Update SVGSerialize to use three-digit zero-padding for frame numbers in generated SVG filenames for improved lexicographic sorting.

Two digits turned out to be too conservative.  For example, the solution to the SlidingPuzzle.tla of the TLA+ examples is longer.

Signed-off-by: Markus Alexander Kuppe <[email protected]>

Author: lemmy

modules/SVG.tla

@@ -230,16 +230,16 @@ PointOnLine(from, to, segment) ==
 (*   SVGSerialize(SVGDoc(myElements, 0, 0, 800, 600, <<>>),               *)
 (*                "svg_frame_", TLCGet("level"))                          *)
 (*                                                                        *)
-(* This creates files like: svg_frame_01.svg,                             *)
-(*                          svg_frame_02.svg, etc.                        *)
+(* This creates files like: svg_frame_001.svg,                            *)
+(*                          svg_frame_002.svg, etc.                       *)
 (**************************************************************************)
 SVGSerialize(svg, frameNamePrefix, frameNumber) ==
     LET IO == INSTANCE IOUtils IN
     IO!Serialize(
         SVGElemToString(svg),
         \* Construct the filename using the prefix and a zero-padded frame
         \* number so that files sort correctly lexicographically.
-        frameNamePrefix \o IO!zeroPadN(frameNumber, 2) \o ".svg",
+        frameNamePrefix \o IO!zeroPadN(frameNumber, 3) \o ".svg",
         [format |-> "TXT", charset |-> "UTF-8", 
          openOptions |-> <<"WRITE", "CREATE", "TRUNCATE_EXISTING">>])