digitalmars.D.learn - custom opCmp for array sort

New (41/41) Nov 28 2008 Hello,

New (5/61) Nov 28 2008 Small correction, the code I posted works with D1.0 but not with D2.0. ...
Kagamin (2/2) Nov 28 2008 just found it accidentally

Gide Nwawudu (39/41) Nov 29 2008 Yep, this issue prevents Path.opCmp from being called. The version

New (3/54) Dec 01 2008 Thanks very much indeed for your help. The version posted does work. Unf...

Bill Baxter (4/58) Dec 01 2008 D1 is pretty stable, and I'm pretty sure that's what most folks are
bearophile (4/5) Dec 03 2008 Tell your management that you have used the D2 language that is in alpha...

New <d-devel here.com> writes:

Hello,

I originally posted this question to the wrong group, I am trying here as
suggested.

I am new with D and am stuck with something I hope somebody can help me with it.
I am trying sort an array of paths which can take the two following forms:

/usr                ---> normal path
/bin=/other/bin     ---> a symlink

When I sort these paths, in the case of symlinks I want to ignore the right
hand side and I just use the path before the "=" sign.

The array docs for DMD 2.0, say that can create a structure and create a opCmp
function to cutomise the way sort works. I have tried this but calling .sort
does not seem to pick-up my custom opCmp.

Any help would be very appreciated. I am including the code below

Thanks a lot
--------------------------------------------------------------------
Code cleaned up in d.lang group (my code was a bit messy)

import std.string: find, cmp;
import std.stdio: writefln;

struct Path {
  string thePath;

  int opCmp(Path other) {
    int pos;
    string a, b;

    pos = find(this.thePath, "=");
    if (pos > -1)
      a = this.thePath[0 .. pos];
    else
      a = this.thePath;

    pos = find(other.thePath, "=");
    if (pos > -1)
      b = other.thePath[0 .. pos];
    else
      b = other.thePath;

    return cmp(a, b);
  }
}

void main() {
  string[][Path] contents = [
    Path("/BBB=/other_dir"): ["aa","bb","cc","dd"],
    Path("/AAA"): ["aa","bb","cc","dd"],
    Path("/BB2=/hello") : ["aa","bb","cc","dd"]
                            ];

  foreach (item; contents.keys.sort)
    writefln(item.thePath);
}

Nov 28 2008

New <d-devel here.com> writes:

Small correction, the code I posted works with  D1.0 but not with D2.0. What do
I need to change to make it work with D 2.0?

is it better to use D 2 or D 1? 

sorry for crossposting, I started my questions on the D group but I was
instructed to ask here.


thanks


New Wrote:

 Hello,
 
 I originally posted this question to the wrong group, I am trying here as
suggested.
 
 I am new with D and am stuck with something I hope somebody can help me with
it.
 I am trying sort an array of paths which can take the two following forms:
 
 /usr                ---> normal path
 /bin=/other/bin     ---> a symlink
 
 When I sort these paths, in the case of symlinks I want to ignore the right
hand side and I just use the path before the "=" sign.
 
 The array docs for DMD 2.0, say that can create a structure and create a opCmp
function to cutomise the way sort works. I have tried this but calling .sort
does not seem to pick-up my custom opCmp.
 
 Any help would be very appreciated. I am including the code below
 
 Thanks a lot
 --------------------------------------------------------------------
 Code cleaned up in d.lang group (my code was a bit messy)
 
 import std.string: find, cmp;
 import std.stdio: writefln;
 
 struct Path {
   string thePath;
 
   int opCmp(Path other) {
     int pos;
     string a, b;
 
     pos = find(this.thePath, "=");
     if (pos > -1)
       a = this.thePath[0 .. pos];
     else
       a = this.thePath;
 
     pos = find(other.thePath, "=");
     if (pos > -1)
       b = other.thePath[0 .. pos];
     else
       b = other.thePath;
 
     return cmp(a, b);
   }
 }
 
 void main() {
   string[][Path] contents = [
     Path("/BBB=/other_dir"): ["aa","bb","cc","dd"],
     Path("/AAA"): ["aa","bb","cc","dd"],
     Path("/BB2=/hello") : ["aa","bb","cc","dd"]
                             ];
 
   foreach (item; contents.keys.sort)
     writefln(item.thePath);
 }

Nov 28 2008

Kagamin <spam here.lot> writes:

just found it accidentally
http://d.puremagic.com/issues/show_bug.cgi?id=1309

Nov 28 2008

Gide Nwawudu <gide btinternet.com> writes:

On Fri, 28 Nov 2008 13:58:28 -0500, Kagamin <spam here.lot> wrote:

just found it accidentally
http://d.puremagic.com/issues/show_bug.cgi?id=1309

Yep, this issue prevents Path.opCmp from being called. The version
below works.


