[Git][ghc/ghc][master] User's guide: Clarify overlapping instance candidate elimination

[Marge Bot (@marge-bot)]

Marge Bot pushed to branch master at Glasgow Haskell Compiler / GHC


Commits:
b69461a0 by Jason Shipman at 2023-01-30T21:21:50-05:00
User's guide: Clarify overlapping instance candidate elimination

This commit updates the user's guide section on overlapping instance candidate
elimination to use "or" verbiage instead of "either/or" in regards to the
current pair of candidates' being overlappable or overlapping. "Either IX is
overlappable, or IY is overlapping" can cause confusion as it suggests "Either
IX is overlappable, or IY is overlapping, but not both".

This was initially discussed on this Discourse topic:

https://discourse.haskell.org/t/clarification-on-overlapping-instance-candidate-elimination/5677

- - - - -


1 changed file:

- docs/users_guide/exts/instances.rst


Changes:

=====================================
docs/users_guide/exts/instances.rst
=====================================
@@ -486,8 +486,8 @@ like this:
    -  :math:`IY` is strictly more specific than :math:`IX`.  That
       is, :math:`IY` is a substitution instance of :math:`IX` but not vice versa.
 
-   -  Either :math:`IX` is *overlappable*, or :math:`IY` is *overlapping*. (This
-      "either/or" design, rather than a "both/and" design, allow a
+   -  :math:`IX` is *overlappable* or :math:`IY` is *overlapping*. (This
+      "or" design, rather than an "and" design, allows a
       client to deliberately override an instance from a library,
       without requiring a change to the library.)
 



View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/b69461a06166d2b1c600df87b87656d09122fb7c

-- 
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/b69461a06166d2b1c600df87b87656d09122fb7c
You're receiving this email because of your account on gitlab.haskell.org.


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/ghc-commits/attachments/20230130/3959160c/attachment.html>