From: simonpj@microsoft.com <unknown>
Date: Mon, 26 Oct 2009 09:47:56 +0000 (+0000)
Subject: Add a coercion optimiser, to reduce the size of coercion terms
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=48196c3c2a365ce085d0b0567cbd4ea047af59df;hp=48196c3c2a365ce085d0b0567cbd4ea047af59df

Add a coercion optimiser, to reduce the size of coercion terms

Coercion terms can get big (see Trac #2859 for example), so this
patch puts the infrastructure in place to optimise them:

  * Adds Coercion.optCoercion :: Coercion -> Coercion

  * Calls optCoercion in Simplify.lhs

The optimiser doesn't work right at the moment, so it is
commented out, but Tom is going to work on it.
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