Interested to help with error messages

Ben Gamari ben at
Sat Jun 3 16:22:06 UTC 2017

Alan & Kim Zimmerman <alan.zimm at> writes:

> Thanks Ben, a great summary.  Is there a Wiki page for this? It feels like
> it should be on one, so we can easily comment/update the individual points.
Here you are:

In the interest of time I essentially just pasted my response. Feel free
to hack it up to your heart's content. 

> In terms of the pretty-printer and its string type. Perhaps we could
> backpackify it to use,
> and then specialise the GHC version to FastString etc.
Sounds plausible.

Relatedly, I always found it a bit odd that we used
FastString for Doc literals. Namely we have to pay the cost of
hashing the string, despite the fact that we will never use the hash.
It's likely a tiny effect (hashing is quite quick), but it still seems

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