Why are there no Show instances for internal types

[Ben Gamari]

Tom Sydney Kerckhove <syd.kerckhove at gmail.com> writes:

> On 19-03-17 02:08:56, Rahul Muttineni wrote:
>> Syd, can you tell us what kind of things you were trying to print out?
>
> Maybe I wasn't very clear.
> I'm trying to visualise the internal structure of some of the
> typechecker's output.
> I specifically do NOT need to see the output of Outputable's functions.
> They show the human-readibly version and not the internal structure.
>
Indeed I am sympathetic to this request. In my time working on GHC I
have written raw several variants of `Type -> SDoc`, each exposing
various levels of detail. These are handy and can be a good way to gain
insight into the AST, but I feel like it is hard to come up with
something that is generally applicable; I find each time I need to
expose slightly different details about the internal structure of the
representation.

Cheers,

- Ben

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