[Haskell-cafe] Language semantics

[Neil Mitchell]

Hi

> > What's Uniplate?
>
> http://www-users.cs.york.ac.uk/~ndm/uniplate/ may help to answer that
> question. I haven't even finished understanding SYB, yet, though; I'm
> still mystified by how to use Data.Generics.Twins.gzipWithQ. So, I'm
> not at a stage where I can usefully contrast Uniplate with the
> Data.Generics stuff.

Uniplate should be easier to understand than SYB. The draft paper on
that web page compares Uniplate to SYB (and Compos). It also has
plenty of examples of how to use Uniplate to do tasks. The manual on
that page has suggested exercises to check that you can understand and
extend Uniplate code.

Uniplate produces more concise code, has traversal operations that are
not present in the SYB library, runs faster and works in Hugs. SYB is
capable of many more generic operations than Uniplate, such as
gzipWithQ and much much more.

Thanks

Neil