Simon Peyton Jones simonpj at
Tue Jan 26 10:55:08 UTC 2016

How are you getting on with tidying up substitutions.
I’ve done a bit in that direction myself:

commit 1c6d70c2121fd1126fcc2458bdbcc856e19598c2

Author: Simon Peyton Jones <simonpj at<mailto:simonpj at>>

Date:   Tue Jan 26 09:37:06 2016 +0000

    Kill off zipTopTCvSubst in favour of zipOpenTCvSubst
But there is more to do.
In particular, I note that substTys is not checked – but neither is it called substTysUnchecked.  It should be!  That will show up a bunch more cases, I think.
Another particular thing, arising from my patch, is that we can now do some renaming

·         zipOpenTCvSubst  -> zipTvSubst   (It only deals with tyvars)

·         zipOpenTCvSubstCoVars -> zipCvSubst   (it only deals with covars)

·         zipOpenTCvSubstBinders ->  zipTyBinderSubst  (it only deals with TyBinders, not covars)
I guess you’ll want to do similar things for the “mk” variants.
Anyway: good for you!  Let me know if you need help.

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