[Haskell-cafe] bytestring vs. uvector

Bulat Ziganshin bulat.ziganshin at gmail.com
Tue Mar 10 16:55:35 EDT 2009

Hello Don,

Tuesday, March 10, 2009, 11:01:31 PM, you wrote:

>> if uavector use ghc's built-in unboxed array operations (as
>> Data.Array.Unboxed does) then it's necessarily bounded to types
>> supported by those operations

> And what is Storable limited to?

> Ultimately they're all limited to the primops for reading and writing,

the full story:

ghc up to 6.6 has slow access to ForeignArrays, as you may recall

therefore, those primitives was added. ByteArra# plus those primitives
was the only way to have unboxed arrays with fast access

starting with 6.6, ForeignArray access is no-op, so we can just use
obvious Ptr operations (via Storable class) to get unboxed arrays fast
access. so, no more need for those special ByteArray# access operations

but Array library still old, so any effort based on its spources, got
the same restrictions

also, ByteArray# may be unpinned, but afaik, this isn't really
important - it can be coerced to Ptr for the period of one operation

Best regards,
 Bulat                            mailto:Bulat.Ziganshin at gmail.com

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