On 15 April 2013 22:08, Daniel Llorens <daniel.llor...@bluewin.ch> wrote: > > On Apr 15, 2013, at 14:28, Daniel Hartwig wrote: > >> Is it >> really much faster to do one or the other: >> >> if lbnd != 0: error >> index = … >> >> vs: >> >> index = lbnd + ... > > The second should actually be just > > index = ... > > You do this by having the base index point to the element at index 0 > and not to the first element. This is a mistake all through the Guile > array code.
So lbnd is only for range checking. Neat. > > A branch would certainly be slower. However, if the array implementation > was exposed to the compiler, the lbnd!=0 check could be hoisted out of > any array loop. So both would end up being identical in that case. I see.
