module Parsers.Json (json, nil, number, bool, string, array, object) where

import Parser              (Parser)
import ParserCombinators   (IsMatch (..), maybeWithin, (<|>), (|*))
import Parsers.Char        (colon, doubleQuote)
import Parsers.Collections (listOf, mapOf)
import Parsers.Number      (double)
import Parsers.String      (spacing, withinDoubleQuotes)
import SyntaxTrees.Json    (JsExpression (..))


json :: Parser JsExpression
json = maybeWithin spacing jsValue where

  jsValue = element <|> container


nil :: Parser JsExpression
nil = JsNull <$ is "null"

number :: Parser JsExpression
number = JsNumber <$> double


bool :: Parser JsExpression
bool = JsBool <$> (True  <$ is "true" <|>
                   False <$ is "false")


string :: Parser JsExpression
string = JsString <$> text


array :: Parser JsExpression
array = JsArray <$> listOf json


object :: Parser JsExpression
object = JsObject <$> mapOf colon text json



element :: Parser JsExpression
element = number <|> bool <|> nil <|> string

container :: Parser JsExpression
container = array <|> object




text :: Parser String
text = withinDoubleQuotes (inverse doubleQuote |*)