tag:blogger.com,1999:blog-9101292118679422945.post4768917548653396328..comments2023-05-06T23:39:44.223+09:00Comments on Conrad Parker: A monoid for server partiesAnonymoushttp://www.blogger.com/profile/15413914110610213900noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-9101292118679422945.post-55461815999398119392010-06-08T18:00:16.978+09:002010-06-08T18:00:16.978+09:00Also there is another example: a Unix program dete...Also there is another example: a Unix program determines a value for some configuration parameter in this order: "CLI parameter", "~/…", "/etc/…", "default value". Not specified = mempty.<br />"parameter value" = "CLI parameter" `mappend` "~/…" `mappend` "/etc/…" `mappend` "default value"beroalhttps://www.blogger.com/profile/13229768366613602827noreply@blogger.comtag:blogger.com,1999:blog-9101292118679422945.post-21420422828108786432010-06-08T17:28:56.318+09:002010-06-08T17:28:56.318+09:00SQL NULL is more like bottom than mempty
In genera...<em>SQL NULL is more like bottom than mempty</em><br />In general — maybe, here I am talking about COALESCE only.beroalhttps://www.blogger.com/profile/13229768366613602827noreply@blogger.comtag:blogger.com,1999:blog-9101292118679422945.post-5241646045271662502010-06-08T08:02:45.462+09:002010-06-08T08:02:45.462+09:00beroal: I would have thought SQL NULL is more like...beroal: I would have thought SQL NULL is more like bottom than mempty?Anonymoushttps://www.blogger.com/profile/15413914110610213900noreply@blogger.comtag:blogger.com,1999:blog-9101292118679422945.post-24763534011958161432010-06-07T19:46:35.063+09:002010-06-07T19:46:35.063+09:00Conrad, do you know a standard name for that stran...Conrad, do you know a standard name for that strange monoid?<br />∀ f g. f ≠ mempty → f `mappend` g = f<br />sigfpe is silent on this issue. The monoid is similar to COALESCE in SQL, where NULL=mempty.beroalhttps://www.blogger.com/profile/13229768366613602827noreply@blogger.comtag:blogger.com,1999:blog-9101292118679422945.post-3543772979424152312010-05-09T03:39:19.472+09:002010-05-09T03:39:19.472+09:00I found this tutorial pretty much awesome.
(Not c...I found this tutorial pretty much awesome.<br /><br />(Not convinced that Happstack is so obviously a bit deeper than the average Web framework, though.)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-9101292118679422945.post-14367950153429529332010-05-08T17:11:34.349+09:002010-05-08T17:11:34.349+09:00I found the tutorial pretty much entirely incompre...I found the tutorial pretty much entirely incomprehensible. I'd like something that starts off by showing me some simple but useful code to maybe display a form, handle a POST and display a result. Some kind of idea of whether it's worth learning all the rest of the stuff.<br /><br />Actually, documentation quality is a sore point with every Haskell webby thing I've ever tried. I'Possible Piperhttps://www.blogger.com/profile/11658364568703042795noreply@blogger.com