variable (source-id)
variable (sink-id)

: source-id     (source-id) @ ;
: sink-id       (sink-id) @ ;

: emit          sink-id swap putc ;
: key           source-id begin
                  dup getc dup 0< while
                  drop
                repeat nip ;

: emit-file     swap putc 0 ;
: key-file      getc ;

0 constant black
1 constant red
2 constant green
3 constant yellow
4 constant blue
5 constant magenta
6 constant cyan
7 constant white

: -fg-color         #27 emit [char] [ emit [char] 0 emit [char] m emit ;
: +fg-color         #27 emit [char] [ emit
                    dup 8 < if #48 + [char] 3
                    else #40 + [char] 9
                    then emit emit [char] m emit ;
: hi-color          8 + ;