Translator Exceptions – Tokens

The get token function used to get the next token from the parser was modified to throw errors.  The return type was removed since a no exception return now indicates success.  The temporary error token for an error no longer needs to be created.  The Good status that was previously returned for success was no longer used, so this status enumerator was removed.

All the callers of the get token function were modified for errors being thrown, which mostly included catching the error and throwing the appropriate error for the Unknown Token error. The get operand function just passes the error on to its caller (In this case, in addition to an Unknown Token error, a number constant error could be returned for non-reference token requests).

The get expression function was modified to catch the error from the get token function, obtain the error status and create an error token.  Th error token won't be necessary once this function is modified to throw errors (which is now the only function remaining now modified yet to throw errors).

In the LET translate function where the token after a reference token is not a comma or equal character, the token on top of the done stack was checked to see if it has the sub-string flag set, and if is does this item (a sub-string assignment function) is popped.  This is not necessary since once an error is thrown out of the translator, the translator instance is deleted along with the done stack.

[branch misc-cpp-stl commit 217de6d02c]