-module (guix gexp)
+ #:use-module (srfi srfi-1)
+
+ #:export (filter-configuration-fields
+
+ interpose
+ list-of
+
+ list-of-strings?
+ alist?
+ string-or-gexp?
+ serialize-string-or-gexp
+ text-config?
+ serialize-text-config))
+
+(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 an
+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))
+
+(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-strings?
+ (list-of string?))
+
+(define alist? list?)
+
+(define (string-or-gexp? sg) (or (string? sg) (gexp? sg)))
+(define (serialize-string-or-gexp field-name val) "")
+
+(define (text-config? config)
+ (and (list? config) (every string-or-gexp? config)))
+(define (serialize-text-config field-name val)
+ #~(string-append #$@(interpose val "\n" 'suffix)))
@@ -75,6 +75,7 @@ GNU_SYSTEM_MODULES = \
%D%/home-services.scm \
%D%/home-services/symlink-manager.scm \
%D%/home-services/fontutils.scm \
+ %D%/home-services/configuration.scm \
%D%/image.scm \
%D%/packages.scm \
%D%/packages/abduco.scm \