Table – Add To Table Refactoring (Part 3)

The add to table function and all the functions it calls share several variables, which required them to be passed between the functions.  Enter the new Erector class to contain these functions and shared variables.  This class is a function operator class with a constructor that takes a table entry pointer, and the function operator function for adding the element to the table (static member variables).  This class was made a friend class of the table and table entry classes to make private member functions accessible.

The shared members of the Erector class include the table entry pointer being added, table entry pointer to the primary entry, table entry pointer to an alternate entry, and an operand index used for iterating and used by multiple functions.  Most of the member functions were declared in the header file after the class definition to not clutter up the class definition.  Each of these were declared inline since each is called once.  Two functions called multiple times were put into the source file.

Many of the functions were renamed again to better explain what they do.  There was addition refactoring moving statements up and done the functions during this renaming.  Not widely known (at least is wasn't to me) is that C++ contains alternate representations for the logical operators, for example and for &&, or for ||, and not for !.  To make the code a little more readable, the not operator was used since the ! operator can be head to see.

The main function was restructured to eliminate the need of the Done structure exception.  This unusual mechanism was used as sort of a goto to cause an exit from anywhere.  The elimination of this exception-exit mechanism was now possible since the sub-functions no longer returned table entry pointers (which are now member variables and set directly) opening up the use of boolean return values.

[branch table commit f199936e70]