• bearophile (3/3) Feb 29 2012 Do you know why std.array.Appender defines a "put" method instead of ove...
• Jonathan M Davis (3/5) Feb 29 2012 put is a function on output ranges, and Appender is an output range.
• Andrej Mitrovic (2/2) Feb 29 2012 Luckily you can always use alias this and overload opCatAssign. 'alias
• Jonathan M Davis (4/9) Feb 29 2012 Also, given that it doesn't define ~ (and it wouldn't really make sense ...
• bearophile (5/9) Feb 29 2012 I don't understand why that's weird.
• Adam D. Ruppe (7/10) Feb 29 2012 I agree entirely.
• Jonathan M Davis (12/27) Feb 29 2012 True, but it can't do all of the other operations that array can do eith...
• Adam D. Ruppe (13/16) Feb 29 2012 Yeah, but the one operation it replaces, ~=, can be done
• James Miller (16/33) Feb 29 2012 I can see both sides, but I'm on Adam's side here. While all the other
• =?UTF-8?B?QWxpIMOHZWhyZWxp?= (14/19) Feb 29 2012 Yes you can but whatever you put() into the array is immediately
• Jonathan M Davis (5/17) Feb 29 2012 Would you define += without defining +? Or *= without defining *? It str...
• Timon Gehr (2/19) Mar 01 2012 It is not the same thing. a=a~b has different semantics from a~=b;
• =?UTF-8?B?U8O2bmtlIEx1ZHdpZw==?= (2/19) Mar 01 2012 Consider matrix * vector and matrix *= vector for an opposite example.
• Steven Schveighoffer (6/8) Mar 05 2012 It should (in addition to put). I see you have already filed an
• Suliman (9/17) Oct 13 2015 Can I use Appender to add at end of every string my symbol?
• Suliman (3/3) Oct 13 2015 I tried to use map! but it's look like it do not work with
• John Colvin (5/8) Oct 13 2015 I suspect you don't have it imported.
• Suliman (4/12) Oct 13 2015 Thanks, you are right! Can I add with map some element before and
• Suliman (2/2) Oct 13 2015 something like: auto content = file.byLine.map!("start " ~ a=>a ~
• anonymous (3/5) Oct 13 2015 That's not how it works at all. Maybe stick to the examples of whatever
• Suliman (3/8) Oct 13 2015 Yes, I understand that it's not work exactly like I try to use
• anonymous (2/4) Oct 13 2015 Use ~ instead of ~=, like so: map!(a => "+" ~ a ~ "+")
• Suliman (2/6) Oct 13 2015 Thanks!

bearophile <bearophileHUGS lycos.com> writes:

Do you know why std.array.Appender defines a "put" method instead of
overloading the "~=" operator?

Bye and thank you,
bearophile

"Jonathan M Davis" <jmdavisProg gmx.com> writes:

On Wednesday, February 29, 2012 20:25:35 bearophile wrote:
 Do you know why std.array.Appender defines a "put" method instead of
 overloading the "~=" operator?

put is a function on output ranges, and Appender is an output range.

- Jonathan M Davis

Andrej Mitrovic <andrej.mitrovich gmail.com> writes:

Luckily you can always use alias this and overload opCatAssign. 'alias
this' is a great tool for customizing APIs. :)

"Jonathan M Davis" <jmdavisProg gmx.com> writes:

On Wednesday, February 29, 2012 20:53:04 Jonathan M Davis wrote:
 On Wednesday, February 29, 2012 20:25:35 bearophile wrote:
 Do you know why std.array.Appender defines a "put" method instead of
 overloading the "~=" operator?

 
 put is a function on output ranges, and Appender is an output range.

Also, given that it doesn't define ~ (and it wouldn't really make sense for it 
to), it would be very weird IMHO to define ~=.

- Jonathan M Davis

bearophile <bearophileHUGS lycos.com> writes:

Jonathan M Davis:

 put is a function on output ranges, and Appender is an output range.

 
 Also, given that it doesn't define ~ (and it wouldn't really make sense for it 
 to), it would be very weird IMHO to define ~=.

