[Ecls-list] More about NIL

[Juan Jose Garcia-Ripoll]

Along the same branch, ECL now has the feature mentioned long ago,
which is that conses are represented by two words and no type tag: the
type is detected by the least significant bit of the pointer.
Currently this does not represent a big improvement over the times
shown before because:

1) The routines dealing with lists have not been yet optimized to use
LISTP() instead of CONSP() and other simplifications.

2) I have not yet discovered how to allocate less than 16 bits per
object using the Boehm-Weiser garbage collector. This means in
practice TIME reports the same about of bytes consed for any routine
using lists.

Juanjo

-- 
Facultad de Fisicas, Universidad Complutense,
Ciudad Universitaria s/n Madrid 28040 (Spain)
http://juanjose.garciaripoll.googlepages.com