private TokenParseResult TryParseNamedArgument(string argument, string argumentPrefix, NamedArgumentType namedArgType, out IReadOnlyList <ArgumentAndValue> parsedArgs)
{
var prefixLength = argumentPrefix.Length;
Debug.Assert(argument.Length >= prefixLength);
// Figure out where the argument name ends.
var endIndex = argument.IndexOfAny(_argumentSet.Attribute.ArgumentValueSeparators, prefixLength);
// Special case: check for '+' and '-' for booleans.
if (endIndex < 0 && argument.Length >= 2)
{
var lastArgumentChar = argument[argument.Length - 1];
if (ArgumentNameTerminators.Any(t => lastArgumentChar.Equals(t)))
{
endIndex = argument.Length - 1;
}
}
// If we don't have a separator or terminator, then consume the full string.
if (endIndex < 0)
{
endIndex = argument.Length;
}
// Extract the argument name(s), separate from the prefix
// or optional argument value.
var options = argument.Substring(prefixLength, endIndex - prefixLength);
// Extract the option argument (a.k.a. value), if there is one.
string optionArgument = null;
if (argument.Length > prefixLength + options.Length)
{
// If there's an argument value separator, then extract the value after the separator.
if (_argumentSet.Attribute.ArgumentValueSeparators.Any(sep => argument[prefixLength + options.Length] == sep))
{
optionArgument = argument.Substring(prefixLength + options.Length + 1);
}
// Otherwise, it might be a terminator; extract the rest of the string.
else
{
optionArgument = argument.Substring(prefixLength + options.Length);
}
}
// Now try to figure out how many names are present.
if (namedArgType == NamedArgumentType.ShortName &&
(_argumentSet.Attribute.AllowMultipleShortNamesInOneToken || _argumentSet.Attribute.AllowElidingSeparatorAfterShortName))
{
Debug.Assert(_argumentSet.Attribute.ShortNamesAreOneCharacterLong);
// Since short names are one character long, we parse them one at a
// time, preparing for multiple arguments in this one token.
var args = new List <ArgumentAndValue>();
for (var index = 0; index < options.Length; ++index)
{
// Try parsing it as a short name; bail immediately if we find an invalid
// one.
var possibleShortName = new string(options[index], 1);
if (!_argumentSet.TryGetNamedArgument(possibleShortName, out ArgumentDefinition arg))
{
parsedArgs = null;
return(TokenParseResult.UnknownNamedArgument(namedArgType, possibleShortName));
}
// If this parsed as a short name that takes a required option argument,
// and we didn't see an option argument, and we allow mushing together
// short names and their option arguments, then try parsing the rest of
// this token as an option argument.
var lastChar = index == options.Length - 1;
if (arg.RequiresOptionArgument &&
_argumentSet.Attribute.AllowElidingSeparatorAfterShortName &&
optionArgument == null &&
!lastChar)
{
optionArgument = options.Substring(index + 1);
index = options.Length - 1;
lastChar = true;
}
if (!_argumentSet.Attribute.AllowMultipleShortNamesInOneToken &&
args.Count > 0)
{
parsedArgs = null;
return(TokenParseResult.UnknownNamedArgument());
}
args.Add(new ArgumentAndValue
{
Arg = arg,
Value = lastChar ? optionArgument : null
});
}
parsedArgs = args;
}
else
{
// Try to look up the argument by name.
if (!_argumentSet.TryGetNamedArgument(options, out ArgumentDefinition arg))
{
parsedArgs = null;
return(TokenParseResult.UnknownNamedArgument(namedArgType, options));
}
parsedArgs = new[] { new ArgumentAndValue
{
Arg = arg,
Value = optionArgument
} };
}
// If the last named argument we saw in this token required an
// option argument to go with it, then yield that information
// so it can be used by the caller (e.g. in completion generation).
var lastArg = parsedArgs.GetLastOrDefault();
if (lastArg != null &&
lastArg.Arg.RequiresOptionArgument &&
string.IsNullOrEmpty(lastArg.Value))
{
return(TokenParseResult.RequiresOptionArgument(lastArg.Arg));
}
return(TokenParseResult.Ready);
}
private TokenParseResult TryParseNextNamedArgument(IReadOnlyList <string> args, int index, string longNameArgumentPrefix, string shortNameArgumentPrefix, object destination, out int argsConsumed)
{
argsConsumed = 1;
var argument = args[index];
var result = TokenParseResult.UnknownNamedArgument();
IReadOnlyList <ArgumentAndValue> parsedArgs = null;
if (result.IsUnknown && longNameArgumentPrefix != null)
{
result = TryParseNamedArgument(argument, longNameArgumentPrefix, NamedArgumentType.LongName, out parsedArgs);
}
if (result.IsUnknown && shortNameArgumentPrefix != null)
{
result = TryParseNamedArgument(argument, shortNameArgumentPrefix, NamedArgumentType.ShortName, out parsedArgs);
}
// If our policy allows a named argument's value to be placed
// in the following token, and if we're missing a required
// value, and if there's at least one more token, then try
// to parse the next token as the current argument's value.
if (result.State == TokenParseResultState.RequiresOptionArgument &&
_argumentSet.Attribute.AllowNamedArgumentValueAsSucceedingToken &&
index + 1 < args.Count)
{
var lastParsedArg = parsedArgs.GetLast();
Debug.Assert(lastParsedArg.Arg.RequiresOptionArgument);
Debug.Assert(!lastParsedArg.Arg.TakesRestOfLine);
Debug.Assert(string.IsNullOrEmpty(parsedArgs.GetLast().Value));
++index;
++argsConsumed;
lastParsedArg.Value = args[index];
result = TokenParseResult.Ready;
}
if (!result.IsReady)
{
ReportUnrecognizedArgument(result, argument);
return(result);
}
foreach (var parsedArg in parsedArgs)
{
// TODO: Obviate the need to use string.Empty here.
var argValue = parsedArg.Value ?? string.Empty;
if (parsedArg.Arg.TakesRestOfLine)
{
if (!parsedArg.Arg.TrySetRestOfLine(argValue, args.Skip(index + 1), destination))
{
result = TokenParseResult.FailedParsing;
continue;
}
argsConsumed = args.Count - index; // skip the rest of the line
}
else
{
if (!TryParseAndStore(parsedArg.Arg, argValue, destination))
{
result = TokenParseResult.FailedParsing;
continue;
}
}
}
return(result);
}
