!in

[Andrei Alexandrescu]

bearophile wrote:
> Andrei Alexandrescu:
> 
>> Generally I'd be hesitant to make it all too easy to do linear
>> searches. Too much of that would encourage people to stick with
>> linear searches because it's the path of least resistance.<
> 
> D programmers know the difference between linear search, hash search
> and search in an ordered search tree. They are O(n), O(1), and O(ln
> n). Do you want to use a different name for each of those searches
> (and maybe a (n log log n if you search with interpolated search,
> etc) just because their computational complexity is different, or do
> you want just a syntax that asks the collection to find something
> using the faster code it has?

I think you're giving D programmers too much credit. I think a 
best-effort search is not widely useful.

>> Searching a value in a literal should actually be allowed: x in
>> [10, 20, 30, 0]<
> 
> This is very wrong. No special cases, please. If you don't want to
> support the linear search on all arrays, then please don't add this
> feature at all, I will keep using my isIn templated function (that
> digests AAs too, lazy iterables, etc too of course). I don't want
> more warts and special cases in D, thank you. As Python Zen says:
> "Special cases aren't special enough to break the rules." Such rules
> must be read and understood by D devs too, if you want to make a
> language that's not a mess as C++.

Searching an array literal vs. an array variable is not a special case.

Andrei