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authorTom Smeding <tom@tomsmeding.com>2024-11-13 20:20:30 +0100
committerTom Smeding <tom@tomsmeding.com>2024-11-13 20:20:30 +0100
commitbf4a469f369f1b8c6b1c2d7cc6907177405603f4 (patch)
tree2f62400251662a7285aeba7fff0b807432f75fff /src/Data/Array/Nested/Internal/Shape.hs
parentdd859ea30b187880e49c0cb005cc6006a1e3bbc1 (diff)
Add withKnownSh{S,X}
Diffstat (limited to 'src/Data/Array/Nested/Internal/Shape.hs')
-rw-r--r--src/Data/Array/Nested/Internal/Shape.hs4
1 files changed, 4 insertions, 0 deletions
diff --git a/src/Data/Array/Nested/Internal/Shape.hs b/src/Data/Array/Nested/Internal/Shape.hs
index b7bbf4c..59f2c9a 100644
--- a/src/Data/Array/Nested/Internal/Shape.hs
+++ b/src/Data/Array/Nested/Internal/Shape.hs
@@ -34,6 +34,7 @@ import Data.Kind (Type, Constraint)
import Data.Monoid (Sum(..))
import Data.Proxy
import Data.Type.Equality
+import GHC.Exts (withDict)
import GHC.IsList (IsList)
import GHC.IsList qualified as IsList
import GHC.TypeLits
@@ -558,6 +559,9 @@ class KnownShS sh where knownShS :: ShS sh
instance KnownShS '[] where knownShS = ZSS
instance (KnownNat n, KnownShS sh) => KnownShS (n : sh) where knownShS = natSing :$$ knownShS
+withKnownShS :: forall sh r. ShS sh -> (KnownShS sh => r) -> r
+withKnownShS sh = withDict @(KnownShS sh) sh
+
shsKnownShS :: ShS sh -> Dict KnownShS sh
shsKnownShS ZSS = Dict
shsKnownShS (SNat :$$ sh) | Dict <- shsKnownShS sh = Dict