Re: substitution in a list

[Luca Saiu]

Ian Grant wrote:
> It would be a good idea to do it this way if the list of substitutions
> were much longer than the list where they are being made. But if the
> substitution list is short then looking up a symbol is relatively cheap
> compared to consing up the transformed list and reversing it, so it
> would be better to test each symbol once.

An asymptotically optimal solution would be making a hash from the 
alist, and iterating on the (reversed) list just once, as you do; I 
guess I'd go for it in a practical case.

I was just trying to be didactic. :-)

--
Luca Saiu, maintainer of GNU epsilon
http://www.gnu.org/software/epsilon
http://www.di.unipi.it/~saiu