Handlebar values

undefined =
    BoolenValue False


null =
    BooleanValue False


int =
    StringValue (String.fromInt int)


float =
    StringValue (String.fromFloat float)

Get a value by the path.

Use @key to get the key of a value.

import Dict


object : Value
object = Dict.fromList [ ( "name", StringValue "Jack" ) ] |> ObjectValue


object
    |> get [ "name" ]
    --> Just (StringValue "Jack")


object
    |> get [ "name", "@key" ]
    --> Just (StringValue "name")


[ ( "name"
  , [ ( "@key", StringValue "impossible State" ) ] |> Dict.fromList |> ObjectValue
  )
]
    |> Dict.fromList
    |> ObjectValue
    |> get [ "name", "@key" ]
    --> Just (StringValue "name")


object
    |> get [ "@key" ]
    --> Nothing


object
    |> get []
    --> Just object

Use @index to get the index

import Array


jack : Value
jack = StringValue "Jack"


gill : Value
gill = StringValue "Gill"


array : Value
array =
    [ jack, gill ]
    |> Array.fromList
    |> ArrayValue


array
    |> get []
    --> Just array


array
    |> get ["0"]
    --> Just jack


array
    |> get ["0","@index"]
    --> Just (StringValue "0")


array
    |> get ["0","@first"]
    --> Just (BooleanValue True)


array
    |> get ["0","@last"]
    --> Just (BooleanValue False)


array
    |> get ["1"]
    --> Just gill


array
    |> get ["1","@index"]
    --> Just (StringValue "1")


array
    |> get ["1","@last"]
    --> Just (BooleanValue True)


array
    |> get ["0","@last"]
    --> Just (BooleanValue False)


array
    |> get ["-1"]
    --> Nothing


Array.empty
    |> ArrayValue
    |> get ["0"]
    --> Nothing


Array.empty
    |> ArrayValue
    |> get ["0","@index"]
    --> Nothing


Array.empty
    |> ArrayValue
    |> get ["0","@first"]
    --> Nothing


Array.empty
    |> ArrayValue
    |> get ["0","@last"]
    --> Nothing

For Strings and Boolean only an empty path is allowed.

jack
    |> get ["something"]
    --> Nothing


jack
    |> get []
    --> Just jack


isValid : Value
isValid =
    BooleanValue True


isValid
    |> get ["something"]
    --> Nothing


isValid
    |> get []
    --> Just isValid

convert Json into Handlebar values