import std.string: find, cmp;
import std.stdio: writefln;
import std.algorithm : sort;

struct Path {
    string thePath;

    int opCmp(Path other) {
    	writefln("Path.opCmp");
        int pos;
        string a, b;

        pos = find(this.thePath, "=");
        if (pos > -1)
            a = this.thePath[0 .. pos];
        else
            a = this.thePath;

        pos = find(other.thePath, "=");
        if (pos > -1)
            b = other.thePath[0 .. pos];
        else
            b = other.thePath;

        return cmp(a, b);
    }
}

void main() {
    string[][Path] contents = [
        Path("/002=/other_dir"): ["aa","bb","cc","dd"],
        Path("/001"): ["aa","bb","cc","dd"],
        Path("/002=/hello") : ["aa","bb","cc","dd"]
    ];
    
    Path[] myPaths = contents.keys.dup;
    //myPaths.sort; // Does not call Path.opCmp
    sort(myPaths); // calls Path.opCmp
	
    foreach (item; myPaths)
        writefln(item.thePath);
}

Nov 29 2008

New <here nowhere.net> writes:

Thanks very much indeed for your help. The version posted does work.
Unfortunately I won't be able to use D for my project, this bug has scared the
management, D is still a moving target. I will have to wait until it is more
stable.

Cheers.


Gide Nwawudu Wrote:

 On Fri, 28 Nov 2008 13:58:28 -0500, Kagamin <spam here.lot> wrote:
 
just found it accidentally
http://d.puremagic.com/issues/show_bug.cgi?id=1309

 
 Yep, this issue prevents Path.opCmp from being called. The version
 below works.
 
 
 import std.string: find, cmp;
 import std.stdio: writefln;
 import std.algorithm : sort;
 
 struct Path {
     string thePath;
 
     int opCmp(Path other) {
     	writefln("Path.opCmp");
         int pos;
         string a, b;
 
         pos = find(this.thePath, "=");
         if (pos > -1)
             a = this.thePath[0 .. pos];
         else
             a = this.thePath;
 
         pos = find(other.thePath, "=");
         if (pos > -1)
             b = other.thePath[0 .. pos];
         else
             b = other.thePath;
 
         return cmp(a, b);
     }
 }
 
 void main() {
     string[][Path] contents = [
         Path("/002=/other_dir"): ["aa","bb","cc","dd"],
         Path("/001"): ["aa","bb","cc","dd"],
         Path("/002=/hello") : ["aa","bb","cc","dd"]
     ];
     
     Path[] myPaths = contents.keys.dup;
     //myPaths.sort; // Does not call Path.opCmp
     sort(myPaths); // calls Path.opCmp
 	
     foreach (item; myPaths)
         writefln(item.thePath);
 }

Dec 01 2008

"Bill Baxter" <wbaxter gmail.com> writes:

On Mon, Dec 1, 2008 at 7:23 PM, New <here nowhere.net> wrote:
 Thanks very much indeed for your help. The version posted does work.
Unfortunately I won't be able to use D for my project, this bug has scared the
management, D is still a moving target. I will have to wait until it is more
stable.

D1 is pretty stable, and I'm pretty sure that's what most folks are
using these days, actually.

--bb


 Cheers.


 Gide Nwawudu Wrote:

 On Fri, 28 Nov 2008 13:58:28 -0500, Kagamin <spam here.lot> wrote:

just found it accidentally
http://d.puremagic.com/issues/show_bug.cgi?id=1309

 Yep, this issue prevents Path.opCmp from being called. The version
 below works.


 import std.string: find, cmp;
 import std.stdio: writefln;
 import std.algorithm : sort;

 struct Path {
     string thePath;

     int opCmp(Path other) {
       writefln("Path.opCmp");
         int pos;
         string a, b;

         pos = find(this.thePath, "=");
         if (pos > -1)
             a = this.thePath[0 .. pos];
         else
             a = this.thePath;

         pos = find(other.thePath, "=");
         if (pos > -1)
             b = other.thePath[0 .. pos];
         else
             b = other.thePath;

         return cmp(a, b);
     }
 }

 void main() {
     string[][Path] contents = [
         Path("/002=/other_dir"): ["aa","bb","cc","dd"],
         Path("/001"): ["aa","bb","cc","dd"],
         Path("/002=/hello") : ["aa","bb","cc","dd"]
     ];

     Path[] myPaths = contents.keys.dup;
     //myPaths.sort; // Does not call Path.opCmp
     sort(myPaths); // calls Path.opCmp

     foreach (item; myPaths)
         writefln(item.thePath);
 }

Dec 01 2008

bearophile <bearophileHUGS lycos.com> writes:

New:
 Thanks very much indeed for your help. The version posted does work.
Unfortunately I won't be able to use D for my project, this bug has scared the
management, D is still a moving target. I will have to wait until it is more
stable.

Tell your management that you have used the D2 language that is in alpha stage
still, instead of the D1 that is more stable.

Bye,
bearophile

Dec 03 2008

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digitalmars.D.learn - custom opCmp for array sort