question about GHC API on GHC plugin

Mike Izbicki mike at
Mon Aug 24 21:42:47 UTC 2015

Thanks!  Now one more question :)

The code Andrew Farmer showed me for getting dictionaries works great
when I have a concrete type (e.g. Float) I want a dictionary for.  But
now I'm working on polymorphic code and running into a problem.

Lets say I'm running the plugin on a function with signature `Floating
a => a -> a`, then the plugin has access to the `Floating` dictionary
for the type.  But if I want to add two numbers together, I need the
`Num` dictionary.  I know I should have access to `Num` since it's a
superclass of `Floating`.  How can I get access to these superclass

On Sat, Aug 22, 2015 at 7:35 AM, Ömer Sinan Ağacan <omeragacan at> wrote:
>> 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?
>     mkConApp intDataCon [mkIntLit dynFlags PUT_YOUR_INTEGER HERE]
>     mkConApp floatDataCon [mkFloatLit dynFlags PUT_YOUR_FLOAT_HERE]
> Similarly for other literals...

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