Injective type families

Ben Gamari ben at
Fri Jan 8 11:10:18 UTC 2016

Jan Stolarek <jan.stolarek at> writes:

> Ben,
>>   1. Should this feature be placed behind a LANGUAGE pragma?
> No, I don't think it should. I consider it a tiny addition to
> TypeFamilies that is not worth having its separate pragma. Injective
> TFs are fully backwards compatible, so no existing code
> will be broken.
That being said, it does claim new syntax and consequently would be
rather difficult to back out if we realize that this implementation
isn't the right direction. I don't have a strong opinion here, just
playing devil's advocate.

>>   2. Could you perhaps add some text to better motivate the feature in
>>      the users guide?
> Done. Tell me whether you like the new version.
Definitely better. Thanks for the quick turnaround!

> BTW do we still have nightly builds of User's Guide?
I have a script that I periodically run to push the documentation from
my test builds here:

It's updated pretty close to daily.


- Ben
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