Program – Removing RPN List Dependency

The pointer to the RPN list of a program line from the translator is currently being held in the line information list for the program (along with offset and size of the line and an index to the error list if the line has an error).  This pointer will eventually be removed since the RPN list is not needed after a line is encoded and stored in the program.  There were two dependencies on the RPN list that needed to be removed.

The program model update error routine used the RPN list from an line information list item to determine if the line has an error.  If it did, an error item is created from the RPN list (retrieving the error column, error and message) and stored in the error list.  The index of the error item in this list is then stored in the line information item for the line.

Since the RPN list pointer is going to be removed from the line information list, the update error routine was modified to obtain the error information differently.  Instead of creating the error item in this routine, the error item is now created in the calling update line routine just after the line is translated and checked for an error.  The error item with the error information is passed to the update error routine, which was modified to use it instead of the RPN list.

So that an empty error item can be indicated, a new none error type was added to the error item class.  An is empty access function was added to return if the error item does not contain an error.  A default constructor was added to create an empty error item.  Also for clarity, the translator and encoder error types were renamed to the input and code error types.

Even though currently no encoder errors can occur, the error item constructor was modified from having an RPN list pointer argument to having arguments for the error column, length and message.  This will allow setting errors from encoding without an RPN list (the error item class is no longer dependent on the RPN list class).

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