bool var_is_valid_name (const char *, bool issue_error);
int compare_var_names (const void *, const void *, void *);
unsigned hash_var_name (const void *, void *);
bool var_is_valid_name (const char *, bool issue_error);
int compare_var_names (const void *, const void *, void *);
unsigned hash_var_name (const void *, void *);