Arg -package:parseargs

Arg isn't itself a Semigroup in its own right, but it can be placed inside Min and Max to compute an arg min or arg max. In the event of ties, the leftmost qualifying Arg is chosen; contrast with the behavior of minimum and maximum for many other types, where ties are broken by considering elements to the left in the structure to be less than elements to the right.

Examples

>>> minimum [ Arg (x * x) x | x <- [-10 .. 10] ]
Arg 0 0

>>> maximum [ Arg (-0.2*x^2 + 1.5*x + 1) x | x <- [-10 .. 10] ]
Arg 3.8 4.0

>>> minimum [ Arg (-0.2*x^2 + 1.5*x + 1) x | x <- [-10 .. 10] ]
Arg (-34.0) (-10.0)

Type synonym for expressions that occur in function argument positions. Only Arg should contain a Type at top level, general Expr should not

An unnamed argument. Anything not starting with - is considered an argument, apart from "-" which is considered to be the argument "-", and any arguments following "--". For example:

programname arg1 -j - --foo arg3 -- -arg4 --arg5=1 arg6

Would have the arguments:

["arg1","-","arg3","-arg4","--arg5=1","arg6"]

Arg isn't itself a Semigroup in its own right, but it can be placed inside Min and Max to compute an arg min or arg max.

>>> minimum [ Arg (x * x) x | x <- [-10 .. 10] ]
Arg 0 0

Arg isn't itself a Semigroup in its own right, but it can be placed inside Min and Max to compute an arg min or arg max.

>>> minimum [ Arg (x * x) x | x <- [-10 .. 10] ]
Arg 0 0

Constraint helper for types with parameters Usage:

data A a = A a
deriving (Generic)
instance (Arg (A a) a, Arbitrary a) => Arbitrary (A a) where
arbitrary = genericArbitrary
shrink = genericShrink

Maps a name to the foreign type that belongs to the annotated value. Used for header args, query args, and capture args.

Match on an argument without specifying its name. See also: arg.

An argument applied to a function data constructor primitive.

Input hole

instance Arg A where allows functions which take As to be reified