On 9/6/11 4:52 PM, Jonathan M Davis wrote:
> On Tuesday, September 06, 2011 17:03:30 Nick Sabalausky wrote:
>> The names inside std.system.Endian were changed from UpperCamelCase to
>> lowerCamelCase, which makes sense, but maybe the old names should still
>> exist for migration?
>
> Yu can't rename enum values without breaking code. Any final switches would be
> broken if you left in the old values as would anything using
> std.traits.EnumMembers.

I think EnumMembers is used rarely enough to not warrant much worry. If 
final switch fails to compile because it doesn't handle all aliases of 
the same value, that's a bug in the compiler. So I think keeping old 
values alongside new ones is good practice.

> A simple renaming is caught and pointed out quite well
> by the compiler's spellchecker.

Code breakage is what it is.


Andrei

On 9/7/11, Andrei Alexandrescu <andrei at erdani.com> wrote:
> I think EnumMembers is used rarely enough to not warrant much worry.

O.T. but EnumMembers is great for testing purposes. I've recently used
it to test various drawing methods which are selected at compile-time
via an enum argument, snippet below:

foreach (index, method; EnumMembers!RoundMethod)
{
   roundedRectangle!(method)(ctx, index * xPos, 0, 100, 100, 10, 10);
   ctx.fill();
}

results: http://i.imgur.com/hTuGl.png

On Tuesday, September 06, 2011 17:01:28 Andrei Alexandrescu wrote:
> On 9/6/11 4:52 PM, Jonathan M Davis wrote:
> > On Tuesday, September 06, 2011 17:03:30 Nick Sabalausky wrote:
> >> The names inside std.system.Endian were changed from UpperCamelCase to
> >> lowerCamelCase, which makes sense, but maybe the old names should
> >> still
> >> exist for migration?
> > 
> > Yu can't rename enum values without breaking code. Any final switches
> > would be broken if you left in the old values as would anything using
> > std.traits.EnumMembers.
> 
> I think EnumMembers is used rarely enough to not warrant much worry. If
> final switch fails to compile because it doesn't handle all aliases of
> the same value, that's a bug in the compiler. So I think keeping old
> values alongside new ones is good practice.

I don't know how rare EnumMembers usage is, but it's definitely used. I use it 
in unit tests and the like. It's probably not a big issue for 
std.system.Endian though. Regardless, it was discussed in the pull request. I 
said that I hadn't provided duplicate enum values with the old names, and you 
merged it in that way.

> > A simple renaming is caught and pointed out quite well
> > by the compiler's spellchecker.
> 
> Code breakage is what it is.

True. But this is easy-to-fix code breakage. My point is that you _can't_ avoid 
code breakage when renaming enums. It's just a question of what code you're 
going to break, how easy such breakage is going to fix, and how common it is. 
Renamings are going to be more common but very easy to fix. Something like 
EnumMembers may be less common, but it's going to be more subtle when it 
breaks, and the code which uses it would have to be changed to explicitly 
ignore duplicate enum values, which could be problematic.

- Jonathan M Davis

On 9/6/11 5:16 PM, Jonathan M Davis wrote:
> On Tuesday, September 06, 2011 17:01:28 Andrei Alexandrescu wrote:
>> On 9/6/11 4:52 PM, Jonathan M Davis wrote:
>>> On Tuesday, September 06, 2011 17:03:30 Nick Sabalausky wrote:
>>>> The names inside std.system.Endian were changed from UpperCamelCase to
>>>> lowerCamelCase, which makes sense, but maybe the old names should
>>>> still
>>>> exist for migration?
>>>
>>> Yu can't rename enum values without breaking code. Any final switches
>>> would be broken if you left in the old values as would anything using
>>> std.traits.EnumMembers.
>>
>> I think EnumMembers is used rarely enough to not warrant much worry. If
>> final switch fails to compile because it doesn't handle all aliases of
>> the same value, that's a bug in the compiler. So I think keeping old
>> values alongside new ones is good practice.
>
> I don't know how rare EnumMembers usage is, but it's definitely used. I use it
> in unit tests and the like. It's probably not a big issue for
> std.system.Endian though. Regardless, it was discussed in the pull request. I
> said that I hadn't provided duplicate enum values with the old names, and you
> merged it in that way.

