Comments on: Elegant memoization with functional memo tries http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries Inspirations & experiments, mainly about denotative/functional programming in Haskell Sat, 18 May 2013 00:33:37 +0000 hourly 1 http://wordpress.org/?v=3.1 By: Audun http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries/comment-page-1#comment-113441 Audun Tue, 29 May 2012 11:12:47 +0000 http://conal.net/blog/?p=54#comment-113441 <p>Thank you for adding the instance, and for the attribution :)</p> <p>If you make another release, you can add my full name: Audun Skaugen (no hurry, though).</p> <p>Oh, and sorry for the code formatting in the previous comment; that's what you get for not previewing.</p> Thank you for adding the instance, and for the attribution :)

If you make another release, you can add my full name: Audun Skaugen (no hurry, though).

Oh, and sorry for the code formatting in the previous comment; that’s what you get for not previewing.

]]> By: conal http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries/comment-page-1#comment-109124 conal Sun, 06 May 2012 23:12:04 +0000 http://conal.net/blog/?p=54#comment-109124 <p>Hi Audun. I like your idea of a <code>HasTrie Void</code> instance. Omitting it was an oversight. I just added your instance and released <a href="http://hackage.haskell.org/package/MemoTrie-0.4.12" rel="nofollow">version 0.4.12</a>.</p> <p>I think you meant "there is one function <code>Void -> a</code>" (rather than none), ignoring bottoms, namely the empty function.</p> Hi Audun. I like your idea of a HasTrie Void instance. Omitting it was an oversight. I just added your instance and released version 0.4.12.

I think you meant “there is one function Void -> a” (rather than none), ignoring bottoms, namely the empty function.

]]> By: Audun http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries/comment-page-1#comment-107190 Audun Sat, 21 Apr 2012 19:26:45 +0000 http://conal.net/blog/?p=54#comment-107190 <p>Hi, I had use for a HasTrie instance for the Void type. I could think of two instances. The instance that would seem to follow from the isomorphisms is:</p> <p>instance HasTrie Void where data Void :->: a = VoidTrie trie _ = VoidTrie untrie VoidTrie = absurd enumerate VoidTrie = []</p> <p>That is, there are no functions Void -> a, and a^Void is isomorphic to Unit. However, this instance makes constant functions strict, so that memo (const a) undefined == undefined. This can be alleviated with an instance closer to the Unit instance.</p> <p>Any thoughts? Would you be willing to add a Void instance to MemoTrie?</p> Hi, I had use for a HasTrie instance for the Void type. I could think of two instances. The instance that would seem to follow from the isomorphisms is:

instance HasTrie Void where data Void :->: a = VoidTrie trie _ = VoidTrie untrie VoidTrie = absurd enumerate VoidTrie = []

That is, there are no functions Void -> a, and a^Void is isomorphic to Unit. However, this instance makes constant functions strict, so that memo (const a) undefined == undefined. This can be alleviated with an instance closer to the Unit instance.

Any thoughts? Would you be willing to add a Void instance to MemoTrie?

]]> By: Conal Elliott » Blog Archive » Memoizing polymorphic functions via unmemoization http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries/comment-page-1#comment-59067 Conal Elliott » Blog Archive » Memoizing polymorphic functions via unmemoization Sat, 02 Oct 2010 15:40:49 +0000 http://conal.net/blog/?p=54#comment-59067 <p>[...] can work out an answer by appealing to the same laws of exponents used in memoization, but now applied in reverse (to create function types instead of eliminate [...]</p> [...] can work out an answer by appealing to the same laws of exponents used in memoization, but now applied in reverse (to create function types instead of eliminate [...]

]]> By: Conal Elliott » Blog Archive » Memoizing higher-order functions http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries/comment-page-1#comment-50257 Conal Elliott » Blog Archive » Memoizing higher-order functions Wed, 21 Jul 2010 15:41:24 +0000 http://conal.net/blog/?p=54#comment-50257 <p>[...] all at once from a denotational perspective, and incrementally from an operational perspective. See Elegant memoization with functional memo tries and Elegant memoization with higher-order [...]</p> [...] all at once from a denotational perspective, and incrementally from an operational perspective. See Elegant memoization with functional memo tries and Elegant memoization with higher-order [...]

]]> By: Conal Elliott » Blog Archive » Elegant memoization with higher-order types http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries/comment-page-1#comment-50187 Conal Elliott » Blog Archive » Elegant memoization with higher-order types Wed, 21 Jul 2010 04:48:29 +0000 http://conal.net/blog/?p=54#comment-50187 <p>[...] using the essential idea of Ralf Hinze’s paper Generalizing Generalized Tries. The blog post Elegant memoization with functional memo tries describes a library, MemoTrie, based on both of these sources, and using associated data types. I [...]</p> [...] using the essential idea of Ralf Hinze’s paper Generalizing Generalized Tries. The blog post Elegant memoization with functional memo tries describes a library, MemoTrie, based on both of these sources, and using associated data types. I [...]

