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> Date: Mon, 29 Mar 1999 08:01:27 -0800 (PST) > From: Richard Maine <[log in to unmask]> > > Klaus Ramstoeck writes: > > Agreed. And I am aware of at least one f90 compiler which works nicely for me. > > Alas not NAG, it choked on s.th. like > > select case > > case default > > print *, 'fails to compile' > > end select > > as I compiled my program elsewhere (reported earlier here). > > There were other problems as well which I however failed to nail down like this > > one. > > Two things. > > 1. If you have a nice short sample like that, I'd suggest sending a > bug report. I've found NAG to be quite good about responding to > well-written bug reports with concise samples. > > 2. But the above sample is not legal Fortran. Even if you can get > some compilers to accept it, I advise against doing something > so clearly non-standard that has so little obvious need for the > non-standard feature. I'll do non-standard things when it > fills a real need, but I don't see this particular syntax as > falling in that category. > > Yes, I can imagine some reasons why one might want a SELECT > statement that has nothing except for a CASE DEFAULT; for one > example, one might be planning to add some other cases at some > later time. > > But this isn't a legal syntax for doing so. The parens and > select-expression on the SELECT CASE statement are not optional; > even though they don't do much useful in this degenerate case, the > syntax requires them. The minimum change that occurs to me is to > make your select statement > > select case (0) > > With that change, the copy of the NAG compiler that I tried > (v2.2(303) for Sun Solaris 2 with gcc) worked fine. If you have > a version that doesn't work with the standard-conforming syntax, > then send a bug report to NAG. > > I could perhaps see merit to making the parens and the > select-expression optional in this degenerate case where they don't > really do anything useful. But since that isn't how the standard > reads, I'd advise against coding that way. > > -- > Richard Maine > [log in to unmask] Richard, One place I have used SELECT constructs with nothing between the SELECT and END SELECT statements, or just a default clause, is in code that was automatically generated by another program. In any case, earlier versions of the NAG compiler had a bug as follows. If the case-expr in the SELECT CASE statement was of type character, and the block was either empty or contained only a CASE DEFAULT, the compiler would generate incorrect C code. There was no problem for integer or logical case-exprs because those constructs were translated to C "switch" blocks, whereas for characters, the C code generated was if--else if--else. These bugs have been fixed in the latest versions. Ron Ronald Sverdlove Computing Systems Research [log in to unmask] Sarnoff Corporation Tel. 609-734-2517 CN 5300 FAX 609-734-2662 Princeton, NJ 08543-5300 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%