field_type
us_type2str(unsigned field_type)
switch (field_type) {
gf_populate_params(ECCurveName name, ECFieldType field_type, ECParams *params,
params->fieldID.type = field_type;
if (field_type == ec_field_GFp) {
extern FIELDTYPE * field_type(FIELD *);
extern FIELDTYPE * field_type();