elm/libraries/Json.elm

76 lines
1.7 KiB
Elm

module Json where
import Dict
import JavaScript as JS
import Native.Json as Native
data Value
= String String
| Number Float
| Boolean Bool
| Null
| Array [Value]
| Object (Dict String Value)
-- String Converters
toString : Value -> String
toString v = JS.toString (Native.toPrettyJSString "" v)
toPrettyString : String -> Value -> String
toPrettyString sep v = JS.toString (Native.toPrettyJSString sep v)
toJSString : Value -> JSString
toJSString v = Native.toPrettyJSString "" v
fromString : String -> Maybe Value
fromString s = Native.fromJSString (JS.fromString s)
fromJSString : JSString -> Maybe Value
fromJSString = Native.fromJSString
-- Extract Elm values from Json values
string : String -> Value -> String
string base v = case v of { String s -> s ; _ -> base }
number : Float -> Value -> Float
number base v = case v of { Number n -> n ; _ -> base }
boolean : Bool -> Value -> Bool
boolean base v = case v of { Boolean b -> b ; _ -> base }
array : [Value] -> Value -> [Value]
array base v = case v of { Array a -> a ; _ -> base }
object : Dict String Value -> Value -> Dict String Value
object base v = case v of { Object o -> o ; _ -> base }
-- Extract Elm values from dictionaries of Json values
find get =
let f base key dict =
case Dict.lookup key dict of
Nothing -> base
Just v -> get base v
in f
findString : String -> Dict String Value -> String
findString = find string
findNumber : Float -> Dict String Value -> Float
findNumber = find number
findBoolean : Bool -> Dict String Value -> Bool
findBoolean = find boolean
findArray : [Value] -> Dict String Value -> [Value]
findArray = find array
findObject : Dict String Value -> Dict String Value -> Dict String Value
findObject = find object