Doesn't mean we're sworn into that, and now that the problem was raised 
by a second person, I thought I'd put it back on the plate.

>>> A simple renaming is caught and pointed out quite well
>>> by the compiler's spellchecker.
>>
>> Code breakage is what it is.
>
> True. But this is easy-to-fix code breakage. My point is that you _can't_ avoid
> code breakage when renaming enums. It's just a question of what code you're
> going to break, how easy such breakage is going to fix, and how common it is.
> Renamings are going to be more common but very easy to fix. Something like
> EnumMembers may be less common, but it's going to be more subtle when it
> breaks, and the code which uses it would have to be changed to explicitly
> ignore duplicate enum values, which could be problematic.

I don't quite buy into this all. Anyway, perhaps an EnumDistinctMembers 
abstraction would be the best outcome of this discussion.


Andrei

On Tuesday, September 06, 2011 17:24:42 Andrei Alexandrescu wrote:
> On 9/6/11 5:16 PM, Jonathan M Davis wrote:
> > On Tuesday, September 06, 2011 17:01:28 Andrei Alexandrescu wrote:
> >> On 9/6/11 4:52 PM, Jonathan M Davis wrote:
> >>> On Tuesday, September 06, 2011 17:03:30 Nick Sabalausky wrote:
> >>>> The names inside std.system.Endian were changed from
> >>>> UpperCamelCase to
> >>>> lowerCamelCase, which makes sense, but maybe the old names should
> >>>> still
> >>>> exist for migration?
> >>> 
> >>> Yu can't rename enum values without breaking code. Any final
> >>> switches
> >>> would be broken if you left in the old values as would anything
> >>> using
> >>> std.traits.EnumMembers.
> >> 
> >> I think EnumMembers is used rarely enough to not warrant much worry.
> >> If
> >> final switch fails to compile because it doesn't handle all aliases of
> >> the same value, that's a bug in the compiler. So I think keeping old
> >> values alongside new ones is good practice.
> > 
> > I don't know how rare EnumMembers usage is, but it's definitely used. I
> > use it in unit tests and the like. It's probably not a big issue for
> > std.system.Endian though. Regardless, it was discussed in the pull
> > request. I said that I hadn't provided duplicate enum values with the
> > old names, and you merged it in that way.
> 
> Doesn't mean we're sworn into that, and now that the problem was raised
> by a second person, I thought I'd put it back on the plate.

I'm just saying that it was discussed before and that you were involved in it. 
If we want to revisit it, we can.

> >>> A simple renaming is caught and pointed out quite well
> >>> by the compiler's spellchecker.
> >> 
> >> Code breakage is what it is.
> > 
> > True. But this is easy-to-fix code breakage. My point is that you
> > _can't_ avoid code breakage when renaming enums. It's just a question
> > of what code you're going to break, how easy such breakage is going to
> > fix, and how common it is. Renamings are going to be more common but
> > very easy to fix. Something like EnumMembers may be less common, but
> > it's going to be more subtle when it breaks, and the code which uses it
> > would have to be changed to explicitly ignore duplicate enum values,
> > which could be problematic.
> 
> I don't quite buy into this all. Anyway, perhaps an EnumDistinctMembers
> abstraction would be the best outcome of this discussion.

That may very well be a good idea. I'm just saying that there _will_ be code 
breakage from changing enum values pretty much no matter what you do. It's 
just a question of the nature of the breakage and what the pros and cons of 
going with one type of breakage over another are.

