private bool ApplyArgument(string arg, ICommand command, CommandDescriptor commandDescriptor)
{
// Determine the name of the argument
Prefix prefix;
int endIndex;
string argName;
if (arg.StartsWith("--"))
{
prefix = Prefix.DoubleDash;
endIndex = arg.IndexOfAny(KeyValueSeparators, 2);
argName = arg.Substring(2, endIndex == -1 ? arg.Length - 2 : endIndex - 2);
}
else if (arg.StartsWith("-"))
{
prefix = Prefix.Dash;
endIndex = arg.IndexOfAny(KeyValueSeparators, 1);
argName = arg.Substring(1, endIndex == -1 ? arg.Length - 1 : endIndex - 1);
}
else if (arg.StartsWith("/"))
{
prefix = Prefix.ForwardSlash;
endIndex = arg.IndexOfAny(KeyValueSeparators, 1);
argName = arg.Substring(1, endIndex == -1 ? arg.Length - 1 : endIndex - 1);
}
else
{
// If the argument does not start a with the start of a named argument, we don't have any changes to make
return(false);
}
// Remove the value suffixes from the argument name (these cannot be separators because args can have a dash in their name)
argName = argName.TrimEnd(ValueSuffixes);
// Attempt to find a descriptor for this argument
List <ArgumentDescriptor> descriptors = new List <ArgumentDescriptor>();
if (prefix == Prefix.DoubleDash || prefix == Prefix.ForwardSlash)
{
descriptors.AddRange(commandDescriptor.Arguments.Where(a => a.LongNames.Contains(argName)));
}
if (prefix == Prefix.Dash || prefix == Prefix.ForwardSlash)
{
descriptors.AddRange(commandDescriptor.Arguments.Where(a => a.ShortNames.Contains(argName)));
}
if (descriptors.Count == 0)
{
throw new Exception(string.Format("Unknown argument '{0}'.", arg));
}
if (descriptors.Count > 1)
{
throw new Exception(string.Format("Ambiguous argument '{0}', found {1} descriptors.", arg, descriptors.Count));
}
var descriptor = descriptors[0];
// Get current value of this argument
object currentValue = descriptor.PropertyInfo.GetValue(command, null);
// Determine the value of the argument
object argValue;
if (ValueSuffixes.Contains(arg[arg.Length - 1]))
{
// Parse value with the '+' or '-'
argValue = ValueConverter.ParseValue(descriptor.ArgumentType, arg[arg.Length - 1].ToString(), currentValue);
}
else if (endIndex == -1)
{
// No value was specified, so it is most likely a flag
argValue = ValueConverter.ParseValue(descriptor.ArgumentType, null, currentValue);
}
else
{
// Parse value without the ':'
argValue = ValueConverter.ParseValue(descriptor.ArgumentType, arg.Substring(endIndex + 1), currentValue);
}
// Set the value of the argument
descriptor.PropertyInfo.SetValue(command, argValue, null);
// We have processed this argument, so indicate this
return(true);
}