Translator Exceptions – Operators

The process operator function called by the get expression function was modified to throw errors.  This function returned Done status for a token that is not an operator, Good status for a successfully processed unary or binary operator, or an error status.  Since errors on now thrown, the return type was changed to a boolean, true for success and false for not an operator.

The process done stack top function is used to pop an item from the done stack and add a conversion code to the output if needed or report an error if the item can't be converted.  This function used by the process final operand, INPUT translate, and LET translate functions was  modified to throw the error and its return type was removed.  These callers were modified to just call the function and any error thrown will the passed to their caller.

Similarly, the process operator function was changed to just call the process final operand function, and its error is not caught passing any error thrown up to its caller, which is the get expression function.

The process first operand function was called to process the first operand of a binary operator, and push the unary or binary operator to the hold stack.  At first it was also modified to throw errors (again from the process done stack top function), but this function ended up being only a few lines, and since is only called by the process operator function, its code was just moved into the process operator function eliminating the separate function.

The get expression was temporarily modified to catch errors from the process operator function where the status is obtained from the thrown error, and an error token is created from the error column and length.  The error status and the token is returned as before.  This won't be necessary once get expression is modified to throw errors.

[branch misc-cpp-stl commit cf45a8e393]