/* Coroutine mechanics for the sillier bits of the code */
#define crBegin1    static int crLine = 0;
#define crBegin2    switch(crLine) { case 0:;
#define crBegin        crBegin1; crBegin2;
#define crFinish(z)    } crLine = 0; return (z)
#define crFinishV    } crLine = 0; return
#define crReturn(z)    \
    do {\
        crLine=__LINE__; return (z); case __LINE__:;\
    } while (0)
#define crReturnV    \
    do {\
        crLine=__LINE__; return; case __LINE__:;\
    } while (0)
#define crStop(z)    do{ crLine = 0; return (z); }while(0)
#define crStopV        do{ crLine = 0; return; }while(0)
#define crWaitUntil(c)    do { crReturn(0); } while (!(c))
#define crWaitUntilV(c)    do { crReturnV; } while (!(c))

static int ssh1_rdpkt(unsigned char **data, int *datalen)
{
    struct rdpkt1_state_tag *st = &rdpkt1_state;

    crBegin;

  next_packet:

    pktin.type = 0;
    pktin.length = 0;

    for (st->i = st->len = 0; st->i < 4; st->i++) {
    while ((*datalen) == 0)
        crReturn(4 - st->i);
    st->len = (st->len << 8) + **data;
    (*data)++, (*datalen)--;
    }
    ...

           case 40:
             compatibility_level &= TM_VTXXX;
             break;
           case 41:
             compatibility_level = TM_PUTTY;
             break;
           case 42:
             compatibility_level = TM_SCOANSI;
             break;

               case 14:
            get_window_pixels(&x, &y);
            len = sprintf(buf, "\033[4;%d;%dt", x, y);
            ldisc_send(buf, len, 0);
            break;
               case 18:
            len = sprintf(buf, "\033[8;%d;%dt",
                     rows, cols);
            ldisc_send(buf, len, 0);

LD>/* Coroutine mechanics for the sillier bits of the code */
LD>#define crBegin1    static int crLine = 0;
LD>#define crBegin2    switch(crLine) { case 0:;
LD>#define crBegin        crBegin1; crBegin2;
LD>#define crFinish(z)    } crLine = 0; return (z)
LD>#define crFinishV    } crLine = 0; return
LD>#define crReturn(z)    \
LD>    do {\
LD>        crLine=__LINE__; return (z); case __LINE__:;\
LD>    } while (0)
LD>#define crReturnV    \
LD>    do {\
LD>        crLine=__LINE__; return; case __LINE__:;\
LD>    } while (0)
LD>#define crStop(z)    do{ crLine = 0; return (z); }while(0)
LD>#define crStopV        do{ crLine = 0; return; }while(0)
LD>#define crWaitUntil(c)    do { crReturn(0); } while (!(c))
LD>#define crWaitUntilV(c)    do { crReturnV; } while (!(c))
LD>

#define COROUTINE static int _coroutineState = 0; switch(_coroutineState) case 0:
#define YIELD(_expr_) do { _coroutineState = __LINE__; return (_expr_); case __LINE__:; } while(0)

char nextMove() // this was from a TCMM
{
    COROUTINE
    {
        while(1)
        {
            assert(depth == 0);
 
            while(condition1)
            {
                YIELD('R');
            }
 
            YIELD('D');
 
            while(condition2)
            {
                YIELD('R');
            }
 
            YIELD('U');
        }
    }
}