Translator – Multiple String Assignments (Release)

Upon contemplating the string flags in the table entries, I realized that care must be taken to make sure the string flag is set in the table entries when an operator or function code has a string operand. A better design is to set the string flag automatically during table initialization if any of the operands of the string data type. Therefore, the string flags were removed from the table entries and the Table constructor was modified set the flags in the table entries automatically.

To correct the issue of saving all the operands for string list assignments, a temporary simple stack is used to save the operands as they are popped off of the done stack and processed. Since the last two operands (the value being assigned and the last item in list) have already been popped and processed by the find code routine, these are pushed to the simple stack before processing the rest of the operands. Each additional operand processed is also pushed to this stack.

After the list operands are processed for a string list assignment a new array needs is allocated and filled from the temporary simple stack. In order to determine the size of this array, either the operands need to be counted as they are processed, or the number of items in the stack needs to be accessed. Since the simple stack already knows how many items it has, a new access function was added to the SimpleStack class to return the number of items.

It had been decided previously that mixed strings and sub-strings would be allowed in a multiple list assignment statement. Having a mix string list assignment replaces the need for a separate sub-string list assignment code, the mix-string list assignment will handle this case. So, a new AssignListMixStr associated code was added to AssignList (this new code has a sub-string as the first operand, the value being assigned). The list assignment handling code was modified to detect if the list contains both reference strings and sub-strings. If it does, then the token is changed to this new AssignListMixStr code.

Several new sub-string and mix-string assignments were added to test inputs. This completes string handling in the Translator. The code now handles expressions and assignment statements and ibcp_0.1.11-src.zip has been uploaded at Sourceforge IBCP Project along with the binary for the program. Next the real meat of the Translator begins, translating actual BASIC commands...