#define foreach_strpart(str, separator, pos, len) \
for(pos = str, len = 0; \
(pos) < ((str) + strlen(str)); \
pos = pos + len + strspn(pos, separator), len = strcspn(pos, separator)) \
if (len > 0)
#define foreach_strpart(str, separator, pos, len) \
for(pos = str, len = 0; \
(pos) < ((str) + strlen(str)); \
pos = pos + len + strspn(pos, separator), len = strcspn(pos, separator)) \
if (len > 0)