Safe Haskell | None |
---|

This module is similar to Language.Syntactic.Sharing.Reify, but operates
on

rather than a general `AST`

(`HODomain`

dom p)`AST`

. The reason for
having this module is that when using `HODomain`

, it is important to do
simultaneous sharing analysis and `HOLambda`

reification. Obviously we cannot
do sharing analysis first (using
`reifyGraph`

from
Language.Syntactic.Sharing.Reify), since it needs to be able to look inside
`HOLambda`

. On the other hand, if we did `HOLambda`

reification first (using
`reify`

), we would destroy the sharing.

This module is based on the paper *Type-Safe Observable Sharing in Haskell*
(Andy Gill, 2009, http://dx.doi.org/10.1145/1596638.1596653).

- reifyGraphTop :: (forall a. ASTF (HODomain dom p pVar) a -> Bool) -> ASTF (HODomain dom p pVar) a -> IO (ASG (FODomain dom p pVar) a, VarId)
- reifyGraph :: (Syntactic a, Domain a ~ HODomain dom p pVar) => (forall a. ASTF (HODomain dom p pVar) a -> Bool) -> a -> IO (ASG (FODomain dom p pVar) (Internal a), VarId)

# Documentation

reifyGraphTop :: (forall a. ASTF (HODomain dom p pVar) a -> Bool) -> ASTF (HODomain dom p pVar) a -> IO (ASG (FODomain dom p pVar) a, VarId)Source

Convert a syntax tree to a sharing-preserving graph

:: (Syntactic a, Domain a ~ HODomain dom p pVar) | |

=> (forall a. ASTF (HODomain dom p pVar) a -> Bool) | A function that decides whether a given node can be shared |

-> a | |

-> IO (ASG (FODomain dom p pVar) (Internal a), VarId) |

Reifying an n-ary syntactic function to a sharing-preserving graph

This function is not referentially transparent (hence the `IO`

). However, it
is well-behaved in the sense that the worst thing that could happen is that
sharing is lost. It is not possible to get false sharing.