Table – Entry Pointers

The new table implementation will have a single Table class that will represent a table entry for a single code and will serve as the base class to all of the derived table entry classes.  Global table information (name to entry map, alternate code map, etc.) will be static members of this class.  This is equivalent to the current since table instance.

Currently the Table class and Table Entry structure are separate definitions, but eventually the table entry members will be members of the new base table class.  The current table class has many access functions where their first argument is a code enumerator (which is currently used as an index).  There are also many access functions that have a token pointer as their first argument, but this is mostly used to get the code from the token.

The new table model will access the table entries by a pointer to the entry instead of be a code enumerator used as an index.  The code argument access functions will become simply access functions to the table entry.  The next step in this transition to the new table model will be to use pointers to table entries instead of code enumerators.  The token code member will become a table entry pointer.

To start this transition, the Table Entry structure was moved from the table source file to the table header file.  The members were also renamed with the member (m_) prefix except for the function pointer members (which will be replaced with virtual functions in the new table model).

[branch table commit 94decad26c]

Table – Internal Code Token Types

There were several internal code table entries (null, assignment, print item, input assign and input parse) that were assigned to either an Operator or Internal Function token type.  These internal codes do not require a token type because they are not produced by the parser (the token type is only used for tokens from the parser).  These table entries were changed to the default token type (in other words, no type).

The reason for this change will become more evident when the new table class hierarchy is implemented.  One of the goals of which is to reduce the amount of unnecessary initialization values.  It may even turn out that the token type member of all table entries will be unnecessary, but this is not clear yet.

These changes did cause a minor issue in test output.  By default the test output stream insert operator for a token outputs nothing for a token without a type, which cause the above modified codes to not produce their debug name.  This function was modified to output the debug name in the default case instead of doing nothing.  Since the internal function types also only output the debug name, these cases were removed to let the default case handle these types.

[branch table commit 232a97f6d6]

Table – New Token Consolidation

The next major change to the table class will be to start transitioning to using table entry pointers instead of code enumerators and to remove the use of code enumerators as indexes.  The code and index values will be separate members of table entries.  All table entries will have an index (which is put into the program code), but only a few table entries will have a code (only those the require specific lookup like some of the special symbols including comma, parentheses, colon, etc.).  Before proceeding with this, a small simplification was made first.

There were two new token functions in the table class, one taking a single code argument and the other taking column, length and code arguments.  The single argument version relied on the default token constructor.  This was one of three uses of the default token constructor.  The default token constructor contained optional column and length arguments (default to -1 indicating unset), but there were no callers of the default token constructor that used these arguments.

The single code argument new token function was removed along with the default token constructor.  The code argument was made the first argument of the other version of the new token function with default -1 values provided for the optional column and length arguments.  This second version does not use the default token constructor.  All callers of this function were in the parser and were modified for the reordering of the arguments.

The second use of the default token constructor was by the decode function in the program model class to create a default token, which it then used the token set code access function to set the code.  This function was changed to use the new token function.

The third use of the default token constructor was in the INPUT translate function where a new token is needed for an input assign code and another token (comma or semicolon) is not available for reuse.  This was changed to use the new token function with a Null code.

[branch table commit b5dd96c272]