From: dimitris@microsoft.com <unknown>
Date: Thu, 31 Mar 2011 10:26:34 +0000 (+0000)
Subject: Introducing a datatype for WorkLists that properly prioritizes equalities.
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=5cfe9e92a92201043d5dbb1c4e10fef0ed0d9f49;hp=5cfe9e92a92201043d5dbb1c4e10fef0ed0d9f49

Introducing a datatype for WorkLists that properly prioritizes equalities.

We were not prioritizing the interaction of equalities in the worklist, because
pre-canonicalization solved the constraints one by one, in their arrival order.
This patch fixes this, so it's a generally useful improvement, mainly for
efficiency. It makes #4981 go away, although it's not a definite answer to the
cause of the problem. See discussion on Trac.
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