The great compromise of the D standard library

[Bill Baxter]

Bruce Adams wrote:
> Bill Baxter Wrote:
> 
>> Darryl B wrote:
>>> == Quote from Ender KaShae (astrothayne at gmail.com)'s article
>>>> I have great misgivings over the divide among the D community between standard
>>> libriraries.  The contintion will no doubt eventually lead to a  schism reduce the
>>> reusibility of D code.
>>>
>>> I absolutely agree with this point. One of the first eyebrow-raising experiences
>>> for me, moving to D, was learning of this 'alternate' standard library. The 'D'
>>> standard library should be 'the' D standard library, shouldn't it? You may as well
>>> be writing in a different language, going from one lib to the other. You really
>>> have to specify which 'flavor' of D you use when speaking to others, and a Tango
>>> dev may not even want to look at a problem someone has if they were using Phobos.
>>> The separation of the 'D-Tango' and 'D-Phobos' factions is detrimental to the D
>>> language as a whole, IMO.
>> There's also D2.0 which is a completely different, incompatible version 
>> of D.  So really there are *three* different incompatible versions of D 
>> to choose from right now (yes you can get some source code to compile 
>> with both D1 and D2, just like you can get some code to compile with 
>> either Tango or Phobos).
>>
>> I was all for adding of const to D, but my vision was for it to get 
>> added relatively quickly and become the one-and-only D.  Add it quickly, 
>> get everyone to fix their code, and then forget there ever was a D 
>> without const.  Leave it in the dust.  Just like we forgot about D with 
>> regular expression literals, or D with the === operator.
>>
>> But instead we got a D-without-const codified as a permanent, unchanging 
>> standard and D-with-const as a new, incompatible, competing standard.
>>
>> Taking a step back it just seems really silly for a niche language like 
>> D to have so many factions.
>>
>> So here's a little proposal to maybe help mend the D1/D2 schism a bit: 
>> add -v2 compatiblity switch to D1 that would cause it to just ignore 
>> D2's const and invariant declarations.  That would make writing code 
>> that works on both a lot easier.
>>
>> After porting a bit of D2's std.* to D1, it seems that the main issues 
>> are just const(foo)[] and invariant(foo)[] constructs here and there. 
>> The fix is almost always just to remove them.  So if the D1 compiler 
>> could be made to ignore those then that would remove most of the hassle 
>> of making code compatible between D1 and D2.
>>
>> --bb
> 
> Is this really worth the hassle? If you check Walter's recent postings sorting out const is on the list for the next release.  He know's it sucks, he started a thread on it remember. I don't think we have long to wait for the next try. He could get it wrong again but given all the feedback and some time to think maybe he's got it right this time (or at least right enough).

D1.0 is still intended as a long-term support, stable version of D.  So 
D1.0 is not going away for a while even if const turns into everybody's 
favorite feature of D2.0.  And even if the new const design has 
everybody doing backflips of joy, code written using it it will still be 
incompatible with D1.0, and making it compatible will still be a pain 
since D lacks the equivalent of something like
    #define invariant /*nothing*/

--bb