Re: Scheme style auto-resizing hashtable (fwd)

[hjstein@bfr.co.il (Harvey J. Stein)]

Chris.Bitmead@misys.com.au writes:

 > >In any case, Henry Baker has a nice paper about how mapping is where
 > >it's at & how iterators are just a weak add-in to a broken language.
 > 
 > Can I download this paper from somewhere?
 > 
 > I was going to disagree, but then I thought I should read the arguments
 > first.

Ok.  I found it for you:

   Iterators: Signs of Weakness in Object-Oriented Languages
   ftp://ftp.netcom.com/pub/hb/hbaker/Iterator.html
   ftp://ftp.netcom.com/pub/hb/hbaker/Iterator.ps.Z

Here's the abstract:

   The appearance of iterators in an object-oriented language appears
   to be inversely related to the power of the language's intrinsic
   control structures. Iterator classes are used for the sole purpose
   of enumerating the elements of an abstract collection class without
   revealing its implementation. We find that the availability of
   higher-order functions and function closures eliminates the need
   for these ad hoc iterator classes, in addition to providing the
   other benefits of "mostly functional programming". We examine a
   purely functional iteration protocol for the difficult task of
   comparing the collections of leaves on two non-isomorphic
   trees--the so-called "samefringe" problem--and find that its type
   signature requires recursive (cyclic) functional types.  Although
   higher-order "member functions" and recursive (cyclic) functional
   types are unusual in object-oriented languages, they arise quite
   naturally and provide a satisfying programming style.

-- 
Harvey J. Stein
BFM Financial Research
hjstein@bfr.co.il