*
* SORTBLK.KEX
*
* Sort groups of contiguous lines in a file and use the first line of each
* group to determine the sort order. Sorts are case insensitive. This is
* useful for sorting this like bibliography listings.
*
* The macro gathers a copy of all of the first lines of each block, puts them
* in a temporary file and sorts these. It then steps through the sorted file
* and uses it as an index to determine the proper order for the original file
* containing the blocks.
*
* Note: If you have any blocks of text that have identical first lines then
* these will not be sorted correctly. The macro assumes that each block of
* text has a unique first line.
*
* Works with:
*
*    KEDIT for Windows 1.5
*    KEDIT 5.0 for DOS
*    KEDIT 5.0 for OS/2
*
* Original author: Kent Downs MSG 8/96
*

"preserve"

"set autosave off"
"set wrap off"
"set zone 1 *"

BlockFile = fileid.1()
TempFile = "zzzzzzzz.zzz"
"kedit" TempFile "(new noprofile"
"kedit" BlockFile

* Go through the file, locate the first line of each paragraph and copy these
* lines to a scratch file.
"top"
do forever
   * Find the first line of the next block
   "nomsg locate ~blank"
   if rc > 0 then leave

   * Get a copy of it
   line = curline.3()

   * Place this in the scratch file
   "kedit" TempFile
   "input" line

   * Skip to the end of the current block
   "kedit" BlockFile
   "nomsg locate blank"
   if rc > 0 then leave
   end

* Sort the lines in the scratch file to make a sort of index of the blocks
"kedit" TempFile
"set case mixed ignore"
"sort all"
":1"

InsertPos = 0
SortCount = 0

* Reposition the blocks to their correct sort order
do forever
   * Get a copy of the next sorted item from the index
   SearchString = curline.3()

   * Find it in the block file
   "kedit" BlockFile
   "top"
   "find" SearchString
   "mark line"

   * Mark a line block around this block including all blank lines below it,
   * up to the next block
   "nomsg locate blank"
   if rc > 0 then do
      * The last block in the original file may not have a blank line after it
      "bottom"
      "add 1"
      end

   * Move to the start of the next block (if any) and back up one line
   "nomsg locate ~blank"
   if rc \= 0 then "*"
      else "backward 1 line"

   * Complete the block
   "mark line"

   * Move to the last line of the previously sorted block
   ":"InsertPos

   "move block"
   SortCount = SortCount + 1

   * Remember where to place the next block
   "sos blockend"
   InsertPos = line.1()
   "reset block"

   "kedit" TempFile
   "down 1"
   * Are we done?
   if focuseof() then leave
   end

* Throw away the index file
"kedit" TempFile
"qquit"
"kedit" BlockFile
"top"

"restore"
"sos beep"
say SortCount "text blocks sorted..."