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| author | Vladislav Zavialov <vlad.z.4096@gmail.com> | 2019-07-24 17:17:47 +0300 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2019-07-26 00:58:15 -0400 |
| commit | 00d9d28405a5983ae40a1815a146fb27abca10e8 (patch) | |
| tree | f0d77ea51aadd9f27b296e36191de80958a3d380 /libraries/template-haskell/Language/Haskell/TH/Syntax.hs | |
| parent | aae0457f412aa40dd192ca2cbea565ea60b182ec (diff) | |
| download | haskell-00d9d28405a5983ae40a1815a146fb27abca10e8.tar.gz | |
TemplateHaskell: reifyType (#16976)
Diffstat (limited to 'libraries/template-haskell/Language/Haskell/TH/Syntax.hs')
| -rw-r--r-- | libraries/template-haskell/Language/Haskell/TH/Syntax.hs | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/libraries/template-haskell/Language/Haskell/TH/Syntax.hs b/libraries/template-haskell/Language/Haskell/TH/Syntax.hs index f79a8e2b0c..72eadbff91 100644 --- a/libraries/template-haskell/Language/Haskell/TH/Syntax.hs +++ b/libraries/template-haskell/Language/Haskell/TH/Syntax.hs @@ -76,6 +76,7 @@ class (MonadIO m, Fail.MonadFail m) => Quasi m where -- True <=> type namespace, False <=> value namespace qReify :: Name -> m Info qReifyFixity :: Name -> m (Maybe Fixity) + qReifyType :: Name -> m Type qReifyInstances :: Name -> [Type] -> m [Dec] -- Is (n tys) an instance? -- Returns list of matching instance Decs @@ -132,6 +133,7 @@ instance Quasi IO where qLookupName _ _ = badIO "lookupName" qReify _ = badIO "reify" qReifyFixity _ = badIO "reifyFixity" + qReifyType _ = badIO "reifyFixity" qReifyInstances _ _ = badIO "reifyInstances" qReifyRoles _ = badIO "reifyRoles" qReifyAnnotations _ = badIO "reifyAnnotations" @@ -429,6 +431,14 @@ example, if the function @foo@ has the fixity declaration @infixr 7 foo@, then reifyFixity :: Name -> Q (Maybe Fixity) reifyFixity nm = Q (qReifyFixity nm) +{- | @reifyType nm@ attempts to find the type or kind of @nm@. For example, +@reifyType 'not@ returns @Bool -> Bool@, and +@reifyType ''Bool@ returns @Type@. +This works even if there's no explicit signature and the type or kind is inferred. +-} +reifyType :: Name -> Q Type +reifyType nm = Q (qReifyType nm) + {- | @reifyInstances nm tys@ returns a list of visible instances of @nm tys@. That is, if @nm@ is the name of a type class, then all instances of this class at the types @tys@ are returned. Alternatively, if @nm@ is the name of a data family or type family, @@ -620,6 +630,7 @@ instance Quasi Q where qRecover = recover qReify = reify qReifyFixity = reifyFixity + qReifyType = reifyType qReifyInstances = reifyInstances qReifyRoles = reifyRoles qReifyAnnotations = reifyAnnotations |