- Jonathan M Davis

Also, I would point out that because you can't deprecate enum values, the only 
deprecation path is to have to have soft migration followed by removal. So, I 
don't know how much code breakage you're really saving by leaving the old enum 
values in temporarily. We can still do it, but the deprecated keyword and 
whatever it brings to the table can't be involved in the process, because you 
can't put attributes on enum values.

Fortunately, there weren't all that many enum values in Phobos which didn't 
follow the correct naming conventions outside of std.socket, and after this 
release, the only enum values with incorrect names should be the ones in 
std.socket, which looks like it's probably going to be revamped anyway.

- Jonathan M Davis

Probably a good idea would be to enhance the language to allow 
"deprecated" in front of single enum values:

enum Test
{
   a,
   deprecated b,
   c
}

At this point we should pay a great deal of attention to this language 
feature.


Andrei

On 9/6/11 5:39 PM, Jonathan M Davis wrote:
> Also, I would point out that because you can't deprecate enum values, the only
> deprecation path is to have to have soft migration followed by removal. So, I
> don't know how much code breakage you're really saving by leaving the old enum
> values in temporarily. We can still do it, but the deprecated keyword and
> whatever it brings to the table can't be involved in the process, because you
> can't put attributes on enum values.
>
> Fortunately, there weren't all that many enum values in Phobos which didn't
> follow the correct naming conventions outside of std.socket, and after this
> release, the only enum values with incorrect names should be the ones in
> std.socket, which looks like it's probably going to be revamped anyway.
>
> - Jonathan M Davis
> _______________________________________________
> dmd-beta mailing list
> dmd-beta at puremagic.com
> http://lists.puremagic.com/mailman/listinfo/dmd-beta

On Tuesday, September 06, 2011 17:44:04 Andrei Alexandrescu wrote:
> Probably a good idea would be to enhance the language to allow
> "deprecated" in front of single enum values:
> 
> enum Test
> {
>     a,
>     deprecated b,
>     c
> }
> 
> At this point we should pay a great deal of attention to this language
> feature.

It sounds like a good improvement to me. deprecated does need a bit of an 
overhaul (as discussed in https://github.com/D-Programming-
Language/dmd/pull/345 ). I believe that you said in another post recently that 
you had some good ideas about that, and I look forward to you posting them.

- Jonathan M Davis

On 9/6/2011 2:23 PM, Nick Sabalausky wrote:
> The RDMD included in the beta hasn't been rebuilt from latest HEAD. It's still 
> old and is missing some critical bugfixes that are already in HEAD.
>

On which platform?

I was talking specifically about changelog.dd in the DMD repo [1], which 
does not have entries for 2.054 and the soon-to-be 2.055, whereas the 
files in the druntime and Phobos root directories at least seem to be up 
to date.

You seem to be updating the file in  the d-p-l.org repo directly ? which 
one should be used in the future?

David


[1] 
https://github.com/D-Programming-Language/dmd/blob/3da0a36698/changelog.dd


On 9/6/11 8:23 AM, Walter Bright wrote:
> There's a whole section on 2.054 - what is missing?
>
> On 9/5/2011 8:03 PM, David Nadlinger wrote:
>> On 9/6/11 1:52 AM, Walter Bright wrote:
>>> http://ftp.digitalmars.com/dmd1beta.zip
>>> http://ftp.digitalmars.com/dmd2beta.zip
>>
>> Sorry for being a bit on the slow side, but again a question
>> concerning the changelogs: changelog.dd in the DMD repo is missing the
>> entries for 2.054, so the DMD changelog is kept directly in the
>> d-p-l.org repo? Should I submit a pull request for the DMD bugs I
>> fixed, or do you take care of compiling the list, Walter?
>>
>> David
>> _______________________________________________
>> dmd-beta mailing list
>> dmd-beta at puremagic.com
>> http://lists.puremagic.com/mailman/listinfo/dmd-beta
>>
>>
> _______________________________________________
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