X-Git-Url: http://lambda.jimpryor.net/git/gitweb.cgi?p=lambda.git;a=blobdiff_plain;f=hints%2Fassignment_7_hint_3.mdwn;h=0629c1ba426040725da39cea1370e20a212bc69b;hp=838a2af06c771c5a9a027ec884738cca9ba84aa0;hb=66ef1a36f8860c2fbccc353eded363c8a2040a04;hpb=a63e962a82f5136828fa6688a12d259cb09c5a4e diff --git a/hints/assignment_7_hint_3.mdwn b/hints/assignment_7_hint_3.mdwn index 838a2af0..0629c1ba 100644 --- a/hints/assignment_7_hint_3.mdwn +++ b/hints/assignment_7_hint_3.mdwn @@ -7,11 +7,11 @@ We're going to keep all of that, except dropping the worlds. And instead of talking about -> \[[expression]] in discourse possibility `(r, g, w)` +> \[[expression]] in possibility `(r, g, w)` we'll just talk about \[[expression]] and let that be a monadic object, implemented in part by a function that takes `(r, g)` as an argument. -More specifically, \[[expression]] will be a set of 'a discourse possibility monads, where 'a is the appropriate type for "expression," and the discourse possibility monads are themselves state monads where `(r, g)` is the state that gets updated. Those are implemented as functions from `(r, g)` to `(a, r', g')`, where `a` is a value of type `'a`, and `r', g'` are possibly altered assignment functions and stores. +More specifically, \[[expression]] will be a set of `'a discourse possibility` monads, where `'a` is the appropriate type for *expression*, and the discourse possibility monads are themselves state monads where `(r, g)` is the state that gets updated. Those are implemented as functions from `(r, g)` to `(a, r', g')`, where `a` is a value of type `'a`, and `r', g'` are possibly altered assignment functions and stores. * In def 2.7, GS&V talk about an operation that takes an existing set of discourse possibilities, and extends each member in the set by allocating a new location in the store, and assigning a variable `'x'` to that location, which holds some object `d` from the domain. It will be useful to have a shorthand way of referring to this operation: