==

A type family to compute Boolean equality.
A type family to compute Boolean equality.
A type family to compute Boolean equality.
An infix alias for Equals.
Check if values are “the same”. Breaking from Elm, this relies on Haskell's Eq typeclass. For example:
data Foo = Bar | Baz deriving (Eq)
Like ==, but prints a counterexample when it fails.
Implication for properties: The resulting property holds if the first argument is False (in which case the test case is discarded), or if the given property holds. Note that using implication carelessly can severely skew test case distribution: consider using cover to make sure that your test data is still good quality.
Fails the test if the two arguments provided are not equal.
Check for equality.

Example usage

selectSPJ :: MonadIO m => ReaderT SqlBackend m [Entity User]
selectSPJ = selectList [UserName ==. "SPJ" ] []
The above query when applied on dataset-1, will produce this:
+-----+-----+-----+
|id   |name |age  |
+-----+-----+-----+
|1    |SPJ  |40   |
+-----+-----+-----+
The ==> operator can be used to express a restricting condition under which a property should hold. It corresponds to implication in the classical logic. Note that ==> resets the quantification context for its operands to the default (universal).
vertical concatenation
The ==> operator can be used to express a restricting condition under which a property should hold. It corresponds to implication in the classical logic. Note that ==> resets the quantification context for its operands to the default (universal).