/Prelude-v23.0.0/JSON/renderAs.dhall

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Render a JSON value as Text in either JSON or YAML format.

Source

--| Render a `JSON` value as `Text` in either JSON or YAML format.
let JSON =
missing sha256:5dc1135d5481cfd6fde625aaed9fcbdb7aa7c14f2e76726aa5fdef028a5c10f5
? ./core.dhall

let Function/identity =
missing sha256:f78b96792b459cb664f41c6119bd8897dd04353a3343521d436cd82ad71cb4d4
? ../Function/identity.dhall

let Text/concatMap =
missing sha256:7a0b0b99643de69d6f94ba49441cd0fa0507cbdfa8ace0295f16097af37e226f
? ../Text/concatMap.dhall

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

let NonEmpty =
missing sha256:e2e247455a858317e470e0e4affca8ac07f9f130570ece9cb7ac1f4ea3deb87f
? ../NonEmpty/Type.dhall

let NonEmpty/toList =
missing sha256:0977fe14b77232a4451dcf409c43df4589c4b3cdde7b613aab8df183be1b53f5
? ../NonEmpty/toList.dhall

let NonEmpty/concat =
missing sha256:6d55181938c06c6b806877028f6a241912e9c0935d9a10dd958775bf21e0f64d
? ../NonEmpty/concat.dhall

let NonEmpty/map =
missing sha256:93d53afe874bb2eed946c21ca5ada3c9716b7d00e6d8edfaba6484cd9c5a00bd
? ../NonEmpty/map.dhall

let NonEmpty/singleton =
missing sha256:c9197aabe97695f7ca66f7419bf172d806b2c915594a8fc0d2ff6495db496ff2
? ../NonEmpty/singleton.dhall

let List/uncons
: ∀(a : Type) → List a → Optional (NonEmpty a)
= {- This version uses the `ls` argument only once to prevent cache blowups at the price
of performing two passes over the list:
A first one to reverse it, a second one with `List/fold` to determine
the head element.
See https://github.com/dhall-lang/dhall-lang/pull/1015#issuecomment-633381024
for some context regarding the caching issue.
-}
λ(a : Type) →
λ(ls : List a) →
List/fold
a
(List/reverse a ls)
(Optional (NonEmpty a))
( λ(x : a) →
λ(acc : Optional (NonEmpty a)) →
merge
{ None = Some (NonEmpty/singleton a x)
, Some =
λ(ne : NonEmpty a) → Some (ne ⫽ { tail = ne.tail # [ x ] })
}
acc
)
(None (NonEmpty a))

let NonEmpty/mapHead
: ∀(a : Type) → (a → a) → NonEmpty a → NonEmpty a
= λ(a : Type) →
λ(fn : aa) →
λ(ls : NonEmpty a) →
ls ⫽ { head = fn ls.head }

let NonEmpty/mapTail
: ∀(a : Type) → (a → a) → NonEmpty a → NonEmpty a
= λ(a : Type) →
λ(fn : aa) →
λ(ls : NonEmpty a) →
ls ⫽ { tail = List/map a a fn ls.tail }

let NonEmpty/prepend
: ∀(a : Type) → a → NonEmpty a → NonEmpty a
= λ(a : Type) →
λ(prefix : a) →
λ(ls : NonEmpty a) →
{ head = prefix, tail = NonEmpty/toList a ls }

let NonYtpme
: Type → Type
= λ(a : Type) → { init : List a, last : a }

let List/unsnoc
: ∀(a : Type) → List a → Optional (NonYtpme a)
= λ(a : Type) →
λ(ls : List a) →
List/fold
a
ls
(Optional (NonYtpme a))
( λ(x : a) →
λ(acc : Optional (NonYtpme a)) →
merge
{ None = Some { init = [] : List a, last = x }
, Some =
λ(ny : NonYtpme a) → Some (ny ⫽ { init = [ x ] # ny.init })
}
acc
)
(None (NonYtpme a))

