Merge remote-tracking branch 'origin/master' into staging

[jackhill/guix/guix.git] / gnu / services / configuration.scm

diff --git a/gnu/services/configuration.scm b/gnu/services/configuration.scm
index 2ad3a63..707944c 100644 (file)
--- a/gnu/services/configuration.scm
+++ b/gnu/services/configuration.scm
@@ -1,5 +1,7 @@
 ;;; 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>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -36,6 +38,7 @@
             configuration-field-default-value-thunk
             configuration-field-documentation
             serialize-configuration
+            define-maybe
             define-configuration
             validate-configuration
             generate-documentation
@@ -71,11 +74,12 @@
   (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))
+  #~(string-append
+     #$@(map (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)
@@ -85,16 +89,27 @@
                    (configuration-field-name field) val))))
             fields))
 
+(define-syntax-rule (id ctx parts ...)
+  "Assemble PARTS into a raw (unhygienic)  identifier."
+  (datum->syntax ctx (symbol-append (syntax->datum parts) ...)))
+
+(define-syntax define-maybe
+  (lambda (x)
+    (syntax-case x ()
+      ((_ stem)
+       (with-syntax
+           ((stem?                (id #'stem #'stem #'?))
+            (maybe-stem?          (id #'stem #'maybe- #'stem #'?))
+            (serialize-stem       (id #'stem #'serialize- #'stem))
+            (serialize-maybe-stem (id #'stem #'serialize-maybe- #'stem)))
+         #'(begin
+             (define (maybe-stem? val)
+               (or (eq? val 'disabled) (stem? val)))
+             (define (serialize-maybe-stem field-name val)
+               (if (stem? val) (serialize-stem field-name val) ""))))))))
+
 (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 ...)
@@ -133,7 +148,7 @@
                    conf))))))))
 
 (define (serialize-package field-name val)
-  #f)
+  "")
 
 ;; A little helper to make it easier to document all those fields.
 (define (generate-documentation documentation documentation-name)
@@ -152,7 +167,7 @@
                                (configuration-field-default-value-thunk f)
                                (lambda _ '%invalid))))
                 (define (show-default? val)
-                  (or (string? default) (number? default) (boolean? default)
+                  (or (string? val) (number? val) (boolean? val)
                       (and (symbol? val) (not (eq? val '%invalid)))
                       (and (list? val) (and-map show-default? val))))
                 `(deftypevr (% (category