A gentle critque..

[Kyle Furlong]

Carlos wrote:
> - D is not C++ ... Importance: SIGH
> - D cannot toast bread ... IMPORTANCE: SHOW-TOASTER
> - D cannot prevent idiocy in programmers ... IMPORTANCE: FATAL
> 
> Charlie
> 
> 
> Ben Cooley wrote:
>> There are a few major problems with D that still prevent it from being 
>> practical
>> for use in the real world.
>>
>> I'll just list them and note their importance.  Anything witha
>>
>> - Inability to access C/C++ include files...  Importance:   SHOW-STOPPER
>> --------------------------------------------
>>
>> C++ can do this, D can not.
>>
>> The size, scale, and prevalence of C and C++ libraries and code make 
>> writing
>> wrappers for all of these libraries impractical.  That D can not just 
>> easily
>> include C and C++ headers "as is" gives it a serious and I would 
>> suggest fatal
>> disadvantage vs. C++.
>>
>> C++ out of the box could include C header files, meaning that even 
>> today I have
>> access to the largest possible body of third party libraries and 
>> code.  Binary
>> compatibility with C only is just not good enough.
>>
>> Incompatibility with C++ ABI...              Importance:    SHOW-STOPPER
>> --------------------------------------------
>>
>> Even if you could include C++ headers, you could not interface with 
>> C++ classes.
>> C has abi compatibility with C++, and C++ has ABI compatibility with 
>> C.  C and
>> C++ have more or less abi compatibility with most other systems 
>> (including COM,
>> CORBA).  D intends to be used for system programming, but is 
>> icompatible with
>> the most prevalent existing ABI.
>> Inability to make D code work with C/C++    Importance:    SHOW-STOPPER
>> ---------------------------------------------
>>
>> Likewise, if you write D code, your code exists only in the very small 
>> world of
>> D, and will not be useful to the world outside of the D programming 
>> community.
>> This makes any library or system you might create only marginally 
>> useful, and is
>> a strong disincentive for anybody to actually write code in D for 
>> general public
>> consumption.
>>
>> No support for meta-programming or Macros   Importance:    SHOW-STOPPER
>> ---------------------------------------------
>>
>> Say what you will about the unclean use of macros in C and C++, they are
>> critical for a large set of important functionality that C and C++ 
>> programmers
>> take for granted.  There are many ways to provide hygenic macro 
>> replacesments,
>> true meta programming, or generative programming.  D offers none of 
>> these, and
>> no way to replace the functionality lost using macros.
>>
>> Correct me if I am wrong on this point, but the meta-programming 
>> offered by
>> macro code injection is just not easily replaced by mixins, templates 
>> or other
>> language features.
>>
>> Provides no additional support for safe programming vs. C/C++  
>> Importance: HIGH
>> ---------------------------------------------
>>
>> C# and Java trade incompatibility and the inability to easily 
>> integrate with
>> C/C++ for the additional productivity and security.  D trades 
>> incompatibility
>> for.. incompatibility.  Programming in D is just as unsafe as 
>> programming in C
>> and C++, without the support of Microsoft and other 3rd parties to 
>> provide huge
>> quantities of high level libraries and a powerful integrated 
>> environment.  D is
>> unsafe by design, just as C and C++ were, but the difference is that 
>> this is
>> 2006, and not the 70's, 80's, or 90's.
>>
>> The choice one is left with is to either program in a safe language 
>> and accept
>> the overhead of the JIT, or use C/C++ with it's large existing base of 
>> tools and
>> code other things in C# or Java.  One wonders why this is so, since C# 
>> has
>> unsafe capabilities.. and CSecured offers safe C programming 
>> capabilities.  How
>> long should we have to wait for a safe systems level language.. till 
>> microsoft
>> releases their Singularity project and their Bartok compiler?
>>
>> ------------
>>
>> The first two issues make much of the remaining critique irrelevant.  
>> Once you
>> have a singel showstopper, additional issues don't really make any 
>> difference.
>> However I'll list them anyway.
>>
>> - Inability to integrate with visual studio.  No good IDE.. 
>> Importance...   HIGH
>>
>> - No stable standard.  Importance...  MEDIUM
>>
>> - Difficult to control what is garbage collected and what is not.  
>> Garbage
>> collection performance.  Garbage collection violates C++'s "zero 
>> overhead" rule
>> where any performance overhead is at the programmers explicit 
>> discression.
>> Importance...   MEDIUM
>>
>> - Not open source.    Importance... HIGH
>>
>> - Very small library base.   Importance... HIGH
>>
>> ----------------------------------------------------------
>>
>> A modest suggestion, were I to try to introduce a new language which I 
>> intended
>> to be not only clean and simple, but "popular" and widely used as well 
>> would be
>> to squarely address the first three issues above.
>>
>> C++ provided a translator.  The original versions of C++ were able to 
>> output C
>> code which would compile on any ordinary C compiler.  Likewise, the 
>> idea that C
>> headers could simply be directly included in a C++ language file, and 
>> "it just
>> worked" allows any C code to be used in a C++ program.. a feature that 
>> all C++
>> programmers use today.
>>
>> Finally, C and C++ code code be easily mixed within a single project, 
>> another
>> feature of C++ that is used today.  Since C++ can consume any C 
>> header, and in
>> most cases C can understand the ABI of C++ with the extern "C" {} 
>> wrapper, it's
>> possible to go in both directions.
>>
>> All this being said, I would really like to see a language like D 
>> succeed,
>> because I need the features it has.  But I can't abandon my C and C++ 
>> libraries,
>> and I am not about to commit to coding wrappers for them, nor forgoing 
>> using my
>> current programming environment and debugging tools.  When I adopted 
>> C++ 20
>> years ago, I didn't need to do this.  C++ integrated well with my 
>> tools and
>> existing libs (the exception being the debugger of course).  But 
>> overall it was
>> a good citizen in the overall world of C/C++ code.. it played nicely.  
>> The same
>> can not be said of D, C#, or Java, and D doesn't have the other 
>> benefits of C#
>> or Java.
>>
>> Until D addresses these issues, it will be nothing more than a niche 
>> language
>> offering syntactic cleanliness and interesting features to a few 
>> faithful, but
>> largely ignored by the rest of the programming world.
>>
>>
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Dont be an ass. Ben, please don't be offended, most of us are nice 
people. ;-) ( I still love you Charlie )

-- 
Kyle Furlong // Physics Undergrad, UCSB

"D is going wherever the D community wants it to go." - Walter Bright