Table – Expected Data Type

The expected data type table entry member was recently moved from the Expression Info structure (because codes using the same return and operand data types could have different expected data types).  There were several issues with the expected data types initialization implementation (which were initialized automatically to prevent programming mistakes):

• Every table entry had an expected data type even it is was never used (for example, commands).  Even when it was in the Expression Info structure, it was not used for many codes (no argument functions, assignment codes, etc.).
• A separate iteration loop was needed to initialize the expected data types since the alternate code information was used, the alternate code map needed to be initialized first.
• The expected data type initialization took into account if a code had the possibility of having all three data types (Double, Integer, and String) where the expected data type would be set to Any even though there were actually such codes.

This implementation was replaced with a new table entry pointer to expected data type static map member.  Only table entries requiring an expected data type are added to this map.  This includes all primary codes and any alternate primary code.  An alternate primary code is the primary code for the second operand, for example, a binary operator with two integer operands (where the primary has two double operands).  Entries are added to the expected data type in the add function when:

• A new entry is added to the name to entry map (a new primary code).
• An entry is replaced in the name to entry map (a new primary when the operand count is less than the current primary; and in this case the old entry is removed for an internal function).
• A new secondary primary is added to the alternate code map (a binary operator to a unary operator).
• A replacement alternate primary is found (one that has the same operands, see last post; the old alternate primary entry is removed).
• A new alternate primary is found (the alternate is added for the first operand of a binary operator, otherwise the current entry of the primary is modified).

An add expected data type private support function adds or modifies an entry to the expected data type taking table entry pointer and data type arguments.  If there is currently no entry, a new entry is added.  If there is an entry and its data type is Double or Integer, then the entry is changed to Number (the new data type will be either Integer or Double).  Otherwise, the entry is left unchanged.

The expected data type access function was modified to use the new map.  The expected data type member was removed from the Table Entry structure, and its initializer values were removed from the table entries.  The separate iteration loop in the table constructor to initialize the expected data types was removed.

A problem was found in the set token code function (used to set the code in a token, possibly an alternate code, depending on its data type) where it could incorrectly add a new blank element to the alternate code map.  This did not appear to cause a problem, but was corrected by checking if the code is present before iterating over alternate codes.  This issue was that for a standard map, the bracket operator adds blank elements if the key does not exist.

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