-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Provides access to the dynamic pointer tagging bits used by GHC.
--   
--   Provides access to the dynamic pointer tagging bits used by GHC.
@package tag-bits
@version 0.1.1

module Data.TagBits

-- | Inspect the dynamic pointer tagging bits of a closure. This is an
--   impure function that relies on GHC internals and may falsely return 0,
--   but should never give the wrong tag number if it returns a non-0
--   value.
unsafeGetTagBits :: a -> Word

-- | Returns a guess as to whether or not a value has been evaluated. This
--   is an impure function that relies on GHC internals and will return
--   false negatives, but no false positives. This is unsafe as the value
--   of this function will vary (from False to True) over the course of
--   otherwise pure invocations! This first attempts to check the tag bits
--   of the pointer, and then falls back on inspecting the info table for
--   the closure type.
unsafeIsEvaluated :: a -> Bool