/*  table implementation of is_operator() */ 

#define is_operator(ch)            (is_operator_bit[(ch)&0377]) 

static const char is_operator_bit[256] = 
{ 

    0,                             /* position 0 */ 
    0, 0, ...                      /* another 41 zeroes */ 
    1,                             /* '*', position 42 */ 
    1,                             /* '+' */ 
    0, 
    1,                             /* '-' */ 
    0, 
    1,                             /* '/', position 47 */ 
    0, 0, ...                      /* 208 more zeroes */ 
};