let NonEmpty/mapLast
: ∀(a : Type) → (a → a) → NonEmpty a → NonEmpty a
= λ(a : Type) →
λ(fn : aa) →
λ(ls : NonEmpty a) →
merge
{ Some = λ(x : NonYtpme a) → ls ⫽ { tail = x.init # [ fn x.last ] }
, None = NonEmpty/singleton a (fn ls.head)
}
(List/unsnoc a ls.tail)

let NonEmpty/mapLeading
: ∀(a : Type) → (a → a) → NonEmpty a → NonEmpty a
= λ(a : Type) →
λ(fn : aa) →
λ(ls : NonEmpty a) →
merge
{ Some =
λ(x : NonYtpme a) →
{ head = fn ls.head
, tail = List/map a a fn x.init # [ x.last ]
}
, None = ls
}
(List/unsnoc a ls.tail)

let Lines
: Type
= NonEmpty Text

let Block
: Type
= < Simple : Text | Complex : Lines >

let Block/toLines
: BlockLines
= λ(block : Block) →
merge
{ Simple = NonEmpty/singleton Text
, Complex = Function/identity Lines
}
block

let manyBlocks
: ∀(a : Type) → Text → (NonEmpty a → Lines) → List a → Block
= λ(a : Type) →
λ(ifEmpty : Text) →
λ(render : NonEmpty aLines) →
λ(inputs : List a) →
merge
{ Some = λ(inputs : NonEmpty a) → Block.Complex (render inputs)
, None = Block.Simple ifEmpty
}
(List/uncons a inputs)

let blockToText
: Block → Text
= λ(block : Block) →
Text/concatMap
Text
(λ(line : Text) → line ++ "\n")
(NonEmpty/toList Text (Block/toLines block))

let addPrefix = λ(prefix : Text) → λ(line : Text) → prefix ++ line

let addIndent = addPrefix " "

let indentTail = NonEmpty/mapTail Text addIndent

let Format =
missing sha256:d7936b510cfc091faa994652af0eb5feb889cd44bc989edbe4f1eb8c5623caac
? ./Format.dhall

let ObjectField = { mapKey : Text, mapValue : Block }

let -- Essentially the same thing as `Text/show`, except that this does not
-- escape `$`
escape =
List/fold
(Text → Text)
[ Text/replace "\"" "\\\""
, Text/replace "\b" "\\b"
, Text/replace "\f" "\\f"
, Text/replace "\n" "\\n"
, Text/replace "\r" "\\r"
, Text/replace "\t" "\\t"
, Text/replace "\\" "\\\\"
]
Text
(λ(replace : Text → Text) → λ(text : Text) → replace text)

let renderJSONStruct =
λ(prefix : Text) →
λ(suffix : Text) →
λ(blocks : NonEmpty Lines) →
let indent = List/map Text Text addIndent

let appendComma
: LinesLines
= NonEmpty/mapLast Text (λ(line : Text) → line ++ ",")

let blocks = NonEmpty/mapLeading Lines appendComma blocks

let block = NonEmpty/concat Text blocks

in merge
{ None =
NonEmpty/singleton Text "${prefix} ${block.head} ${suffix}"
, Some =
λ(ny : NonYtpme Text) →
{ head = prefix
, tail =
indent ([ block.head ] # ny.init # [ ny.last ])
# [ suffix ]
}
}
(List/unsnoc Text block.tail)

let renderObject =
λ(format : Format) →
λ(fields : NonEmpty ObjectField) →
let keystr = λ(field : ObjectField) → "\"${escape field.mapKey}\":"

let prefixKeyOnFirst =
λ(field : ObjectField) →
NonEmpty/mapHead
Text
(addPrefix "${keystr field} ")
(Block/toLines field.mapValue)

let prependKeyLine =
λ(field : ObjectField) →
NonEmpty/prepend
Text
(keystr field)
(Block/toLines field.mapValue)

