Comments on: And is this Haskell? http://www.e-pig.org/epilogue/?p=198 for Epigram Sun, 6 Nov 2011 09:25:45 +0000 http://wordpress.org/?v=2.8.4 hourly 1 By: Conor http://www.e-pig.org/epilogue/?p=198&cpage=1#comment-70781 Conor Fri, 03 Jul 2009 07:27:07 +0000 http://www.e-pig.org/epilogue/?p=198#comment-70781 I haven't written that piece yet. So far, it's partly a feasibility study and partly about tooling up for Epigram hacking. I've been working with SPJ and Dimitris Vytiniotis on doing the {..} stuff for real: this is just a mockup to let people try out examples. Pattern synonyms are there to support "datatype coding" in general. If you code your data as fixpoints of sums of products, you get lots of generic goodies cheap but your type-specific functions look ugly as sin: pattern synonyms get you back where you were. You can see what happens if you put the two ideas together <a href="http://strictlypositive.org/slicing-jpgs/" rel="nofollow">here</a>. In a similar vein, the Epigram implementation is quite <a href="http://www.e-pig.org/epilogue/?p=143" rel="nofollow">reflective</a>, so we need to write Haskell programs manipulating Epigram data structures. Pattern synonyms let us write Nil instead of Pair [Z [], Void []] or whatever it turns out to be. More code will survive the inevitable changes of internal representation. To sum up, there's no grand plan: it's a bunch of loosely related experiments and some kit whose absence we've felt in the past. I haven’t written that piece yet. So far, it’s partly a feasibility study and partly about tooling up for Epigram hacking. I’ve been working with SPJ and Dimitris Vytiniotis on doing the {..} stuff for real: this is just a mockup to let people try out examples. Pattern synonyms are there to support “datatype coding” in general. If you code your data as fixpoints of sums of products, you get lots of generic goodies cheap but your type-specific functions look ugly as sin: pattern synonyms get you back where you were. You can see what happens if you put the two ideas together here.

In a similar vein, the Epigram implementation is quite reflective, so we need to write Haskell programs manipulating Epigram data structures. Pattern synonyms let us write Nil instead of Pair [Z [], Void []] or whatever it turns out to be. More code will survive the inevitable changes of internal representation.

To sum up, there’s no grand plan: it’s a bunch of loosely related experiments and some kit whose absence we’ve felt in the past.

]]> By: Daniel http://www.e-pig.org/epilogue/?p=198&cpage=1#comment-70780 Daniel Thu, 02 Jul 2009 18:11:54 +0000 http://www.e-pig.org/epilogue/?p=198#comment-70780 This (and the previous blog entry) looks exciting! Do you have an overview somewhere of what your end goal is here? This (and the previous blog entry) looks exciting! Do you have an overview somewhere of what your end goal is here?

]]> By: Conor http://www.e-pig.org/epilogue/?p=198&cpage=1#comment-70778 Conor Wed, 01 Jul 2009 16:30:28 +0000 http://www.e-pig.org/epilogue/?p=198#comment-70778 I'm keen to help that to happen. I’m keen to help that to happen.

]]> By: Pepe Iborra http://www.e-pig.org/epilogue/?p=198&cpage=1#comment-70775 Pepe Iborra Wed, 01 Jul 2009 12:41:51 +0000 http://www.e-pig.org/epilogue/?p=198#comment-70775 Can we have this in he (the manly GHC of course) please ? Can we have this in he (the manly GHC of course) please ?

]]> By: Conor http://www.e-pig.org/epilogue/?p=198&cpage=1#comment-70773 Conor Wed, 01 Jul 2009 08:23:51 +0000 http://www.e-pig.org/epilogue/?p=198#comment-70773 I just added an example file with treeSort, mostly to test that pattern synonyms are propagated along with module imports (via the mysterious and entirely readable .hers file that she creates). A few more bits and pieces (idiom brackets that work, some vaguely aspecty gadgets) and we're set for a summer of hacking. I'm quite sure she's full of quirks and infelicities just now, and slow to boot, but things will improve as and when they need to. I just added an example file with treeSort, mostly to test that pattern synonyms are propagated along with module imports (via the mysterious and entirely readable .hers file that she creates). A few more bits and pieces (idiom brackets that work, some vaguely aspecty gadgets) and we’re set for a summer of hacking. I’m quite sure she’s full of quirks and infelicities just now, and slow to boot, but things will improve as and when they need to.

]]> By: Pepe Iborra http://www.e-pig.org/epilogue/?p=198&cpage=1#comment-70772 Pepe Iborra Wed, 01 Jul 2009 07:14:09 +0000 http://www.e-pig.org/epilogue/?p=198#comment-70772 Yay ! Yay !

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