I don't understand why that's weird.
In Java you can't overload an append operator, so using a method is right. But
for me it's weird that Appender doesn't use the D operator to _append_. I
sometimes use "add" instead of "put" by mistake, forgetting the right method
name, because I find it quite unnatural. If Appender needs a put, then I
suggest to give it both "put" method and "~=" operator.

Bye,
bearophile

"Adam D. Ruppe" <destructionator gmail.com> writes:

On Thursday, 1 March 2012 at 02:23:55 UTC, bearophile wrote:
 But for me it's weird that Appender doesn't use the D operator 
 to _append_.  [...] I suggest to give it both "put" method and 
 "~=" operator.

I agree entirely.


Another annoyance is if you have a function that works on
regular arrays, you probably used ~=.

But you decide to switch to Appender to try for a speed boost.

Now you have to change all the usage too, since the interfaces
are incompatible!

Jonathan M Davis <jmdavisProg gmx.com> writes:

On Thursday, March 01, 2012 03:29:06 Adam D. Ruppe wrote:
 On Thursday, 1 March 2012 at 02:23:55 UTC, bearophile wrote:
 But for me it's weird that Appender doesn't use the D operator
 to _append_.  [...] I suggest to give it both "put" method and
 "~=" operator.

 
 I agree entirely.
 
 
 Another annoyance is if you have a function that works on
 regular arrays, you probably used ~=.
 
 But you decide to switch to Appender to try for a speed boost.
 
 Now you have to change all the usage too, since the interfaces
 are incompatible!

True, but it can't do all of the other operations that array can do either. 
It's an output range, not an array. And odds are that it's going to be 
refactored such that it doesn't even contain an array internally anymore, 
beacause that's an inefficient way to implement appending. Someone (Robert 
Jacques IIRC, but I'd have to check) has already created such an 
implementation, and there's a decent chance that it's going to make it into 
Phobos.

So, I'm not sure that treating Appender as an array is really a good idea in 
the first place. If you want the truly generic approach, then treat is an 
output range.

- Jonathan M Davis

"Adam D. Ruppe" <destructionator gmail.com> writes:

On Thursday, 1 March 2012 at 02:44:35 UTC, Jonathan M Davis wrote:
 True, but it can't do all of the other operations that array 
 can do either.

Yeah, but the one operation it replaces, ~=, can be done
on an array.

If you're trying to convert array code to Appender for
speed, most likely you're going to be replacing a
bunch of ~= calls.

It's ok if the other op don't compile, but this one
really should. Appender, regardless of the internal
representation vs array is a speed optimization;
an implementation detail.

 It's an output range, not an array.

It's also an Appender, though. I think it is a little
silly to have an Appender to which you can't /append/.

(put is great too, don't get me wrong, but so is ~=).

James Miller <james aatch.net> writes:

On 1 March 2012 15:49, Adam D. Ruppe <destructionator gmail.com> wrote:
 On Thursday, 1 March 2012 at 02:44:35 UTC, Jonathan M Davis wrote:
 True, but it can't do all of the other operations that array can do
 either.


 Yeah, but the one operation it replaces, ~=, can be done
 on an array.

 If you're trying to convert array code to Appender for
 speed, most likely you're going to be replacing a
 bunch of ~= calls.

 It's ok if the other op don't compile, but this one
 really should. Appender, regardless of the internal
 representation vs array is a speed optimization;
 an implementation detail.


 It's an output range, not an array.


 It's also an Appender, though. I think it is a little
 silly to have an Appender to which you can't /append/.

 (put is great too, don't get me wrong, but so is ~=).

I can see both sides, but I'm on Adam's side here. While all the other
opOpAssign functions are defined in terms of their opBinary equivalent
(e.g, += is 'add and assign'), ~= is essentially an operator in its
own right, specifically an append (as opposed to '~' which is
concatenate). Having both ~= and .put() would be fine, and would make
switching from arrays to Appenders much easier.

