HS_NULL Constant

vat.h

#define HS_NULL ((HSym) {0, 0})

A null symbol constant.

HS_NULL is a null symbol. Many TIOS functions returns such a symbol in case of an error. Note that you can't check whether a some variable is HS_NULL using the "==" operator because HS_NULL is not scalar, i.e. you can't write something like

if (hs == HS_NULL) ...
Instead, check the folder field of HSym structure: if it is zero, the whole structure is HS_NULL, because TIOS never creates HSym structures in which the folder field is zero and the offset field is nonzero.