private static ParseResult <OptionNode> ParseOption(ICharInput input)
{
var startPos = input.Position;
if (!IsOptionPrefix(input.Current))
{
throw new ParsingException("invalid option prefix '{0}'");
}
input = input.GetNext();
var name =
input.ConsumeWhile(
c =>
c != CharInput.EOF &&
!char.IsWhiteSpace(c) &&
c != '=' &&
c != '+' &&
c != '-');
if (name.Result.Length == 0)
{
throw new ParsingException("option name expected", input.Position);
}
var nextChar = name.InputRest.Current;
if (nextChar == '+' || nextChar == '-')
{
return
(CreateResult(
new OptionNode(name.Result, startPos, name.InputRest.Position - startPos + 1, nextChar == '+'),
name.InputRest.GetNext()));
}
if (nextChar == '=')
{
var value = ParseQuotedOrNonquotedValue(name.InputRest.GetNext());
if (value.Result.Text.Length == 0)
{
throw new ParsingException(
"option '{0}' value not specified".FormatWith(name.Result),
value.Result.Position);
}
return
(new ParseResult <OptionNode>(
new OptionNode(name.Result, startPos, value.InputRest.Position - startPos, value.Result),
value.InputRest));
}
return
(CreateResult(
new OptionNode(name.Result, startPos, name.InputRest.Position - startPos),
name.InputRest));
}
private static ParseResult <QuotedOrNonquotedValueNode> ParseQuotedValue(ICharInput input)
{
var startPos = input.Position;
input = input.ConsumeChar(_quota);
var res = input.ConsumeWhile(_quota);
input = res.InputRest.ConsumeChar(_quota);
return
(CreateResult(
new QuotedOrNonquotedValueNode(res.Result, startPos, input.Position - startPos, true),
input));
}