In Haskell, it's a ForeignPtr --- you can't see "inside" it except by FFI calls.  Although Duncan is correct and you can use an FFI preprocessor to access the portable fields, and simply not provide access to the rest from Haskell.

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brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery@kf8nh.com

system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu

electrical and computer engineering, carnegie mellon university    KF8NH