/Prelude-v21.1.0/JSON/omitNullFields.dhall

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This utility omits all null record fields, which is often the idiomatic way for a configuration to encode absent fields

Examples

  omitNullFields
( JSON.object
( toMap
{ array = JSON.array [ JSON.object (toMap { null = JSON.null }) ] }
)
)
≡ JSON.object
( toMap
{ array =
JSON.array
[ JSON.object ([] : List { mapKey : Text, mapValue : JSON.Type })
]
}
)
omitNullFields (JSON.array [ JSON.null ]) ≡ JSON.array [ JSON.null ]

Source

{-|
This utility omits all `null` record fields, which is often the idiomatic way
for a configuration to encode absent fields
-}
let JSON =
./core.dhall sha256:5dc1135d5481cfd6fde625aaed9fcbdb7aa7c14f2e76726aa5fdef028a5c10f5
? ./core.dhall

let List/concatMap =
../List/concatMap.dhall sha256:3b2167061d11fda1e4f6de0522cbe83e0d5ac4ef5ddf6bb0b2064470c5d3fb64
? ../List/concatMap.dhall

let List/map =
../List/map.dhall sha256:dd845ffb4568d40327f2a817eb42d1c6138b929ca758d50bc33112ef3c885680
? ../List/map.dhall

let omitNullFields
: JSON.Type → JSON.Type
= λ(old : JSON.Type) →
λ(JSON : Type) →
λ ( json
: { array : List JSONJSON
, bool : Bool → JSON
, double : Double → JSON
, integer : Integer → JSON
, null : JSON
, object : List { mapKey : Text, mapValue : JSON } → JSON
, string : Text → JSON
}
) →
let result =
old
{ value : JSON, isNull : Bool }
{ string =
λ(x : Text) → { value = json.string x, isNull = False }
, double =
λ(x : Double) → { value = json.double x, isNull = False }
, integer =
λ(x : Integer) → { value = json.integer x, isNull = False }
, object =
λ ( keyValues
: List
{ mapKey : Text
, mapValue : { value : JSON, isNull : Bool }
}
) →
let value =
json.object
( List/concatMap
{ mapKey : Text
, mapValue : { value : JSON, isNull : Bool }
}
{ mapKey : Text, mapValue : JSON }
( λ ( keyValue
: { mapKey : Text
, mapValue :
{ value : JSON, isNull : Bool }
}
) →
if keyValue.mapValue.isNull
then [] : List
{ mapKey : Text
, mapValue : JSON
}
else [ keyValue.{ mapKey }
∧ { mapValue =
keyValue.mapValue.value
}
]
)
keyValues
)

in { value, isNull = False }
, array =
λ(xs : List { value : JSON, isNull : Bool }) →
let value =
json.array
( List/map
{ value : JSON, isNull : Bool }
JSON
( λ(x : { value : JSON, isNull : Bool }) →
x.value
)
xs
)

in { value, isNull = False }
, bool = λ(x : Bool) → { value = json.bool x, isNull = False }
, null = { value = json.null, isNull = True }
}

in result.value

let property =
λ(a : Text) →
λ(b : Double) →
λ(c : Bool) →
assert
: omitNullFields
( JSON.object
( toMap
{ string = JSON.string a
, double = JSON.double b
, bool = JSON.bool c
, null = JSON.null
}
)
)
JSON.object
( toMap
{ string = JSON.string a
, double = JSON.double b
, bool = JSON.bool c
}
)

let example =
assert
: omitNullFields
( JSON.object
( toMap
{ array =
JSON.array [ JSON.object (toMap { null = JSON.null }) ]
}
)
)
JSON.object
( toMap
{ array =
JSON.array
[ JSON.object
([] : List { mapKey : Text, mapValue : JSON.Type })
]
}
)

let example =
assert
: omitNullFields (JSON.array [ JSON.null ]) ≡ JSON.array [ JSON.null ]

in omitNullFields