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


-- | GHC plugin to make stream fusion more predictable.
--   
--   This plugin provides the programmer with a way to annotate certain
--   types using a <a>Fuse</a> pragma from the <a>fusion-plugin-types</a>
--   package. The programmer would annotate the types that are to be
--   eliminated by fusion. During the simplifier phase the plugin goes
--   through the relevant bindings and if one of these types are found
--   inside a binding then that binding is marked to be inlined
--   irrespective of the size.
--   
--   This plugin was primarily motivated by <a>streamly</a> but it can be
--   used in general.
@package fusion-plugin
@version 0.2.0


-- | Stream fusion depends on the GHC case-of-case transformations
--   eliminating intermediate constructors. Case-of-case transformation in
--   turn depends on inlining. During core-to-core transformations GHC may
--   create several internal bindings (e.g. join points) which may not get
--   inlined because their size is bigger than GHC's inlining threshold.
--   Even though we know that after fusion the resulting code would be
--   smaller and more efficient. The programmer cannot force inlining of
--   these bindings as there is no way for the programmer to address these
--   bindings at the source level because they are internal, generated
--   during core-to-core transformations. As a result stream fusion fails
--   unpredictably depending on whether GHC was able to inline the internal
--   bindings or not.
--   
--   <a>See GHC ticket #17075</a> for more details.
--   
--   This plugin provides the programmer with a way to annotate certain
--   types using a custom <a>Fuse</a> annotation. The programmer would
--   annotate the types that are to be eliminated by fusion via
--   case-of-case transformations. During the simplifier phase the plugin
--   goes through the relevant bindings and if one of these types are found
--   inside a binding then that binding is marked to be inlined
--   irrespective of the size.
--   
--   At the right places, fusion can provide dramatic performance
--   improvements (e.g. 10x) to the code.
module Fusion.Plugin
plugin :: Plugin
instance Outputable.Outputable Fusion.Plugin.Types.Fuse