#
# split(s, delimiters, keepall) splits the string s into consecutive substrings
#  that do/do not consist of characters in the cset delimiters, producing a
#  list of strings.  If keepall is null, strings consisting of delimiters are not
#  included in the result list.
#
# If not specified, delimeters defaults to blank and tab, which essentially
# "tokenizes" non-whitespace:
#
#   words := split(read())
#
# Author: William H. Mitchell (whm@mse.com) c. 1996
#
procedure split(s, dlms, keepall)
   local w, ws, addproc, nullproc

   ws := []
   /dlms := " \t"
   
   addproc := put
   if \keepall then
      otherproc := put
   else
      otherproc := 1
   
   if dlms := (any(dlms, s[1]) & ~dlms) then
      otherproc :=: addproc
    
   s ? while w := tab(many(dlms := ~dlms)) do {
      addproc(ws, w)
      otherproc :=: addproc
      }

   return ws
end