Pelle Månsson Wrote:
> On 12/02/2010 09:05 AM, vincent picaud wrote:
> > Matthias Pleh Wrote:
> >
> >>
> >>>
> >>> Thank you for your reply and yes that works :)
> >>>
> >>> Now i m facing with the following problem, what is the trick for input
> >>> stream ?
> >>>
> >>> ( something like
> >>>
> >>> std::istream& operator>>(std::istream& in,A& a)
> >>> {
> >>> // A.someData<< in;
> >>> return in;
> >>> }
> >>>
> >>> in C++ )
> >>>
> >>> I m thinking of the situation when we want to load some data from a file.
> >>>
> >>> The toString() trick is okay for saving the object... but how to load it
> >>> back (something like fromString(char[]) would do the job but it does not
> >>> exist in Object) ?
> >>>
> >>> Anyway thank you, you solved half of my problem :)
> >>>
> >>>
> >>
> >> Ther are many posibilities, depending on your further needs! Just have a
> >> look at the online dokumentation:
> >> http://www.digitalmars.com/d/2.0/phobos/phobos.html
> >>
> >> But my first try would be such ..
> >> (note: I've leaved out error-handling ...)
> >>
> >> module test;
> >>
> >> import std.stdio;
> >> import std.file;
> >>
> >> class A
> >> {
> >> void writeToFile() { std.file.write("sample.txt",someData); }
> >> void readFromFile() { someData=cast(string)read("sample.txt"); }
> >> void clear() { someData="n/A\n"; }
> >> string toString() { return someData; }
> >> private:
> >> string someData="Just some data.
> >> With anohter line of date.
> >> Even more data.!";
> >> }
> >>
> >> int main(string[] args)
> >> {
> >> A a=new A;
> >> a.writeToFile();
> >> a.clear();
> >> writeln(a);
> >> a.readFromFile();
> >> writeln(a);
> >> return 0;
> >> }
> >
> > thank you for all your answers. I understand the approach, but in the same
> > time, I have the feeling that the C++ way is more convenient.
> >
> > Look in C++ , to define I/O for A, you do not have to modify your class A
> > and simply have to overload two functions:
> >
> > std::ostream& operator<<(std::ostream& out,const A& a)
> > std::istream& operator>>(std::istream& in,A& a)
> >
> > moreover this smoothly extend the I/O C++ framework without other side
> > effect.
> >
> > I was expecting to find a similar mecanism in D/Phobos
> >
> > Perhaps by overloading some read(), write() functions of the Phobos
> > library, but I do not know if it is "moral" to do that and which phobos
> > functions are concerned... IMHO there is a documentation hole here
> >
> >
>
> What you want is the new writeTo system for output. For input, a
> readFrom would be symmetrical and make sense :-)
>
> To actually use it, you would just do myFile.write(your, stuff, etc);
>
> For now, you can stringify using toString(). No way to read yet, except
> to!int, etc.
>
Yes, that is exactly what I want :)
Thanks
