faster splitter

[Chris via Digitalmars-d]

On Monday, 23 May 2016 at 22:19:18 UTC, Andrei Alexandrescu wrote:
> On 05/23/2016 03:11 PM, qznc wrote:
>
> Conventional wisdom has it that find() is brute force and 
> that's that, but probably it's time to destroy. Selectively 
> using advanced searching algorithms for the appropriate inputs 
> is very DbI-ish.
>
> There are a few nice precedents of blend algorithms, see e.g. 
> http://effbot.org/zone/stringlib.htm.
>
> Writing a generic subsequence search blend algorithm, one that 
> chooses the right algorithm based on a combination of static 
> and dynamic decisions, is quite a fun and challenging project. 
> Who wanna?
>
>
> Andrei

I've played around with some algorithms and kept them as simple 
as possible, but I've found that a linear brute force for-loop 
always beats them (it's the extra decision(s), I suppose). It 
looks nice in theory, but in hardware reality a stupid loop is 
more efficient.

NB: I've found that `foreach` is usually faster than a manual 
`for`-loop.

I used qznc's benchmarking, and it's clear that the current 
implementation of std.algorithm.find is quite a poor performer. 
We do have to work on that. Library functions should be fast, no 
matter what. If someone uses `find`, they wanna be sure it's 
optimized for speed.