This library contains common accessors.
onEach : Accessors.Relation super sub wrap -> Accessors.Relation (List super) sub (List wrap)
This accessor combinator lets you access values inside lists.
listRecord = { foo = [ {bar = 2}
, {bar = 3}
, {bar = 4}
]
}
get (foo << onEach << bar) listRecord
-- returns [2, 3, 4]
over (foo << onEach << bar) ((+) 1) listRecord
-- returns {foo = [{bar = 3}, {bar = 4}, {bar = 5}]}
try : Accessors.Relation super sub wrap -> Accessors.Relation (Maybe super) sub (Maybe wrap)
This accessor combinator lets you access values inside Maybe.
maybeRecord = { foo = Just {bar = 2}
, qux = Nothing
}
get (foo << try << bar) maybeRecord
-- returns Just 2
get (qux << try << bar) maybeRecord
-- returns Nothing
over (foo << try << bar) ((+) 1) maybeRecord
-- returns {foo = Just {bar = 3}, qux = Nothing}
over (qux << try << bar) ((+) 1) maybeRecord
-- returns {foo = Just {bar = 2}, qux = Nothing}
dictEntry : comparable -> Accessors.Relation (Maybe v) reachable wrap -> Accessors.Relation (Dict comparable v) reachable wrap
This accessor combinator lets you access Dict members.
In terms of accessors, think of Dicts as records where each field is a Maybe.
dict = Dict.fromList [("foo", {bar = 2})]
get (dictEntry "foo") dict
-- returns Just {bar = 2}
get (dictEntry "baz" dict)
-- returns Nothing
get (dictEntry "foo" << try << bar) dict
-- returns Just 2
set (dictEntry "foo") Nothing dict
-- returns Dict.remove "foo" dict
set (dictEntry "baz" << try << bar) 3 dict
-- returns dict