Daniel Krueger scripsit: > I wonder if it would be the simplest way to specify that the file is > only and always open in the procedure passed to call-with-input-file. > So an implementation would close the file upon exit (regardless which > one) of the procedure, saving the state so that upon reentrance of the > procedure the file would be reopened and restored to the state on exit > (so seek to the old position etc.) using dynamic-wind.
This is not always possible: some files aren't seekable; some may not even be reopenable, if they have been deleted while open (not possible on Windows, but possible on Posix systems). > In fact, this also applies partially to call/cc, which is in some > implementations also more of a hack involving stack-copying, isn't it? Some implementations, but by no means all. It's also possible to keep procedure activations in the heap, or to use Cheney on the MTA. > This is not the fault of the standard, but a problem of the > implementations of other programming languages (having some > restrictions) which force the implementors to do these hacks in order > to interact with these languages. Nevertheless, the standard can't just ignore implementation barriers. -- Using RELAX NG compact syntax to John Cowan <[email protected]> develop schemas is one of the simple http://www.ccil.org/~cowan pleasures in life.... --Jeni Tennison <[email protected]> _______________________________________________ Scheme-reports mailing list [email protected] http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports
