private static (OptionRef?, IEnumerable <string>) ParseShortOptionRef(IReadOnlyList <string> input)
{
var match = _shortNamePattern.Match(input[0]);
if (!match.Success)
{
return(null, input);
}
var optionName = OptionName.Parse(match.Groups["name"].Value);
if (optionName == null)
{
// TODO: Create LogicErrorException
throw new Exception("LOGIC ERROR: option name in option ref regex is not a valid option name");
}
if (match.Groups["next"].Success)
{
var next = match.Groups["next"].Value;
var optionRef = new OptionRef(optionName, next, JoinType.Adjoined);
return(optionRef, input.Skip(1));
}
if (input.Count > 1)
{
var next = input[1];
var optionRef = new OptionRef(optionName, next, JoinType.Space);
return(optionRef, input.Skip(2));
}
return(new OptionRef(optionName, null), input.Skip(1));
}
public (IEnumerable <Action <TOptions> >, IEnumerable <string>) Parse(IEnumerable <string> input)
{
var tokens = input?.ToList() ?? throw new ArgumentNullException(nameof(input));
var assignments = new List <Action <TOptions> >();
var arguments = new List <string>();
while (tokens.Count > 0)
{
// TODO: Encapsulate context and refactor
(var optionRef, var newInput) = OptionRef.Parse(tokens);
if (optionRef == null)
{
(tokens, arguments) = ConsumeArguments(tokens, arguments);
continue;
}
var optionName = optionRef.OptionName;
var option = optionName switch
{
OptionName.Short s => _options.FirstOrDefault(o => o.ShortName == s),
OptionName.Long l => _options.FirstOrDefault(o => o.LongName == l),
OptionName n => throw new LogicErrorException($"unknown {nameof(OptionName)} subtype '{n.GetType().Name}'"),
};
// TODO: Treat these as arguments? Probably just have to put them after "--"
// TODO: Better error communication.
if (option == null)
{
throw new Exception($"Unknown option '{optionName}'");
}
// TODO: Express this better :/
// An explicit value can only be assigned to an option with long-name/equals, default is "true"
var value = option.IsFlag && optionRef.Join != OptionRef.JoinType.Equals
? "true"
: optionRef.NextToken;
// TODO: Better error communication.
if (value == null)
{
throw new Exception($"Missing required argument for option '{optionName}'");
}
assignments.Add(option.Parse(value));
tokens = newInput.ToList();
// Flags can only have values joined by '='. If a flag has a next token that wasn't joined by '=' then
// the token needs to go back into the input.
if (optionRef.NextToken != null && option.IsFlag && optionRef.Join != OptionRef.JoinType.Equals)
{
// If the token was adjoined then the value is a sequence of short options and needs a leading '-'.
var token = optionRef.Join == OptionRef.JoinType.Adjoined
? $"-{optionRef.NextToken}"
: optionRef.NextToken;
tokens.Insert(0, token);
}
}
return(assignments, arguments);
}