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| author | Facundo Domínguez <facundo.dominguez@tweag.io> | 2014-12-09 18:10:18 -0600 |
|---|---|---|
| committer | Austin Seipp <austin@well-typed.com> | 2014-12-09 19:59:27 -0600 |
| commit | fc45f32491313d2a44e72d8d59cdf95b1660189d (patch) | |
| tree | 853de68ce9feca6a61d2b540ef13fc03162740de /libraries/template-haskell/Language | |
| parent | e5974f8f53de4c97cfaad228eedfca8b31b53887 (diff) | |
| download | haskell-fc45f32491313d2a44e72d8d59cdf95b1660189d.tar.gz | |
Implement -XStaticValues
Summary:
As proposed in [1], this extension introduces a new syntactic form
`static e`, where `e :: a` can be any closed expression. The static form
produces a value of type `StaticPtr a`, which works as a reference that
programs can "dereference" to get the value of `e` back. References are
like `Ptr`s, except that they are stable across invocations of a
program.
The relevant wiki pages are [2, 3], which describe the motivation/ideas
and implementation plan respectively.
[1] Jeff Epstein, Andrew P. Black, and Simon Peyton-Jones. Towards
Haskell in the cloud. SIGPLAN Not., 46(12):118–129, September 2011. ISSN
0362-1340.
[2] https://ghc.haskell.org/trac/ghc/wiki/StaticPointers
[3] https://ghc.haskell.org/trac/ghc/wiki/StaticPointers/ImplementationPlan
Authored-by: Facundo Domínguez <facundo.dominguez@tweag.io>
Authored-by: Mathieu Boespflug <m@tweag.io>
Authored-by: Alexander Vershilov <alexander.vershilov@tweag.io>
Test Plan: `./validate`
Reviewers: hvr, simonmar, simonpj, austin
Reviewed By: simonpj, austin
Subscribers: qnikst, bgamari, mboes, carter, thomie, goldfire
Differential Revision: https://phabricator.haskell.org/D550
GHC Trac Issues: #7015
Diffstat (limited to 'libraries/template-haskell/Language')
4 files changed, 8 insertions, 1 deletions
diff --git a/libraries/template-haskell/Language/Haskell/TH.hs b/libraries/template-haskell/Language/Haskell/TH.hs index 050ac85272..b3ac97b5a4 100644 --- a/libraries/template-haskell/Language/Haskell/TH.hs +++ b/libraries/template-haskell/Language/Haskell/TH.hs @@ -90,7 +90,7 @@ module Language.Haskell.TH( normalB, guardedB, normalG, normalGE, patG, patGE, match, clause, -- *** Expressions - dyn, global, varE, conE, litE, appE, uInfixE, parensE, + dyn, global, varE, conE, litE, appE, uInfixE, parensE, staticE, infixE, infixApp, sectionL, sectionR, lamE, lam1E, lamCaseE, tupE, condE, multiIfE, letE, caseE, appsE, listE, sigE, recConE, recUpdE, stringE, fieldExp, diff --git a/libraries/template-haskell/Language/Haskell/TH/Lib.hs b/libraries/template-haskell/Language/Haskell/TH/Lib.hs index bfba99a487..8aed78d70b 100644 --- a/libraries/template-haskell/Language/Haskell/TH/Lib.hs +++ b/libraries/template-haskell/Language/Haskell/TH/Lib.hs @@ -296,6 +296,10 @@ stringE = litE . stringL fieldExp :: Name -> ExpQ -> Q (Name, Exp) fieldExp s e = do { e' <- e; return (s,e') } +-- | @staticE x = [| static x |]@ +staticE :: ExpQ -> ExpQ +staticE = fmap StaticE + -- ** 'arithSeqE' Shortcuts fromE :: ExpQ -> ExpQ fromE x = do { a <- x; return (ArithSeqE (FromR a)) } diff --git a/libraries/template-haskell/Language/Haskell/TH/Ppr.hs b/libraries/template-haskell/Language/Haskell/TH/Ppr.hs index 5f3a0c6c9b..0f828eb98b 100644 --- a/libraries/template-haskell/Language/Haskell/TH/Ppr.hs +++ b/libraries/template-haskell/Language/Haskell/TH/Ppr.hs @@ -172,6 +172,8 @@ pprExp _ (ListE es) = brackets $ sep $ punctuate comma $ map ppr es pprExp i (SigE e t) = parensIf (i > noPrec) $ ppr e <+> text "::" <+> ppr t pprExp _ (RecConE nm fs) = ppr nm <> braces (pprFields fs) pprExp _ (RecUpdE e fs) = pprExp appPrec e <> braces (pprFields fs) +pprExp i (StaticE e) = parensIf (i >= appPrec) $ + text "static"<+> pprExp appPrec e pprFields :: [(Name,Exp)] -> Doc pprFields = sep . punctuate comma . map (\(s,e) -> ppr s <+> equals <+> ppr e) diff --git a/libraries/template-haskell/Language/Haskell/TH/Syntax.hs b/libraries/template-haskell/Language/Haskell/TH/Syntax.hs index 0e5ced9152..425834b164 100644 --- a/libraries/template-haskell/Language/Haskell/TH/Syntax.hs +++ b/libraries/template-haskell/Language/Haskell/TH/Syntax.hs @@ -1160,6 +1160,7 @@ data Exp | SigE Exp Type -- ^ @{ e :: t }@ | RecConE Name [FieldExp] -- ^ @{ T { x = y, z = w } }@ | RecUpdE Exp [FieldExp] -- ^ @{ (f x) { z = w } }@ + | StaticE Exp -- ^ @{ static e }@ deriving( Show, Eq, Data, Typeable, Generic ) type FieldExp = (Name,Exp) |