[PATCH] Provide address@hidden' for numbered displays

[Ludovic Courtès]

Hi,

The attached patch provides an address@hidden' option for numbered
displays.  Although it works fine, there's certainly room for
improvement, e.g., renaming address@hidden' to something more
meaningful.

Thanks,
Ludovic.

--- orig/include/bsf
+++ mod/include/bsf
@@ -295,6 +295,25 @@
 
     ###########################################################################
     #                                                                         #
+    #  x @Dft y                                                               #
+    #                                                                         #
+    #  This returns x unless its value is "dft", in which case it returns y.  #
+    #  Useful for defaulting the value of one parameter to another.           #
+    #                                                                         #
+    ###########################################################################
+
+    def @Dft
+       left x
+       right y
+    {
+       x @Case {
+           "dft" @Yield y
+           else  @Yield x
+       }
+    }
+
+    ###########################################################################
+    #                                                                         #
     #   @Pipe, @PipeVerbatim, and @PipeRawVerbatim                            #
     #                                                                         #
     ###########################################################################
@@ -1363,11 +1382,17 @@
     }
 
     def @NumDispCounterIncrement
+       named @BypassNumber { "dft" }
        right tag
     {
+       def @DisplayNumber
+       {
+           @BypassNumber @Dft { @NumDispNum tag }
+       }
+
        @NumDispCounterMarker&&preceding @Tagged tag
-       @NumDispCounterMarker val { @NumDispNum tag }
-       @NumberMarker @Tag { tag } @Value { @NumDispNum tag }
+       @NumDispCounterMarker val { @DisplayNumber }
+       @NumberMarker @Tag { tag } @Value { @DisplayNumber }
     }
 
     def @NN
@@ -1409,10 +1434,11 @@
 
     def @NDisp into { @DispPlace&&preceding }
        named @Tag {}
+       named @BypassNumber { "dft" }
        right x
     {
        @OneRow {
-          @NumDispCounterIncrement @Tag
+          @NumDispCounterIncrement @BypassNumber { @BypassNumber } @Tag
           @PageMark @Tag
           ^//
           @OneRow x
@@ -1427,10 +1453,11 @@
 
     def @ANDisp into { @AlignedPlace&&preceding }
        named @Tag {}
+       named @BypassNumber { "dft" }
        right x
     {
        @OneRow {
-          @NumDispCounterIncrement @Tag
+          @NumDispCounterIncrement @BypassNumber { @BypassNumber } @Tag
           @PageMark @Tag
           ^/
           @OneRow x