From: jim Date: Thu, 19 Mar 2015 18:22:20 +0000 (-0400) Subject: formatting X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=commitdiff_plain;h=2560da9245de9d85d19d4513fd3ac6100c8c4225 formatting --- diff --git a/topics/week7_introducing_monads.mdwn b/topics/week7_introducing_monads.mdwn index 33bdc979..7dbb55fc 100644 --- a/topics/week7_introducing_monads.mdwn +++ b/topics/week7_introducing_monads.mdwn @@ -14,13 +14,6 @@ sometimes sloganized as [A monad is just a monoid in the category of endofunctors, what's the problem?](http://stackoverflow.com/questions/3870088). Without some intuitive guidance, this can also be unhelpful. We'll try to find a good balance. -(After you've read this once and are coming back to re-read it to try to digest the details further, the "endofunctors" that slogan is talking about are the boxing operations. Their "monoidal" character is captured in the Monad Laws, where a "monoid"---don't confuse with a mon*ad*---is a simpler algebraic notion, meaning a universe with some associative operation that has an identity. For advanced study, here are some further links on the relation between monads as we're working with them and monads as they appear in category theory: -[1](http://en.wikipedia.org/wiki/Outline_of_category_theory) -[2](http://lambda1.jimpryor.net/advanced_topics/monads_in_category_theory/) -[3](http://en.wikibooks.org/wiki/Haskell/Category_theory) -[4](https://wiki.haskell.org/Category_theory), where you should follow the further links discussing Functors, Natural Transformations, and Monads.) - - The closest we will come to metaphorical talk is to suggest that monadic types place values inside of *boxes*, and that monads wrap @@ -29,6 +22,13 @@ any case, our emphasis will be on starting with the abstract structure of monads, followed by instances of monads from the philosophical and linguistics literature. +> After you've read this once and are coming back to re-read it to try to digest the details further, the "endofunctors" that slogan is talking about are the boxing operations. Their "monoidal" character is captured in the Monad Laws, where a "monoid"---don't confuse with a mon*ad*---is a simpler algebraic notion, meaning a universe with some associative operation that has an identity. For advanced study, here are some further links on the relation between monads as we're working with them and monads as they appear in category theory: +[1](http://en.wikipedia.org/wiki/Outline_of_category_theory) +[2](http://lambda1.jimpryor.net/advanced_topics/monads_in_category_theory/) +[3](http://en.wikibooks.org/wiki/Haskell/Category_theory) +[4](https://wiki.haskell.org/Category_theory), where you should follow the further links discussing Functors, Natural Transformations, and Monads. + + ## Box types: type expressions with one free type variable ## Recall that we've been using lower-case Greek letters