good, it felt like something that might have occurred to someone before.
On 1/23/07, Nicolas Frisby <[EMAIL PROTECTED]> wrote:
Jeremy Gibbons thought of it; that's good company ;) http://portal.acm.org/citation.cfm?id=289457 On 1/23/07, Steve Downey <[EMAIL PROTECTED]> wrote: > (overall context - working through TaPL on my own, reimplemnting > typecheckers in haskell) > the type checkers all follow the same pattern, in ocaml they throw an > exception when the small step fails, which may mean taking another > branch in the eval, but that that sub expression has hit bottom. > > it is self admittedly not good ocaml, and it seems to be even worse > haskell, as i try to extend the simple evaluator i have to deal with > managing reporting errors. > > having the single small step evaluator return a Maybe is fairly close. > then the evaluator above it just bottoms out when eval1 expr returns > Nothing, by passing expr back up as the result. > > but it occurs to me that it might be better to express it as an > unfold, where the result is a list with the last element as the > irresucible expression. > > or am i insane / intoxicated ? > _______________________________________________ > Haskell-Cafe mailing list > [email protected] > http://www.haskell.org/mailman/listinfo/haskell-cafe >
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