Avoid `blabla: none' messages in internal documentation.

[lilypond.git] / scm / document-backend.scm

diff --git a/scm/document-backend.scm b/scm/document-backend.scm
index d291b2299cdad34e1d307931fd1fb8d1712dec4a..02a09736b0927715bde6dfe74458599d14d300e8 100644 (file)
--- a/scm/document-backend.scm
+++ b/scm/document-backend.scm
@@ -1,7 +1,7 @@
 ;;;; backend-documentation-lib.scm -- Functions for backend documentation
 ;;;;
 ;;;; source file of the GNU LilyPond music typesetter
-;;;; 
+;;;;
 ;;;; (c) 2000--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
 ;;;; Jan Nieuwenhuizen <janneke@gnu.org>
 
@@ -53,19 +53,26 @@
 
 ;; First level Interface description
 (define (interface-doc interface)
-  (let ((name (symbol->string (car interface))))
+  (let* ((name (symbol->string (car interface)))
+        (interface-list (human-listify
+                         (map ref-ify
+                              (sort
+                               (map symbol->string
+                                    (hashq-ref iface->grob-table
+                                               (car interface)
+                                               '()))
+                               string<?)))))
     (make <texi-node>
       #:name name
       #:text (string-append
              (interface-doc-string (cdr interface) '())
              "\n\n"
-             "This grob interface is used in the following graphical objects: "
-             (human-listify
-              (map ref-ify
-                   (sort 
-                    (map symbol->string
-                         (hashq-ref iface->grob-table (car interface) '()))
-                    string<?)))
+             "This grob interface "
+             (if (equal? interface-list "none")
+                 "is not used in any graphical object"
+                 (string-append
+                  "is used in the following graphical object(s): "
+                  interface-list))
              "."))))
 
 (define (grob-alist->texi alist)
@@ -92,21 +99,32 @@ node."
                              (ly:error (_ "pair expected in doc ~s") name)))
                        (reverse ifaces)))
         (engravers (filter
-                    (lambda (x) (engraver-makes-grob? name x)) all-engravers-list))
+                    (lambda (x) (engraver-makes-grob? name x))
+                    all-engravers-list))
         (namestr (symbol->string name))
-        (engraver-names (map symbol->string (map ly:translator-name engravers))))
+        (engraver-names (map symbol->string
+                             (map ly:translator-name engravers)))
+        (engraver-list (human-listify
+                        (map ref-ify
+                             (map engraver-name engraver-names)))))
 
     (make <texi-node>
       #:name namestr
       #:text
       (string-append
-       namestr " objects are created by: "
-       (human-listify (map ref-ify
-                          (map engraver-name engraver-names)))
+       namestr " objects "
+       (if (equal? engraver-list "none")
+          "are not created by any engraver"
+          (string-append
+           "are created by: "
+           engraver-list))
+       "."
+
        "\n\nStandard settings: \n\n"
        (grob-alist->texi description)
-       "\n\nThis object supports the following interfaces: \n"
-       (human-listify ifacedoc)))))
+       "\n\nThis object supports the following interface(s): \n"
+       (human-listify ifacedoc)
+       "."))))
 
 (define (all-grobs-doc)
   (make <texi-node>