int weight_index; /* 0-based index of weight variable, or -1. */
struct caseproto *proto; /* Format of output cases. */
bool ok; /* Set false on I/O error. */
int weight_index; /* 0-based index of weight variable, or -1. */
struct caseproto *proto; /* Format of output cases. */
bool ok; /* Set false on I/O error. */