/// Delay parsing to type-specific function
/// @access private
/// according to found character
/// @param {String} $source - JSON complete source
/// @param {Number} $pointer - current pointer
/// @throw Unexpected token $token.
/// @throw Empty JSON string.
/// @return {List} - (new pointer, parsed value)
/// @require {function} _throw
/// @require {function} _json-decode--map
/// @require {function} _json-decode--list
/// @require {function} _json-decode--true
/// @require {function} _json-decode--false
/// @require {function} _json-decode--string
/// @require {function} _json-decode--null
/// @require {function} _json-decode--number
@function _json-decode--value($source, $pointer) {
  $length: str-length($source);

  @while $pointer <= $length {
    $token: str-slice($source, $pointer, $pointer);
    $pointer: $pointer + 1;

    @if $token == '{' {
      @return _json-decode--map($source, $pointer);
    } @else if $token == '[' {
      @return _json-decode--list($source, $pointer);
    } @else if $token == 't' {
      @return _json-decode--true($source, $pointer);
    } @else if $token == 'f' {
      @return _json-decode--false($source, $pointer);
    } @else if $token == '"' {
      @return _json-decode--string($source, $pointer);
    } @else if $token == 'n' {
      @return _json-decode--null($source, $pointer);
    } @else if index('1' '2' '3' '4' '5' '6' '7' '8' '9' '0' '-' '.', $token) {
      @return _json-decode--number($source, $pointer);
    } @else if $token == ' ' or $token == "	" {
      // @continue;
    } @else {
      @return _throw("Unexpected token `#{$token}`.", $pointer);
    }
  }

  @return _throw("Empty JSON string.", $pointer);
}