I understand that Appenders aren't arrays, and should not be used as
such, but you /can/ use an array as an Appender. At some point, you
have to concede design purity to convenience, otherwise you have a
language that is actively hostile to changing designs. *In best
"nagging wife" voice* "You should have used an Appender from the
start. Now you have to go change all that code. Its your own fault
really."...

--
James Miller

=?UTF-8?B?QWxpIMOHZWhyZWxp?= <acehreli yahoo.com> writes:

On 02/29/2012 08:28 PM, James Miller wrote:

 I understand that Appenders aren't arrays, and should not be used as
 such, but you /can/ use an array as an Appender.

Yes you can but whatever you put() into the array is immediately 
popFront()'ed from the array. ;) You must use a temporary surrogate slice:

import std.stdio;
import std.range;

void main()
{
     int[] array = [ 1, 2, 3 ];
     int[] slice = array;

     put(slice, 100);  // <-- slice shrinks! :)
}

slice.length is 2 and array.length is 3.

 At some point, you
 have to concede design purity to convenience, otherwise you have a
 language that is actively hostile to changing designs.

Agreed.

Ali

Jonathan M Davis <jmdavisProg gmx.com> writes:

On Wednesday, February 29, 2012 21:23:54 bearophile wrote:
 Jonathan M Davis:
 put is a function on output ranges, and Appender is an output range.

 
 Also, given that it doesn't define ~ (and it wouldn't really make sense
 for it to), it would be very weird IMHO to define ~=.

 
 I don't understand why that's weird.
 In Java you can't overload an append operator, so using a method is right.
 But for me it's weird that Appender doesn't use the D operator to _append_.
 I sometimes use "add" instead of "put" by mistake, forgetting the right
 method name, because I find it quite unnatural. If Appender needs a put,
 then I suggest to give it both "put" method and "~=" operator.

Would you define += without defining +? Or *= without defining *? It strikes me 
as a misuse of operator overloading if you have an opOpAssign without its 
corresponding opBinary.

- Jonathan M Davis

Timon Gehr <timon.gehr gmx.ch> writes:

On 03/01/2012 03:40 AM, Jonathan M Davis wrote:
 On Wednesday, February 29, 2012 21:23:54 bearophile wrote:
 Jonathan M Davis:
 put is a function on output ranges, and Appender is an output range.

 Also, given that it doesn't define ~ (and it wouldn't really make sense
 for it to), it would be very weird IMHO to define ~=.

 I don't understand why that's weird.
 In Java you can't overload an append operator, so using a method is right.
 But for me it's weird that Appender doesn't use the D operator to _append_.
 I sometimes use "add" instead of "put" by mistake, forgetting the right
 method name, because I find it quite unnatural. If Appender needs a put,
 then I suggest to give it both "put" method and "~=" operator.

 Would you define += without defining +? Or *= without defining *? It strikes me
 as a misuse of operator overloading if you have an opOpAssign without its
 corresponding opBinary.

 - Jonathan M Davis

It is not the same thing. a=a~b has different semantics from a~=b;

=?UTF-8?B?U8O2bmtlIEx1ZHdpZw==?= <ludwig informatik.uni-luebeck.de> writes:

Am 01.03.2012 03:40, schrieb Jonathan M Davis:
 On Wednesday, February 29, 2012 21:23:54 bearophile wrote:
 Jonathan M Davis:
 put is a function on output ranges, and Appender is an output range.

 Also, given that it doesn't define ~ (and it wouldn't really make sense
 for it to), it would be very weird IMHO to define ~=.

 I don't understand why that's weird.
 In Java you can't overload an append operator, so using a method is right.
 But for me it's weird that Appender doesn't use the D operator to _append_.
 I sometimes use "add" instead of "put" by mistake, forgetting the right
 method name, because I find it quite unnatural. If Appender needs a put,
 then I suggest to give it both "put" method and "~=" operator.

 Would you define += without defining +? Or *= without defining *? It strikes me
 as a misuse of operator overloading if you have an opOpAssign without its
 corresponding opBinary.

