Translator – New Find Code (Multiple Flag)

The next issue for the new find code implementation is with internal functions that have different number of arguments (MID$, INSTR and ASC). Currently the number of arguments is checked at the closing parentheses before the call to find code to check the data types of the arguments. Before calling find code, if the number of arguments was not correct, but the Multiple Flag was set, then a search for another code was made where the number of arguments did match.

For the new implementation, the data types of the internal function arguments will be checked as each argument is processed – in other words, at the comma token (or close parentheses token for the last argument). The checking for an alternate form of the internal function will now take place in the comma token handler.

Previously to support checking if a comma was valid in an internal function call (as opposed to a closing parentheses), the internal function table entry with the most number of arguments had to first in the table because otherwise an error would occur since a closing parentheses would be expected if the table entry with the smaller number of arguments was listed first. The number of arguments would be checked, and the code changed if necessary, in the closing parentheses token handler.

Now with the comma token handler taking care of changing the code when needed, the smaller number of arguments table entry needs to be first. If a comma is received where a parentheses is expected (at the last argument), a check will be made and if the Multiple Flag is set then it will move to the next table entry with the next number of argument (otherwise an “expected closing parentheses” error occurs).

This method implies that the table entries for the number of arguments must be in order by number of arguments. If there are three forms of an internal function (there are currently none), then the Multiple Flag should be in each table entry except the last. To insure the table entries are placed in the table correctly, a check will be added to the table initialization along with the other current table checks.