{-# LANGUAGE Safe #-} ----------------------------------------------------------------------------- -- | -- Module : System.Mem.StableName -- Copyright : (c) The University of Glasgow 2001 -- License : BSD-style (see the file libraries/base/LICENSE) -- -- Maintainer : libraries@haskell.org -- Stability : experimental -- Portability : non-portable -- -- Stable names are a way of performing fast ( \(\mathcal{O}(1)\) ), -- not-quite-exact comparison between objects. -- -- Stable names solve the following problem: suppose you want to build -- a hash table with Haskell objects as keys, but you want to use -- pointer equality for comparison; maybe because the keys are large -- and hashing would be slow, or perhaps because the keys are infinite -- in size. We can\'t build a hash table using the address of the -- object as the key, because objects get moved around by the garbage -- collector, meaning a re-hash would be necessary after every garbage -- collection. -- ------------------------------------------------------------------------------- module System.Mem.StableName ( -- * Stable Names StableName, makeStableName, hashStableName, eqStableName ) where import GHC.StableName