From 9d8bd8dfbcd71464a17bf3e12546868a5c9e0580 Mon Sep 17 00:00:00 2001
From: Ludovic Courtes
Date: Sun, 23 Jul 2006 20:49:08 +0000
Subject: Fixed `engine-add-writer!' so that the insertion order is kept.

* src/guile/skribilo/engine.scm (engine-add-writer!): Use `append'
  instead of `cons' when adding a writer, so that the insertion order is
  honored when lookups are performed.  This fixes a generation bug (e.g.,
  for the first page of the User Manual) and slightly improves
  performance.

* src/guile/skribilo/writer.scm (lookup-markup-writer): Documented the
  impact of registration order.

git-archimport-id: lcourtes@laas.fr--2005-libre/skribilo--devo--1.2--patch-22
---
 src/guile/skribilo/engine.scm | 9 ++++++---
 src/guile/skribilo/writer.scm | 3 ++-
 2 files changed, 8 insertions(+), 4 deletions(-)

(limited to 'src')

diff --git a/src/guile/skribilo/engine.scm b/src/guile/skribilo/engine.scm
index c422476..401f9ef 100644
--- a/src/guile/skribilo/engine.scm
+++ b/src/guile/skribilo/engine.scm
@@ -313,7 +313,9 @@ otherwise the requested engine is returned."
   ;; Add a writer to engine E.  If IDENT is a symbol, then it should denote
   ;; a markup name and the writer being added is specific to that markup.  If
   ;; IDENT is `#t' (for instance), then it is assumed to be a ``free writer''
-  ;; that may apply to any kind of markup for which PRED returns true.
+  ;; that may apply to any kind of markup for which PRED returns true.  The
+  ;; order in which writers are added matters (it should be the same as the
+  ;; lookup order), hence the use of `append' below.
 
   (define (check-procedure name proc arity)
     (cond
@@ -359,9 +361,10 @@ otherwise the requested engine is returned."
     (if (symbol? ident)
 	(let ((writers (slot-ref e 'writers)))
 	  (hashq-set! writers ident
-		      (cons n (hashq-ref writers ident '()))))
+		      (append (hashq-ref writers ident '())
+			      (list n))))
 	(slot-set! e 'free-writers
-		   (cons n (slot-ref e 'free-writers))))
+		   (append (slot-ref e 'free-writers) (list n))))
     n))
 
 
diff --git a/src/guile/skribilo/writer.scm b/src/guile/skribilo/writer.scm
index b46cddc..4750e57 100644
--- a/src/guile/skribilo/writer.scm
+++ b/src/guile/skribilo/writer.scm
@@ -163,7 +163,8 @@
 
 (define (lookup-markup-writer node e)
   ;; Find the writer that applies best to NODE.  See also `markup-writer-get'
-  ;; and `markup-writer-get*'.
+  ;; and `markup-writer-get*'.  Writers are looked up in the order in which
+  ;; they were registered.
 
   (define (matching-writer writers)
     (find (lambda (w)
-- 
cgit v1.2.3