]]> By: Conal Elliott » Blog Archive » Nonstrict memoization http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries/comment-page-1#comment-49242 Conal Elliott » Blog Archive » Nonstrict memoization Wed, 14 Jul 2010 02:46:28 +0000 http://conal.net/blog/?p=54#comment-49242 <p>[...] written a few posts about functional memoization. In one of them, Luke Palmer commented that the memoization methods are correct only for strict functions, which I [...]</p> [...] written a few posts about functional memoization. In one of them, Luke Palmer commented that the memoization methods are correct only for strict functions, which I [...]

]]> By: Conal Elliott » Blog Archive » Memoizing polymorphic functions - part two http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries/comment-page-1#comment-32215 Conal Elliott » Blog Archive » Memoizing polymorphic functions - part two Fri, 20 Nov 2009 19:33:26 +0000 http://conal.net/blog/?p=54#comment-32215 <p>[...] Comments conal on Elegant memoization with functional memo triesShawn Willden on Elegant memoization with functional memo triesDave Crossland on Seeking advice on [...]</p> [...] Comments conal on Elegant memoization with functional memo triesShawn Willden on Elegant memoization with functional memo triesDave Crossland on Seeking advice on [...]

]]> By: conal http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries/comment-page-1#comment-31832 conal Sat, 14 Nov 2009 19:22:02 +0000 http://conal.net/blog/?p=54#comment-31832 <p>@Shawn -- Fixed now. Thanks for the note.</p> @Shawn — Fixed now. Thanks for the note.

]]> By: Shawn Willden http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries/comment-page-1#comment-31813 Shawn Willden Sat, 14 Nov 2009 07:13:13 +0000 http://conal.net/blog/?p=54#comment-31813 <p>Your source code links are broken. Could you please fix them so I can understand what it is you're talking about? Thanks.</p> Your source code links are broken. Could you please fix them so I can understand what it is you’re talking about? Thanks.

]]> By: Conal Elliott » Blog Archive » Memoizing polymorphic functions - part one http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries/comment-page-1#comment-22207 Conal Elliott » Blog Archive » Memoizing polymorphic functions - part one Thu, 11 Jun 2009 00:36:40 +0000 http://conal.net/blog/?p=54#comment-22207 <p>[...] reuses rather than recomputes when applied to the same argument more than once. Variations include not-quite-equivalence due to added strictness, and replacing value equality with pointer [...]</p> [...] reuses rather than recomputes when applied to the same argument more than once. Variations include not-quite-equivalence due to added strictness, and replacing value equality with pointer [...]

]]> By: Conal Elliott » Blog Archive » Simpler, more efficient, functional linear maps http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries/comment-page-1#comment-11163 Conal Elliott » Blog Archive » Simpler, more efficient, functional linear maps Sun, 09 Nov 2008 22:16:12 +0000 http://conal.net/blog/?p=54#comment-11163 <p>[...] However, there are several other ways to make linear maps, and it would be easy to forget to memoize each combining form. So, instead of the function representation above, I ensure that the function be memoized by representing it as a memo trie. [...]</p> [...] However, there are several other ways to make linear maps, and it would be easy to forget to memoize each combining form. So, instead of the function representation above, I ensure that the function be memoized by representing it as a memo trie. [...]

]]> By: Conal Elliott » Blog Archive » Vector space bases via type families http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries/comment-page-1#comment-10304 Conal Elliott » Blog Archive » Vector space bases via type families Mon, 20 Oct 2008 01:23:36 +0000 http://conal.net/blog/?p=54#comment-10304 <p>[...] rules are also essentially the same as the ones used for memo tries, but phrased in terms of logarithms instead of (explicit) exponents. Tags: type families, vector [...]</p> [...] rules are also essentially the same as the ones used for memo tries, but phrased in terms of logarithms instead of (explicit) exponents. Tags: type families, vector [...]

]]> By: conal http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries/comment-page-1#comment-10190 conal Thu, 16 Oct 2008 23:52:47 +0000 http://conal.net/blog/?p=54#comment-10190 <p>I said to <a href="http://luqui.org/blog" rel="nofollow">Luke</a></p> <blockquote> I'd love to read a blog post about your library, especially where you exploit the flexibility of explicit memoizers. </blockquote> <p>Oh! Now I see that you <a href="http://luqui.org/blog/archives/2008/10/14/data-memocombinators/" rel="nofollow">have written</a>. I'd still like to see some nice examples if you get around to it.</p> I said to Luke

I’d love to read a blog post about your library, especially where you exploit the flexibility of explicit memoizers.

Oh! Now I see that you have written. I’d still like to see some nice examples if you get around to it.

]]> By: Dave Menendez http://conal.net/blog/posts/elegant-memoization-with-functional-memo-tries/comment-page-1#comment-10187 Dave Menendez Thu, 16 Oct 2008 21:27:21 +0000 http://conal.net/blog/?p=54#comment-10187 <blockquote> <p>Any thoughts on this dilemma?</p> </blockquote> <p>Well, there's not much point memoizing a constant function. Also, a strict instance for () is more consistent with the other instances.</p>

Any thoughts on this dilemma?

Well, there’s not much point memoizing a constant function. Also, a strict instance for () is more consistent with the other instances.

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