[Haskell-cafe] Prolog-style patterns

[Johannes Waldmann]

Yuras Shumovich <shumovichy <at> gmail.com> writes:

> Will not it be a nightmare to implement and maintain checker for
> overlapping/unused clauses for non-linear patterns?

For sure it does not look straightforward. 

Note that there are some results and algorithms 
for non-linear patterns, cf. this short survey by S. Tison: 
"Tree Automata, (Dis-)Equality Constraints and Term Rewriting: What's New?"
http://drops.dagstuhl.de/opus/frontdoor.php?source_opus=3140
and some background in "Tree automata with constraints" 
(esp. Sec. 4.4.5) http://tata.gforge.inria.fr/chap4.php

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(overlap checking for) non-linear patterns in Haskell
looks like an ideal topic  for a submission to the 
"Haskell and Rewriting" workshop http://www.imn.htwk-leipzig.de/HART2013/