Path: utzoo!attcan!uunet!mcvax!cernvax!hjm From: hjm@cernvax.UUCP (Hubert Matthews) Newsgroups: comp.lang.forth Subject: Re: Extensible or Preprocessor Message-ID: <837@cernvax.UUCP> Date: 26 Sep 88 17:00:44 GMT References: <1593@crete.cs.glasgow.ac.uk> <810002@hpmtlx.HP.COM> <1650@crete.cs.glasgow.ac.uk> Reply-To: hjm@cernvax.UUCP (Hubert Matthews) Organization: CERN European Laboratory for Particle Physics, CH-1211 Geneva, Switzerland Lines: 16 One problem with pre-processors is error handling. Consider a PP that translates Ratfor into FORTRAN IV. Whilst the program is running, a division by zero occurs and an error is reported. The line number returned is the number of the line that caused this exception, but in the FORTRAN program and not the Ratfor program. The user then has to examine the PP output in order to determine the correspondance between his view (the Ratfor) and the PP's view of his code. In an extensible language, the error line number refers directly to the user's code and not to an intermediate representation. Do you prefer an error message that says "div by zero in line 364" or "div by zero at PC=00247AFC"? Hubert Matthews -- Hubert Matthews