Modulerecord-hasfield-1.0.1Haskell2010

GHC.Records.Extra

Extensions over a future version of GHC.Records. Provides the function modifyField plus the orphan instances:

HasField '(x1,x2) for selecting first the x1 field, then the x2 field. Available for () and tuples up to arity 5.
HasField "_1" (a,b) a for selecting the first compomnent of a pair, plus similarly for all fields up of all tuples up to arity 5.

Using these functions together you get:

modifyField @'("_1","_2") negate ((1,2),3,4,5) == ((1,-2),3,4,5)

module GHC.Records.Compat

valuemodifyField :: HasField x r a => r -> (a -> a) -> r

Modify a field in a record.

Orphan instances

19 instances

HasField '() a a
HasField "_1" (a, b) a
HasField "_2" (a, b) b
HasField "_1" (a, b, c) a
HasField "_2" (a, b, c) b
HasField "_3" (a, b, c) c
HasField "_1" (a, b, c, d) a
HasField "_2" (a, b, c, d) b
HasField "_3" (a, b, c, d) c
HasField "_4" (a, b, c, d) d
HasField "_1" (a, b, c, d, e) a
HasField "_2" (a, b, c, d, e) b
HasField "_3" (a, b, c, d, e) c
HasField "_4" (a, b, c, d, e) d
HasField "_5" (a, b, c, d, e) e
(a1 ~ r2, HasField x1 r1 a1, HasField x2 r2 a2) => HasField '(x1, x2) r1 a2
(a1 ~ r2, a2 ~ r3, HasField x1 r1 a1, HasField x2 r2 a2, HasField x3 r3 a3) => HasField '(x1, x2, x3) r1 a3
(a1 ~ r2, a2 ~ r3, a3 ~ r4, HasField x1 r1 a1, HasField x2 r2 a2, HasField x3 r3 a3, HasField x4 r4 a4) => HasField '(x1, x2, x3, x4) r1 a4
(a1 ~ r2, a2 ~ r3, a3 ~ r4, a4 ~ r5, HasField x1 r1 a1, HasField x2 r2 a2, HasField x3 r3 a3, HasField x4 r4 a4, HasField x5 r5 a5) => HasField '(x1, x2, x3, x4, x5) r1 a5