Thomas Bushnell BSG scripsit:

> The Lisp way, much more preferable, is that [declarations] are mere suggestions,
> which *must not* affect the performance of correct code.

I assume you mean "must not affect the behavior, but may affect the
performance" (= speed).  Unfortunately, you have to be intimately
familiar with your CL implementation to know when declarations are
useless, when they are critical to performance, and when they actually
make things worse.

"Lisp programmers know the value of everything and the cost of nothing."

--
It was dreary and wearisome.  Cold clammy winter still held way in this
forsaken country.  The only green was the scum of livid weed on the dark
greasy surfaces of the sullen waters.  Dead grasses and rotting reeds loomed
up in the mists like ragged shadows of long-forgotten summers.
        --"The Passage of the Marshes"          http://www.ccil.org/~cowan