faster splitter

[qznc via Digitalmars-d]

On Tuesday, 31 May 2016 at 01:55:16 UTC, Andrei Alexandrescu 
wrote:
> I agree it's difficult to characterize the behavior of 
> substring search with one number. There are many dimensions of 
> variation. (But there's no reason for an emotional response.) A 
> few possible baselines come to mind:
>
> * Search a long string for a one-character string, match and 
> fail.

There is a special version of find for searching a single char in 
a string. Using a one-letter needle string is more like a user 
mistake than something to optimize for.

> * Take an English text string. Search for a substring 
> consisting of its last portion (e.g. 5% of the length).

How long should the english text be? A Tweet? A book? A Gigabyte 
of log files?

English text means basically ASCII and no Unicode?

> * Take an English text string. Search for a substring 
> consisting of a fraction of the text (e.g. 3%) with additional 
> characters prepended. Repeat for appended.

Why the prepend/append? To force a mismatch?