www.digitalmars.com         C & C++   DMDScript  

digitalmars.D.learn - Is autodecoding being phased out?

reply Dukc <ajieskola gmail.com> writes:
I (finally) managed to build the development build of dmd, with 
libraries. When testing if it compiles a Hello World program (it 
does, no problem) I got these messages:

C:\D\dmd2\windows\bin\..\..\src\phobos\std\stdio.d(2716,24): 
Deprecation: function std.utf.toUTF8 is deprecated - To be 
removed November 2017. Please use std.utf.encode instead.
C:\D\dmd2\windows\bin\..\..\src\phobos\std\stdio.d(2716,24): 
Deprecation: function std.utf.toUTF8 is deprecated - To be 
removed November 2017. Please use std.utf.encode instead.
C:\D\dmd2\windows\bin\..\..\src\phobos\std\stdio.d(2727,40): 
Deprecation: function std.utf.toUTF8 is deprecated - To be 
removed November 2017. Please use std.utf.encode instead.

If I output a dstring instead, those messages vanish. Does that 
mean we're getting rid of autodecoding?

If that's the case, have nothing against that. In fact it is nice 
to have that deprecation to catch bugs. I just thought, due to an 
earlier forum discussion, that it's not going to happen because 
it could break too much code. That's why I'm asking...
Feb 21 2017
next sibling parent Seb <seb wilzba.ch> writes:
On Tuesday, 21 February 2017 at 14:46:10 UTC, Dukc wrote:

 I (finally) managed to build the development build of dmd, with 
 libraries. When testing if it compiles a Hello World program 
 (it does, no problem) I got these messages:

 C:\D\dmd2\windows\bin\..\..\src\phobos\std\stdio.d(2716,24): 
 Deprecation: function std.utf.toUTF8 is deprecated - To be 
 removed November 2017. Please use std.utf.encode instead.
 C:\D\dmd2\windows\bin\..\..\src\phobos\std\stdio.d(2716,24): 
 Deprecation: function std.utf.toUTF8 is deprecated - To be 
 removed November 2017. Please use std.utf.encode instead.
 C:\D\dmd2\windows\bin\..\..\src\phobos\std\stdio.d(2727,40): 
 Deprecation: function std.utf.toUTF8 is deprecated - To be 
 removed November 2017. Please use std.utf.encode instead.

 If I output a dstring instead, those messages vanish. Does that 
 mean we're getting rid of autodecoding?


Sadly no. Just of old pre auto-decoding code.


 If that's the case, have nothing against that. In fact it is 
 nice to have that deprecation to catch bugs. I just thought, 
 due to an earlier forum discussion, that it's not going to 
 happen because it could break too much code. That's why I'm 
 asking...


No - this is just a deprecation of a specific overload of toUTF8.
See this PR for details:

https://github.com/dlang/phobos/pull/5083

However, this deprecation warning was fixed subsequently in:

https://github.com/dlang/phobos/pull/5143

So are you on LATEST? ;-)
Feb 21 2017
prev sibling next sibling parent reply Jonathan M Davis via Digitalmars-d-learn writes:
On Tuesday, February 21, 2017 14:46:10 Dukc via Digitalmars-d-learn wrote:

 I (finally) managed to build the development build of dmd, with
 libraries. When testing if it compiles a Hello World program (it
 does, no problem) I got these messages:

 C:\D\dmd2\windows\bin\..\..\src\phobos\std\stdio.d(2716,24):
 Deprecation: function std.utf.toUTF8 is deprecated - To be
 removed November 2017. Please use std.utf.encode instead.
 C:\D\dmd2\windows\bin\..\..\src\phobos\std\stdio.d(2716,24):
 Deprecation: function std.utf.toUTF8 is deprecated - To be
 removed November 2017. Please use std.utf.encode instead.
 C:\D\dmd2\windows\bin\..\..\src\phobos\std\stdio.d(2727,40):
 Deprecation: function std.utf.toUTF8 is deprecated - To be
 removed November 2017. Please use std.utf.encode instead.

