Speed kills

[ixid via Digitalmars-d]

Every time there is a D thread on reddit it feels like the new 
user is expecting mind-blowing speed from D.

https://www.reddit.com/r/programming/comments/45v03g/porterstemmerd_an_implementation_of_the_porter/

This is the most recent one where John Colvin provided some 
pointers to speed it up significantly. Walter has done some good 
work taking the low-hanging fruit to speed up DMD code and there 
is a lot of effort going on with reference counting machinery but 
I wondered if some of the common errors people make that slow 
down D code can be addressed?

Literals used to be a hidden speed bump but I think that was 
improved, now the append operator is one of the most common 
culprits, can this not be enhanced behind the scenes to work more 
like append? Do others notice common pitfalls between the article 
code and what the D community then suggests where we can bridge 
the gap so naive users get faster code?