• Manfred Nowak <svv1999 hotmail.com> Dec 20 2011
• "Kagamin" <spam here.lot> Dec 20 2011
• =?ISO-8859-1?Q?Alex_R=F8nne_Petersen?= <xtzgzorex gmail.com> Dec 20 2011
• Dejan Lekic <dejan.lekic gmail.com> Dec 21 2011
• Somedude <lovelydear mailmetrash.com> Dec 21 2011
• Manfred Nowak <svv1999 hotmail.com> Dec 21 2011

Manfred Nowak <svv1999 hotmail.com> writes:

Just looked at index.html of D and got stuck on

    writeln("Hello World, Reloaded");

    // auto type inference and built-in foreach
    foreach (argc, argv; args)
    {
        // Object Oriented Programming
        auto cl = new CmdLin(argc, argv);
        // Improved typesafe printf
        writeln(cl.argnum, cl.suffix, " arg: ", cl.argv);
        // Automatic or explicit memory management
        delete cl;
    }

With the pipe-syntax of shells ( sh, bash, ...) this five lines could be
written as: 

    "Hello World, Piped" | writeln;
    args | CmdLin | {argnum, suffix, " arg: ", argv} | writeln;

Comments?

-manfred

"Kagamin" <spam here.lot> writes:

Just use perl.

=?ISO-8859-1?Q?Alex_R=F8nne_Petersen?= <xtzgzorex gmail.com> writes:

On 21-12-2011 05:51, Manfred Nowak wrote:
 Just looked at index.html of D and got stuck on

      writeln("Hello World, Reloaded");

      // auto type inference and built-in foreach
      foreach (argc, argv; args)
      {
          // Object Oriented Programming
          auto cl = new CmdLin(argc, argv);
          // Improved typesafe printf
          writeln(cl.argnum, cl.suffix, " arg: ", cl.argv);
          // Automatic or explicit memory management
          delete cl;
      }

 With the pipe-syntax of shells ( sh, bash, ...) this five lines could be
 written as:

      "Hello World, Piped" | writeln;
      args | CmdLin | {argnum, suffix, " arg: ", argv} | writeln;

 Comments?

 -manfred


You could have a look at the pipe template in std.functional. But in 
general, I agree; a sort of piping operator would be very useful in 
algorithmic code. I find myself using the "|>" operator often in F#.

- Alex

Dejan Lekic <dejan.lekic gmail.com> writes:

Perhaps I should think more about it, but right now I am 100% against it, as 
it makes the code extremely unreadable to an imperative programmer.

I will have to become a ~100% functional programmer to understand what all 
those overloaded operators do behind the scenes. To me | is a bitwise OR 
operator, end of story. When I see "|>" and similar in functional languages, 
I get a headache... 
My opinion - we should strive for a good ballance between imperative and 
declarative in D, not to include every possible feature a functional 
language might have.

If you really, really want something like that, then the D way would be to 
use the "~" operator perhaps...

Somedude <lovelydear mailmetrash.com> writes:

Le 21/12/2011 13:54, Dejan Lekic a écrit :
 
 Perhaps I should think more about it, but right now I am 100% against it, as 
 it makes the code extremely unreadable to an imperative programmer.
 
 .... 
 My opinion - we should strive for a good ballance between imperative and 
 declarative in D, not to include every possible feature a functional 
 language might have.
 


of "simplifying" code here and there is a good way to make the code
unreadable.
Even in Python, you can write unreadable code by abusing from functional
syntax. Eventually, Guido van Rossum discourages this kind of writing.

Manfred Nowak <svv1999 hotmail.com> writes:

Dejan Lekic wrote:

 extremely unreadable to an imperative programmer.



 not to include every possible feature a
 functional language might have.



 If you really, really want something like that, then the D way would
 be to use the "~" operator perhaps...


same "history" as `!' in D. 

As Alex points out, another D way seems to be to write something like:
  pipe!( echo!args,
         CmdLin,
         pipe!(argnum, suffix, " arg: ", argv),
         writeln
       );
But I do not see any sugar in this.

-manfred