 If I output a dstring instead, those messages vanish. Does that
 mean we're getting rid of autodecoding?

 If that's the case, have nothing against that. In fact it is nice
 to have that deprecation to catch bugs. I just thought, due to an
 earlier forum discussion, that it's not going to happen because
 it could break too much code. That's why I'm asking...


Well, hello world shouldn't be printing deprecation messages, so something
needs to be fixed. But the only version of std.utf.toUTF8 that's being
deprecated is the version that takes a static array, because it does the
same thing as std.utf.encode. So, aside from the fact that something in
Phobos apparently needs to be updated to not use that overload of toUTF8, it
probably doesn't affect you.

Certainly, as it stands, auto-decoding is not going to be phased out - if
nothing else because we don't have a clean way to do it. The code is slowly
being improved so that it works with general character ranges, and stuff
like byCodeUnit has been added, so less in Phobos relies on autodecoding,
and we have better ways to avoid it, but to actually remove it such that
str.front and str.popFront don't auto-decode would break code, and no one
has come up with a way to make the necessary changes without breaking code.

Andrei wants to add RCString (or whatever it's going to be called) which
would then be a reference counted string with small string optimizations and
push for that to be used as the typical string type for code to use, and it
wouldn't do autodecoding. So, maybe at some point, a lot of strings being
used in D code won't autodecode, but as it stands, it's looking like we're
permanently screwed with regards to arrays of char and wchar.

Maybe once enough of Phobos has been fixed to work with arbitrary ranges of
characters, we can find a way to force the transition, but I doubt it.

- Jonathan M Davis
Feb 21 2017
parent Dukc <ajieskola gmail.com> writes:
On Tuesday, 21 February 2017 at 15:24:18 UTC, Jonathan M Davis 
wrote:

 [snip]
 - Jonathan M Davis


Thanks for the in-depth answer. Well, auto-decoding is an 
annoyance but not that bad, I can live with it.
Feb 21 2017
prev sibling parent "H. S. Teoh via Digitalmars-d-learn" <digitalmars-d-learn puremagic.com> writes:
On Tue, Feb 21, 2017 at 02:46:10PM +0000, Dukc via Digitalmars-d-learn wrote:

 I (finally) managed to build the development build of dmd, with
 libraries.  When testing if it compiles a Hello World program (it
 does, no problem) I got these messages:
 
 C:\D\dmd2\windows\bin\..\..\src\phobos\std\stdio.d(2716,24): Deprecation:
 function std.utf.toUTF8 is deprecated - To be removed November 2017. Please
 use std.utf.encode instead.
 C:\D\dmd2\windows\bin\..\..\src\phobos\std\stdio.d(2716,24): Deprecation:
 function std.utf.toUTF8 is deprecated - To be removed November 2017. Please
 use std.utf.encode instead.
 C:\D\dmd2\windows\bin\..\..\src\phobos\std\stdio.d(2727,40): Deprecation:
 function std.utf.toUTF8 is deprecated - To be removed November 2017. Please
 use std.utf.encode instead.
 
 If I output a dstring instead, those messages vanish. Does that mean
 we're getting rid of autodecoding?
 
 If that's the case, have nothing against that. In fact it is nice to
 have that deprecation to catch bugs. I just thought, due to an earlier
 forum discussion, that it's not going to happen because it could break
 too much code. That's why I'm asking...


Do another git update.  This is a transitory issue where std.stdio got a
bit out-of-sync with std.utf, but this deprecation message should no
longer appear in the latest git HEAD.  (I also saw the same messages and
was about to submit a PR, but after updating my git repos they went
away.)


T

-- 
Unix was not designed to stop people from doing stupid things, because that
would also stop them from doing clever things. -- Doug Gwyn
Feb 21 2017