Translator – Debugging - Sub-String Assignments

There were no issues with the seventh (Data Type Assignment) Translator tests other than the expected text file needed to be updated for all the new operator codes. The eighth (Sub-String Assignment) tests were all failing with a bug message indicating the done stack was empty when it was expecting operands and one of the tests were crashing the program.

The done stack empty errors were caused because the string within the sub-string that was being assigned was already popped off of the done stack by the assignment (variables being assigned do not need to be attached to the assignment token). But when the sub-string function was processed, it expected to find the first operand, which is a string, on the done stack. A check needed to be added to the process final operand function to not count string operands for functions that have the reference flag set (which is only set for sub-string functions on the left side of an assignment statement).

The next issue for the sub-string assignment tests, was that the Translator was incorrectly adding an AssignStr code instead of the correct AssignSubStr code. This problem was caused because the find code routine was using the wrong condition to check for an exact data type match when looking at the operands of the main and associated codes to find the proper code for the operand. The code obtained from the conversion code table was used – the exact match check was if the conversion code was the Null code. This allowed the Sub-String data type to match the AssignStr that was expecting a String data type instead of continuing to check the AssignSubStr, which expects the Sub-string data type.

To correct this problem, the exact match check was changed to compare the actual data type to the code's operand's data type. This is the check the old find code routine used. Also, the section that inserts the conversion code was modified to only add the conversion code from the conversion table if it is not the Null code. In other words, the Null code indicates that the data type can be converted, but no actual conversion code is needed.