Ahh... I get it now! Thanks for your patience :) I have a new question: I'm working on supporting literals now. I'm having trouble creating something that looks like `(App (Var F#) (Lit 1.0))` because I don't know how to create a variable that corresponds to the `F#` constructor. The mkWiredInName function looks promising, but overly complicated. Is this the correct function? If so, what do I pass in for the Module, Unique, TyThing, and BuiltInSyntax parameters?
On Thu, Aug 20, 2015 at 5:55 PM, Andrew Farmer <afar...@ittc.ku.edu> wrote: > The `buildDictionary` function takes a Var with a dictionary type, and > builds the expression which implements that dictionary. > > For instance, you might create a new Var: > > x :: Num Float > > and pass that to buildDictionary. It will return: > > (x, [NonRec x $fNumFloat]) > > which you could blindly turn into: > > let x = $fNumFloat > in x > > or you could do what buildDictionaryT (a bit further down in the same > module), and spot that case and just return $fNumFloat directly. (The > list can have more than one element in the case that dictionaries are > built in terms of other dictionaries.) > > Thus, you've built a dictionary expression of type Num Float. > > As I understand it, you want to pass something 'log' and get back the > dictionary argument. You'll need to choose a type (like Float), but > once that is done, it should be easy to use buildDictionary to build > the dictionary arguments... just take apart the type of 'log @ Float', > make a new Var with the argument type, build a dictionary expression, > and apply it. > > On Thu, Aug 20, 2015 at 5:05 PM, Mike Izbicki <m...@izbicki.me> wrote: >> I'm pretty sure the `buildDictionary` function doesn't do what I need. >> AFAICT, you pass it a `Var` which contains a dictionary, and it tells >> you what is in that dictionary. What I need is a function with type >> `Var -> Var` where the first `Var` contains a function, and the output >> `Var` is the dictionary. >> >> For example, given the expression: >> >> log (a1+a2) >> >> In core, this might look like: >> >> log @ Float $fFloatingFloat (+ @ Float $fNumFloat a1 a2) >> >> I want to mechanically construct the core code above. When doing so, >> each function within a type class has an extra argument, which is the >> dictionary for that type class. `log` no longer takes one parameter; >> in core, it takes two. I'm having trouble figuring out how to get the >> appropriate dictionary to pass as the "dictionary parameter" to these >> functions. >> >> On Mon, Aug 17, 2015 at 4:21 PM, Andrew Farmer <afar...@ittc.ku.edu> wrote: >>> HERMIT has some code for building dictionaries for a given predicate >>> type (by invoking the typechecker functions that do this): >>> >>> https://github.com/ku-fpg/hermit/blob/master/src/HERMIT/Dictionary/GHC.hs#L223 >>> >>> The functions to run TcM computations inside CoreM are here: >>> >>> https://github.com/ku-fpg/hermit/blob/master/src/HERMIT/Monad.hs#L242 >>> and >>> https://github.com/ku-fpg/hermit/blob/master/src/HERMIT/GHC/Typechecker.hs#L47 >>> >>> Perhaps that will help get you started? >>> >>> I would like to push these interfaces back into the GHC API at some >>> point, but just haven't done it yet. >>> >>> HTH >>> Andrew >>> >>> On Mon, Aug 17, 2015 at 4:12 PM, Mike Izbicki <m...@izbicki.me> wrote: >>>> I'm not sure how either of those two functions can help me. The >>>> problem is that given an operator (e.g. `+`), I don't know the name of >>>> the dictionary that needs to be passed in as the first argument to the >>>> operator. I could probably hard code these names, but then the plugin >>>> wouldn't be able to work with alternative preludes. >>>> >>>> On Fri, Aug 7, 2015 at 11:20 PM, Edward Z. Yang <ezy...@mit.edu> wrote: >>>>> Hello Mike, >>>>> >>>>> Give importDecl from LoadIface a try, or maybe tcLookupGlobal if >>>>> you're in TcM. >>>>> >>>>> Edward >>>>> >>>>> Excerpts from Mike Izbicki's message of 2015-08-07 15:40:30 -0700: >>>>>> I'm trying to write a GHC plugin. The purpose of the plugin is to >>>>>> provide Haskell bindings to Herbie. Herbie >>>>>> (https://github.com/uwplse/herbie) is a program that takes a >>>>>> mathematical statement as input, and gives you a numerically stable >>>>>> formula to compute it as output. The plugin is supposed to automate >>>>>> this process for Haskell programs. >>>>>> >>>>>> I can convert the core expressions into a format for Herbie just fine. >>>>>> Where I'm having trouble is converting the output from Herbie back >>>>>> into core. Given a string that represents a numeric operator (e.g. >>>>>> "log" or "+"), I can get that converted into a Name that matches the >>>>>> Name of the version of that operator in scope at the location. But in >>>>>> order to create an Expr, I need to convert the Name into a Var. All >>>>>> the functions that I can find for this (e.g. mkGlobalVar) also require >>>>>> the type of the variable. But I can't find a way to figure out the >>>>>> Type given a Name. How can I do this? >>>> _______________________________________________ >>>> ghc-devs mailing list >>>> ghc-devs@haskell.org >>>> http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs >>>> >> _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
