Traverse better #88
Traverse better #88
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Do we still support pre-7.2 GHC, or can I kill that CPP? |
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We don’t support pre 7.2, and in fact I think because 7.2 was just a tech
preview release we may only currently support 7.4 onwards ? I could be
wrong though
…On Sun, Mar 18, 2018 at 2:44 AM David Feuer ***@***.***> wrote:
Do we still support pre-7.2 GHC, or can I kill that CPP?
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Yep, we only support GHC 7.4 and later (see #83 (comment)), so go ahead and kill that CPP. |
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I amended the commit to avoid adding 7.2-related CPP, and added a commit to remove the rest of said CPP from |
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Hrm..... Turned out what I was doing to turn the |
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Actually, I think I see how to fix that. It's a bit ugly, and only available for recent GHC, but I think I'll do it anyway. One more fix incoming... |
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(Ugly as in ugly source code. It's actually cleaner in a sense. |
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Oh, actually, I can make it work for older versions too, with a perfectly safe |
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Eh, I changed my mind. Source code gets too messy, and the benefits seem too limited. I think this is ready to merge as is. |
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Instead of traversing a list and then converting to an array, be more direct. GHC seems to be able to optimize this better, at least in common cases. Addresses haskell#85.
* Add `unsafeTraverseArray` and `unsafeTraverseSmallArray` functions. * Add rewrite rules to use them for traversals in `ST s` and `IO`. * Add rewrite rules for traversing in `Identity`.
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RyanGlScott
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This looks entirely plausible to me. Like foldl, it might be nice to write some QuickCheck tests for this, but I'd be fine if you want to merge this now.
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Instead of traversing a list and then converting to an array,
be more direct. GHC seems to be able to optimize this better,
at least in common cases.
Add functions for traversing arrays in "affine" primitive monads: monad transformer stacks built from
StateT,ReaderT,WriterT,RWST,ExceptT,Stream (Of a), etc., but not, for example,ListT(done right or otherwise) orLogicT.Fixes #85.