private static StringSegment ParseJsConditionalExpression(this StringSegment literal, JsToken test, out JsConditionalExpression expression)
{
literal = literal.Advance(1);
literal = literal.ParseJsExpression(out var consequent);
literal = literal.AdvancePastWhitespace();
if (!literal.FirstCharEquals(':'))
{
throw new SyntaxErrorException($"Expected Conditional ':' but was {literal.DebugFirstChar()}");
}
literal = literal.Advance(1);
literal = literal.ParseJsExpression(out var alternate);
expression = new JsConditionalExpression(test, consequent, alternate);
return(literal);
}