Iterators

• see Iterator system for info on how these functions are to be used

• sgs_PushIterator - create and push iterator from variable
• sgs_GetIterator - create iterator from variable
• sgs_IterAdvance - advance iterator, specified by its variable
• sgs_IterPushData - extract and push data of current iteration of the iterator, specified by its variable
• sgs_IterGetData - extract data of current iteration of the iterator, specified by its variable