-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Generic pattern predicates
--   
--   Generate predicates of type (t → Bool) from constructors or patterns
--   of type t. Uses either Template Haskell or instances of Generic or
--   Typeable. Generating predicates from arbitrary patterns requires TH.
@package is
@version 0.4

module Data.Generics.Is.TH

-- | Given a constructor (or pattern synonym) for type <tt>T</tt>,
--   <a>is</a> generates a function of type <tt>T → Bool</tt>.
--   
--   The function evaluates its argument to WHNF, and returns <a>True</a>
--   if the head constructor matches the given one, <a>False</a> otherwise.
--   
--   <pre>
--   &gt;&gt;&gt; $(is 'Just) (Just 5)
--   True
--   </pre>
is :: Name -> Q Exp

-- | <pre>
--   $(isNot 'Con) ≡ not . $(is 'Con)
--   </pre>
--   
--   <pre>
--   &gt;&gt;&gt; $(isNot '(:)) [1,2,3]
--   False
--   </pre>
isNot :: Name -> Q Exp

-- | Given a pattern for type <tt>T</tt>, <a>isP</a> generates a function
--   of type <tt>T → Bool</tt>.
--   
--   The function returns <a>True</a> if the expression matches the
--   pattern; a and <a>False</a> otherwise.
--   
--   <pre>
--   $(isP [p| Con{} |]) ≡ $(is 'Con)
--   </pre>
--   
--   <pre>
--   &gt;&gt;&gt; $(isP [p| Just{} |]) Nothing
--   False
--   </pre>
isP :: Q Pat -> Q Exp

-- | <pre>
--   $(isNotP [p| P |]) ≡ not . $(isP [p| P |])
--   </pre>
isNotP :: Q Pat -> Q Exp

-- | Generate predicates of the form <tt>isK</tt>
--   
--   <pre>
--   &gt;&gt;&gt; $(makePredicates ''E)
--   
--   &gt;&gt;&gt; isPlus (Plus (Lit 1) (Lit 2))
--   True
--   </pre>
makePredicates :: Name -> Q [Dec]

-- | Generate predicates of the form <tt>isNotK</tt>
--   
--   <pre>
--   &gt;&gt;&gt; $(makePredicatesNot ''E)
--   
--   &gt;&gt;&gt; isNotAnd (Showable True)
--   True
--   </pre>
makePredicatesNot :: Name -> Q [Dec]

-- | Generate predicates of both forms, <tt>isK</tt> and <tt>isNotK</tt>
--   
--   <pre>
--   $(makePredicatesAll ''E) ≡ $(makePredicates ''E) ; $(makePredicatesNot ''E)
--   </pre>
makePredicatesAll :: Name -> Q [Dec]

module Data.Generics.Is.Generic
is :: forall c a. (Constructs c a, Generic a, EqHead (Rep a)) => c -> a -> Bool
isNot :: forall c a. (Constructs c a, Generic a, EqHead (Rep a)) => c -> a -> Bool

module Data.Generics.Is.Data
is :: forall a b. (Constructs a b, Data b) => a -> b -> Bool
isNot :: forall a b. (Constructs a b, Data b) => a -> b -> Bool


-- | <i>Deprecated: Import <a>Data.Generics.Is.TH</a> directly, or port
--   your code to using <a>Data.Generics.Is.Generic</a>.</i>
module Data.Generics.Is