subroutine reference
in [Fortran]
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From: david on 9 Jun 2010 10:54 Hello, It seems that it is possible in fortran to give a function name to a subroutine/function, to call it later. Is it possible to give a subroutine adresse to a subroutine/function, to call it later ? like in C: void sub (void (*subroutine)(int param)) { subroutine(1); } Thanks for any tips david
From: mecej4 on 9 Jun 2010 11:15 On 6/9/2010 9:54 AM, david wrote: > Hello, > > It seems that it is possible in fortran to give a function name > to a subroutine/function, to call it later. > > Is it possible to give a subroutine adresse to a > subroutine/function, to call it later ? > > > like in C: > void sub (void (*subroutine)(int param)) > { > subroutine(1); > } > > > > Thanks for any tips > > david This has been possible for decades. See, for example, Section 5.12 of Metcalf, Reid and Cohen, Fortran 95/2003 Explained, OUP, 2004. If using Fortran 77, read about the EXTERNAL declaration. If using Fortran 9X, read about procedure arguments and interface declarations. --mecej4
From: Richard Maine on 9 Jun 2010 11:22 david <deyv(a)free.fr> wrote: > It seems that it is possible in fortran to give a function name > to a subroutine/function, to call it later. I'm confused as to what you are saying here. No, it is not possible to give a function name to a subroutine. Functions and subroutines are separate. Some compilers might not catch the error, but it *IS* an error to invoke a function as a subroutine or vice versa. > Is it possible to give a subroutine adresse to a > subroutine/function, to call it later ? Again, subroutines and functions are separate. Both are procedures, and can do many of the same kinds of things, but you cannot change a subroutine into a function. It sounds somewhat like you are asking for procedure pointers, which are new to the standard in f2003. Those do allow you to pointer assign a procedure in one place and then reference it in another. But they have nothing to do with confusing subroutines and functions. -- Richard Maine | Good judgment comes from experience; email: last name at domain . net | experience comes from bad judgment. domain: summertriangle | -- Mark Twain
From: david on 9 Jun 2010 12:15 mecej4 <mecej4_no_spam(a)operamail.com> wrote: > On 6/9/2010 9:54 AM, david wrote: > > Hello, > > > > It seems that it is possible in fortran to give a function name > > to a subroutine/function, to call it later. > > > > Is it possible to give a subroutine adresse to a > > subroutine/function, to call it later ? > > > > > > like in C: > > void sub (void (*subroutine)(int param)) > > { > > subroutine(1); > > } > > > > > > > > Thanks for any tips > > > > david > This has been possible for decades. See, for example, Section 5.12 of > Metcalf, Reid and Cohen, Fortran 95/2003 Explained, OUP, 2004. > If using Fortran 77, read about the EXTERNAL declaration. If using > Fortran 9X, read about procedure arguments and interface declarations. You are right, it is possible and I confused myself writing the question. I'm sorry about that. My real question: is it possible to store a "subroutine address" into a variable to call it later. - like in C : /* subroutine address variable */ void (*subroutine_addr)(int param); void sub2 (void) { subroutine_addr(1); } void sub (void (*subroutine)(int param)) { subroutine_addr = subroutine; sub2(); } david
From: david on 9 Jun 2010 12:18
Richard Maine <nospam(a)see.signature> wrote: > david <deyv(a)free.fr> wrote: > It sounds somewhat like you are asking for procedure pointers, which are > new to the standard in f2003. Those do allow you to pointer assign a > procedure in one place and then reference it in another. But they have > nothing to do with confusing subroutines and functions. You are right, I'm asking about procedure pointers ! Thanks very much, I did not go that far. I'll check the new standards. Sorry about asking confusing questions, I'll try to do better next time. david |