[ghc-steering-committee] Remove TypeOperators => NoStarIsType "migration" (#146); Recommendation: accept

[Ben Gamari]

Hi everyone,

We are being asked to consider pull request #146. This proposal is an
amendment to the accepted Proposal 0020 [1], removing a migration
mechanism which was found in practice to hurt more than help.

Specifically, proposal 0020 currently specifies a migration period
during which the -XNoStarIsType extension (which proposal 0020
introduces) will be implied by -XTypeOperators. The motivation for this
was to ease the transition for packages which use * as a binary type
operator.

In practice it turned out that a significant number of packages are
broken by this migration mechanism. Specifically, many packages use
* in kind signatures while also enabling TypeOperators.

The proposed amendment removes TypeOperator's implication of
NoStarIsType. To be clear, this is ultimately a trade-off between
optimising for users of (*) as a binary operator and users of * ~ Type.
It just so happens that there are far more of the latter. Consequently,
my recommendation is to accept the modified proposal.

Cheers,

- Ben


[1] https://github.com/ghc-proposals/ghc-proposals/pull/83
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 487 bytes
Desc: not available
URL: <http://mail.haskell.org/pipermail/ghc-steering-committee/attachments/20180625/66dbfa59/attachment.sig>