\ The idea for SET_OF below is from FD, May/Jun '97.  It's nice for situations
\ where you want something like

   DUP  14 =
   OVER 15 = OR
   OVER 18 = OR
   OVER 20 = OR
   OVER 25 = OR
   OVER 65 = OR
   IF bla bla bla ELSE ...

\ but in a CASE statement.  Normally in a case statement, you'd have to test for
\ each of these numbers, and then have the same code between the OF and ENDOF
\ that follows each.  You can't give OF more than one number to compare to, so
\ SET_OF takes care of that.  The situation above now all fits on the first OF
\ line of the example

   CASE
      { 14 15 18 20 25 65 } SET_OF   bla bla bla   ENDOF
                  <...>         OF      <...>      ENDOF
                  <...>         OF      <...>      ENDOF
      if-no-match-then-do-this-other-stuff
   ENDCASE

\ SET_OF allows a type of OF that can compare to several possible values that
\ can result in the same action.  The values can be literals, or they can be
\ fetched or calculated between the { and the } .   set_of is the internal
\ compiled by SET_OF.

\ Notice that { and } are not limited to have only literals between them.  You
\ can just as easily have some of the values calculated on the fly, as long as
\ you keep in mind that the number of comparisons that will be made by SET_OF
\ will be the difference between the stack depth immediately before } minus the
\ stack depth at { .  You cannot, for example, remove a previously existing cell
\ from the stack to calculate one of the comparison values unless you
\ specifically take action to correct the resulting stack-depth discrepancy.



: set_of                \ Syn: { 13 16 20 24 } SET_OF ... ENDOF       (internal)
   DUP 1+ PICK          \ Copy the argument that went into CASE
                        \ ^ arg T1 T2 ... Tn n arg
   FALSE  ROT 0         \ ^ arg T1 T2 ... Tn arg FALSE n 0
   DO                   \ 1st time into loop: ^ arg T1 T2 ... Tn arg FALSE
      OVER 3ROLL = OR
   LOOP                         \ After last loop: ^ arg arg flag
   ?EXIT   NOT          ;       \ If flag was false, change one copy
                                \ of arg so they don't match.


\ SET_OF works very much like OF .  It does not make sure you preceded it with
\ { ... } .  I may decide to add that to the compiler security in the future.


: SET_OF   ( CASECODE n -- CASECODE ADR n+1 OFCODE )        \   (FD May/Jun '97)
   ?COMP                                                    \ Related:  RANGE_OF
   >R R@ PICK 6 ?PAIRS
      COMPILE set_of  COMPILE of
      HERE 0 ,
   R> 1+     7          ;       IMMEDIATE