let renderYAMLField =
λ(field : ObjectField) →
merge
{ Simple =
λ(line : Text) →
NonEmpty/singleton Text "${keystr field} ${line}"
, Complex = λ(_ : Lines) → indentTail (prependKeyLine field)
}
field.mapValue

in merge
{ JSON =
renderJSONStruct
"{"
"}"
(NonEmpty/map ObjectField Lines prefixKeyOnFirst fields)
, YAML =
NonEmpty/concat
Text
(NonEmpty/map ObjectField Lines renderYAMLField fields)
}
format

let renderYAMLArrayField =
λ(block : Block) →
NonEmpty/mapHead
Text
(addPrefix "- ")
(indentTail (Block/toLines block))

let renderArray =
λ(format : Format) →
λ(fields : NonEmpty Block) →
merge
{ JSON =
renderJSONStruct
"["
"]"
(NonEmpty/map Block Lines Block/toLines fields)
, YAML =
NonEmpty/concat
Text
(NonEmpty/map Block Lines renderYAMLArrayField fields)
}
format

let renderAs
: FormatJSON.Type → Text
= λ(format : Format) →
λ(json : JSON.Type) →
blockToText
( json
Block
{ string = λ(x : Text) → Block.Simple "\"${escape x}\""
, double = λ(x : Double) → Block.Simple (Double/show x)
, integer = λ(x : Integer) → Block.Simple (JSON.renderInteger x)
, object = manyBlocks ObjectField "{}" (renderObject format)
, array = manyBlocks Block "[]" (renderArray format)
, bool =
λ(x : Bool) → Block.Simple (if x then "true" else "false")
, null = Block.Simple "null"
}
)

let example0 =
let data =
JSON.array
[ JSON.bool True
, JSON.string "Hello"
, JSON.object
[ { mapKey = "foo", mapValue = JSON.null }
, { mapKey = "bar", mapValue = JSON.double 1.0 }
]
]

let yaml =
assert
: renderAs Format.YAML data
≡ ''
- true
- "Hello"
- "foo": null
"bar": 1.0
''

let json =
assert
: renderAs Format.JSON data
≡ ''
[
true,
"Hello",
{
"foo": null,
"bar": 1.0
}
]
''

in True

let example1 =
let data =
JSON.object
[ { mapKey = "zero", mapValue = JSON.array ([] : List JSON.Type) }
, { mapKey = "one", mapValue = JSON.array [ JSON.string "a" ] }
, { mapKey = "two"
, mapValue = JSON.array [ JSON.string "a", JSON.string "b" ]
}
]

let yaml =
assert
: renderAs Format.YAML data
≡ ''
"zero": []
"one":
- "a"
"two":
- "a"
- "b"
''

let json =
assert
: renderAs Format.JSON data
≡ ''
{
"zero": [],
"one": [ "a" ],
"two": [
"a",
"b"
]
}
''

in True

let example2 =
let data =
JSON.object
[ { mapKey = "zero"
, mapValue =
JSON.object
(toMap {=} : List { mapKey : Text, mapValue : JSON.Type })
}
, { mapKey = "one"
, mapValue = JSON.object (toMap { a = JSON.null })
}
, { mapKey = "two"
, mapValue =
JSON.object (toMap { a = JSON.null, b = JSON.null })
}
]

let yaml =
assert
: renderAs Format.YAML data
≡ ''
"zero": {}
"one":
"a": null
"two":
"a": null
"b": null
''

let json =
assert
: renderAs Format.JSON data
≡ ''
{
"zero": {},
"one": { "a": null },
"two": {
"a": null,
"b": null
}
}
''

in True

let example3 =
let specialCharacters =
''
"\${"\b\f"}
${"\r"} $''

let data =
JSON.object
[ { mapKey = specialCharacters
, mapValue = JSON.string specialCharacters
}
]

in assert
: renderAs Format.JSON data
≡ ''
{ "\"\\\b\f\n\r\t$": "\"\\\b\f\n\r\t$" }
''

in renderAs