FormattedRead hex string

[Jason Spencer]

On Monday, 24 September 2012 at 16:32:45 UTC, monarch_dodra wrote:
> On Monday, 24 September 2012 at 15:05:54 UTC, Jason Spencer 
> wrote:
>> I imagine there's a slick way to do this, but I'm not seeing 
>> it.
>>
>> I have a string of hex digits which I'd like to convert to an 
>> array of 8 ubytes:
>>
>> 0123456789abcdef --> [0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 
>> 0xCD, 0xEF]
<snip>
>> void main(string[] args)
>> {
>>   ubyte[8] b;
>>
>>   formattedRead(args[1], "%(%s%)", &b);
>> }


> I think that you are not supposed to use a static array: If 
> there are not EXACTLY as many array elements as there are 
> parse-able elements, then the formatted read will consider the 
> parse to have failed.

The sample code was just for testing convenience.  In practice 
the string will be conditioned and known to have 16 characters in 
{0-9, a-f}.

>
> Try this, it's what you want, right?
>
> --------
> void main()
> {
>     string s = "ffff fff ff f";
>     ushort[] vals;
>     formattedRead(s, "%(%x %)", &vals);
>     writefln("%(%s - %)", vals);
> }

Not quite.  You've taken the liberty of using a 
delimiter--spaces.  I have to take 16 contiguous, NON-delimited 
hex digits and produce 8 bytes.  So I could read it as a uint64 
(not uint16, as I mistakenly posted before), but then I'd have to 
byte-reverse it.  I could use slicing and do a byte at a time.  I 
just wondered if there were a slick way to get in-place data from 
a contiguous hex string.

Thanks,
Jason