case statements in uForth

case .. of .. endof .. endcase was surprisingly easy to implement:

\ Variable used to keep track of how many 'of' clauses we have.
\
variable _endof

: case ( n -- )
   0 _endof !
   [compile] >r
; immediate

: of ( n -- )
   [compile] r@
   [compile] =
   postpone if
; immediate

: endof ( -- )
   _endof incr
   postpone else
; immediate

: endcase ( -- )
   _endof @ 0 do postpone then loop
   [compile] r>
   [compile] drop
; immediate

And, an example:

: test  ( number -- )
    case
       1 of ." one" endof
       2 of ." two" endof
       3 of ." three" endof
       ." none"
    endcase
;