 - Jonathan M Davis

Consider matrix * vector and matrix *= vector for an opposite example.

"Steven Schveighoffer" <schveiguy yahoo.com> writes:

On Wed, 29 Feb 2012 20:25:35 -0500, bearophile <bearophileHUGS lycos.com>  
wrote:

 Do you know why std.array.Appender defines a "put" method instead of  
 overloading the "~=" operator?

It should (in addition to put).  I see you have already filed an  
enhancement.

http://d.puremagic.com/issues/show_bug.cgi?id=4287

-Steve

Suliman <evermind live.ru> writes:

On Monday, 5 March 2012 at 15:35:59 UTC, Steven Schveighoffer 
wrote:
 On Wed, 29 Feb 2012 20:25:35 -0500, bearophile 
 <bearophileHUGS lycos.com> wrote:

 Do you know why std.array.Appender defines a "put" method 
 instead of overloading the "~=" operator?

 It should (in addition to put).  I see you have already filed 
 an enhancement.

 http://d.puremagic.com/issues/show_bug.cgi?id=4287

 -Steve

Can I use Appender to add at end of every string my symbol?

	foreach (pointsfile; pointsFiles)
	{
		File file = File(pointsfile, "r");
		string content = file.byLine; // I need to add "+" at at end of 
every string
	}

Suliman <evermind live.ru> writes:

I tried to use map! but it's look like it do not work with 
string, becouse I got error: Error: no property 'map' for type 
'ByLine!(char, char)'

John Colvin <john.loughran.colvin gmail.com> writes:

On Tuesday, 13 October 2015 at 13:21:54 UTC, Suliman wrote:
 I tried to use map! but it's look like it do not work with 
 string, becouse I got error: Error: no property 'map' for type 
 'ByLine!(char, char)'

I suspect you don't have it imported.

import std.algorithm;

or

import std.algorithm : map;

Suliman <evermind live.ru> writes:

On Tuesday, 13 October 2015 at 13:34:02 UTC, John Colvin wrote:
 On Tuesday, 13 October 2015 at 13:21:54 UTC, Suliman wrote:
 I tried to use map! but it's look like it do not work with 
 string, becouse I got error: Error: no property 'map' for type 
 'ByLine!(char, char)'

 I suspect you don't have it imported.

 import std.algorithm;

 or

 import std.algorithm : map;

Thanks, you are right! Can I add with map some element before and 
after string? map!(a=> a~=" +") work fine, but how to add before 
at same time?

Suliman <evermind live.ru> writes:

something like: auto content = file.byLine.map!("start " ~ a=>a ~ 
" end");

anonymous <anonymous example.com> writes:

On Tuesday 13 October 2015 15:47, Suliman wrote:

 something like: auto content = file.byLine.map!("start " ~ a=>a ~ 
 " end");

That's not how it works at all. Maybe stick to the examples of whatever 
resource you're learning from, for now.

Suliman <evermind live.ru> writes:

On Tuesday, 13 October 2015 at 13:55:07 UTC, anonymous wrote:
 On Tuesday 13 October 2015 15:47, Suliman wrote:

 something like: auto content = file.byLine.map!("start " ~ 
 a=>a ~ " end");

 That's not how it works at all. Maybe stick to the examples of 
 whatever resource you're learning from, for now.

Yes, I understand that it's not work exactly like I try to use 
it, but which function can solve my problem?

anonymous <anonymous example.com> writes:

On Tuesday 13 October 2015 15:42, Suliman wrote:

 map!(a=> a~=" +") work fine, but how to add before 
 at same time?

Use ~ instead of ~=, like so: map!(a => "+" ~ a ~ "+")

Suliman <evermind live.ru> writes:

On Tuesday, 13 October 2015 at 13:51:50 UTC, anonymous wrote:
 On Tuesday 13 October 2015 15:42, Suliman wrote:

 map!(a=> a~=" +") work fine, but how to add before at same 
 time?

 Use ~ instead of ~=, like so: map!(a => "+" ~ a ~ "+")

Thanks!