Removal of implicit variable "length"

[kris]

Bradley Smith wrote:
> Jarrett Billingsley wrote:
> 
>> Have you heard of $ ?
>>
>> bar = foo[0 .. $];
> 
> 
> I did notice the mention of "$" in the old newsgroup thread. However, I 
> can't find any official documentation on it.
> 
> 
>> Additionally, try turning on warnings for your original code, and 
>> you'll notice you get one.
> 
> 
> Thanks for pointing out the warnings. I wasn't aware of that warning. 
> Because libraries often cause many warnings, I don't regularly have 
> warning turned on.
> 
> 
>> How about things like
>>
>> int[] x = ALongClassName.AnotherClassName.aNonTrivialOperation()[1 .. $];
>>
>> It's certainly nice to have a shortcut in cases like this, when typing 
>> out the original expression is not only prohibitively long, but could 
>> possibly waste performance re-evaluating the reference to the array.
> 
> 
> Why not the following?
> 
> int[] ref = ALongClassName.AnotherClassName.aNonTrivialOperation();
> int[] x = ref[1 .. ref.length];
> 
> Or perhaps?
> 
> int[] x = ALongClassName.AnotherClassName.aNonTrivialOperation();
> x = x[1 .. x.length];

The original reason, IIRC, was with regard to using arrays + templates, 
where it's not always so easy to leverage temps. However, that orignal 
change brought us the maligned x[0..length] and its special cases. Took 
a long time (a year, perhaps?) and many frustrating battles to get that 
issue rectified, and the result was that sole '$' token

> 
> Will use of "$" be faster than using a local reference?
> 
> Unless there is a reason not to create a local reference to an array, I 
> don't think either "length" or "$" are necessary. At least "$" shouldn't 
> cause programming errors, but it does make the language more complex.

It was argued at the time that $len should be used, so that the $ prefix 
could thus signify meta-notions in general ($file, $line, $time, etc). 
In fact, it was perhaps the only time I recall a general concensus on 
anything ;)

But, that notion went nowhere as you can see. We just move on