The Case Against Autodecode

[Steven Schveighoffer via Digitalmars-d]

On 5/13/16 5:25 PM, Alex Parrill wrote:
> On Friday, 13 May 2016 at 16:05:21 UTC, Steven Schveighoffer wrote:
>> On 5/12/16 4:15 PM, Walter Bright wrote:
>>
>>> 10. Autodecoded arrays cannot be RandomAccessRanges, losing a key
>>> benefit of being arrays in the first place.
>>
>> I'll repeat what I said in the other thread.
>>
>> The problem isn't auto-decoding. The problem is hijacking the char[]
>> and wchar[] (and variants) array type to mean autodecoding non-arrays.
>>
>> If you think this code makes sense, then my definition of sane varies
>> slightly from yours:
>>
>> static assert(!hasLength!R && is(typeof(R.init.length)));
>> static assert(!is(ElementType!R == R.init[0]));
>> static assert(!isRandomAccessRange!R && is(typeof(R.init[0])) &&
>> is(typeof(R.init[0 .. $])));
>>
>> I think D would be fine if string meant some auto-decoding struct with
>> an immutable(char)[] array backing. I can accept and work with that. I
>> can transform that into a char[] that makes sense if I have no use for
>> auto-decoding. As of today, I have to use byCodePoint, or
>> .representation, etc. and it's very unwieldy.
>>
>> If I ran D, that's what I would do.
>>
>
> Well, the "auto" part of autodecoding means "automatically doing it for
> plain strings", right? If you explicitly do decoding, I think it would
> just be "decoding"; there's no "auto" part.

No, the problem isn't the auto-decoding. The problem is having *arrays* 
do that. Sometimes.

I would be perfectly fine with a custom string type that all string 
literals were typed as, as long as I can get a sanely behaving array out 
of it.

> I doubt anyone is going to complain if you add in a struct wrapper
> around a string that iterates over code units or graphemes. The issue
> most people have, as you say, is the fact that the default for strings
> is to decode.

I want to clarify that I don't really care if strings by default 
auto-decode. I think that's fine. What I dislike is that 
immutable(char)[] auto-decodes.

-Steve