Il giorno sabato 26 febbraio 2022 alle 19:41:37 UTC+1 Dennis Lee Bieber ha scritto: > On Fri, 25 Feb 2022 21:44:14 -0800, Dan Stromberg <drsa...@gmail.com> > declaimed the following: > >Fortran, (still last I heard) did not support pointers, which gives Fortran > >compilers the chance to exploit a very nice class of optimizations you > >can't use nearly as well in languages with pointers. > > > Haven't looked much at Fortran-90/95 then... > > Variable declaration gained a POINTER qualifier, and there is an > ALLOCATE intrinsic to obtain memory. > > And with difficulty one could get the result in DEC/VMS FORTRAN-77 > since DEC implemented (across all their language compilers) intrinsics > controlling how arguments are passed -- overriding the language native > passing: > CALL XYZ(%val(M)) > would actually pass the value of M, not Fortran default address-of, with > the result that XYZ would use that value /as/ the address of the actual > argument. (Others were %ref() and %descr() -- descriptor being a small > structure with the address reference along with, say, upper/lower bounds; > often used for strings). > -- > Wulfraed Dennis Lee Bieber AF6VN > wlf...@ix.netcom.com http://wlfraed.microdiversity.freeddns.org/
The latest Fortran revision is the 2018. A variable can also have the VALUE attribute even though nowhere in the standard is written that it means passing the data by value. It just means that if a variable is changed in a procedure the changes don't propagate back to the caller. With the iso_c_binding one can directly call a C function or let a Fortran procedure appear as a C function. There is the C_LOC that gives the C address of a variable if needed. Of course from 2003 it is fully object oriented. The claim that it was faster then C is mostly related to the aliasing rule that is forbidden in Fortran. The C introduced the "restrict" qualifier for the same reason. In Fortran you also have array operation like you have in numpy. -- https://mail.python.org/mailman/listinfo/python-list
