/// <summary>
/// Returns attribute argument at the specified <paramref name="position"/> and with the given <paramref name="argumentName"/>.
/// <para>If <paramref name="argumentName"/> is <see langword="null"/>, only <paramref name="position"/> is included in the search.</para>
/// <para>If no appropriate argument found, returns <see langword="null"/>.</para>
/// </summary>
/// <param name="attribute"><see cref="AttributeSyntax"/> to get the argument of.</param>
/// <param name="position">Position of argument to get.</param>
/// <param name="argumentName">Name of the argument to get the location of.</param>
/// <exception cref="ArgumentNullException"><paramref name="attribute"/> is <see langword="null"/>.</exception>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="position"/> cannot be less than <c>0</c>.</exception>
public static AttributeArgumentSyntax?GetArgument(this AttributeSyntax attribute, int position, string?argumentName = null)
{
if (attribute is null)
{
throw new ArgumentNullException(nameof(attribute));
}
if (position < 0)
{
throw new ArgumentOutOfRangeException(nameof(position), "Argument position cannot be less than 0!");
}
if (attribute.ArgumentList is null)
{
return(null);
}
SeparatedSyntaxList <AttributeArgumentSyntax> arguments = attribute.ArgumentList.Arguments;
if (!arguments.Any())
{
return(null);
}
if (string.IsNullOrWhiteSpace(argumentName))
{
if (position >= arguments.Count)
{
return(null);
}
return(arguments[position]);
}
if (position < arguments.Count)
{
AttributeArgumentSyntax arg = arguments[position];
if (arg.GetName() == argumentName)
{
return(arg);
}
}
return(arguments.FirstOrDefault(arg => arg.GetName() == argumentName));
}
