46 lines
1.6 KiB
Haskell
46 lines
1.6 KiB
Haskell
module Database.Esqueleto.Utils where
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import ClassyPrelude.Yesod hiding (isInfixOf, (||.))
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import Data.Foldable as F
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import Database.Esqueleto as E
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--
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-- Description : Convenience for using @Esqueleto@,
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-- intended to be imported qualified
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-- just like Esqueleto
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-- ezero = E.val (0 :: Int64)
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-- | Often needed with this concrete type
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true :: E.SqlExpr (E.Value Bool)
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true = E.val True
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-- | Often needed with this concrete type
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false :: E.SqlExpr (E.Value Bool)
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false = E.val False
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-- | Check if the first string is contained in the text derived from the second argument
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isInfixOf :: (E.Esqueleto query expr backend, E.SqlString s2) =>
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Text -> expr (E.Value s2) -> expr (E.Value Bool)
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isInfixOf needle strExpr = E.castString strExpr `E.ilike` (E.%) E.++. E.val needle E.++. (E.%)
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hasInfix :: (E.Esqueleto query expr backend, E.SqlString s2) =>
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expr (E.Value s2) -> Text -> expr (E.Value Bool)
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hasInfix = flip isInfixOf
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-- | Given a test and a set of values, check whether anyone succeeds the test
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-- WARNING: SQL leaves it explicitely unspecified whether || is short curcuited (i.e. lazily evaluated)
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any :: Foldable f =>
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(a -> SqlExpr (E.Value Bool)) -> f a -> SqlExpr (E.Value Bool)
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any test = F.foldr (\needle acc -> acc ||. test needle) false
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-- | Given a test and a set of values, check whether all succeeds the test
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-- WARNING: SQL leaves it explicitely unspecified whether && is short curcuited (i.e. lazily evaluated)
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all :: Foldable f =>
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(a -> SqlExpr (E.Value Bool)) -> f a -> SqlExpr (E.Value Bool)
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all test = F.foldr (\needle acc -> acc &&. test needle) true
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