Re:Show HN: Eole, a Lévy-optimal lambda calculus evaluator w...
by HerrmannM on Monday October 21, 2019 @08:33AM
(#21311512)
I'm glad you find interest in this work.
Thank you for the links, I did not know we could do computation with... chemistry! As I'm not familiar with that, I do not understand everything. Can you point me to a list of the interactions of your system?
Formality indeed looks promising. I still have a lot to learn about EAL in order to forge my opinion, but maybe it is the "sweet spot". For example, Formality does not need a GC, whereas Éole does, which is time consuming. On the other hand, Éole (if it works) is completely general. But then, not being "completely general" isn't necessary a problem, and Formality seems to do very well.
Please note that Éole is not proven yet, and I'm looking for counter examples that might settle the case. I will actually be happy if someone "break" the system!
Re:Show HN: Eole, a Lévy-optimal lambda calculus evaluator w...
by xorand on Monday October 21, 2019 @10:49AM
(#21312883)
EDIT: Re: the chemistry, I do think that it might be a big subject, see https://arxiv.org/abs/1811.04960 , which somehow is not very surprising because of the Algorithmic Chemistry (aka ALCHEMY) of Fontana and Buss.
Re:Show HN: Eole, a Lévy-optimal lambda calculus evaluator w...
by danharaj on Monday October 21, 2019 @08:43AM
(#21311588)
Did you demonstrate that your trick is sound and optimal? Optimal reduction is a tricky beast and you might need to use a very high order function to find a counterexample.
Re:Show HN: Eole, a Lévy-optimal lambda calculus evaluator w...
by HerrmannM on Monday October 21, 2019 @07:19PM
(#21318665)
A tricky beast indeed!
No, the formal proof is a work in progress, so I'm also looking for counter-examples. And since posting on hackernews, someone found some problems (thank you so much Ekdohibs). However, there is for sure an implementation issue so they do not count as counter-examples yet. I'll investigate and fix that asap, then we'll see...
Re:Show HN: Eole, a Lévy-optimal lambda calculus evaluator w...
by HerrmannM on Monday October 21, 2019 @07:25PM
(#21318701)
Of course not, monads are so 20th century... The October 2019 way is to only work with stacks of TripleZippersInvertedStateTransformerLens, and I know you know it!
Re:Show HN: Eole, a Lévy-optimal lambda calculus evaluator w...
by HerrmannM on Monday October 21, 2019 @10:06PM
(#21319712)
Joke aside, it is supposed (I have some interesting bugs at the moment) to be an evaluator for the pure lambda calculus. So, I guess you can encode monads in it, but that is not really the point, and I definitely did not make an example with monads. I'll try to do such an example later.
[0] https://github.com/moonad/Formality
[1] http://imar.ro/~mbuliga/chemlambda-v2.html
[2] https://www.reddit.com/r/haskell/comments/dih8xu/optimal_red...
[3] https://mbuliga.github.io/kali24.html
Thank you for the links, I did not know we could do computation with... chemistry! As I'm not familiar with that, I do not understand everything. Can you point me to a list of the interactions of your system?
Formality indeed looks promising. I still have a lot to learn about EAL in order to forge my opinion, but maybe it is the "sweet spot". For example, Formality does not need a GC, whereas Éole does, which is time consuming. On the other hand, Éole (if it works) is completely general. But then, not being "completely general" isn't necessary a problem, and Formality seems to do very well.
Please note that Éole is not proven yet, and I'm looking for counter examples that might settle the case. I will actually be happy if someone "break" the system!