/// <summary>
/// Quads where <see cref="Quad.Object"/> is
/// <see cref="Text"/> with specified language.
/// </summary>
public static IEnumerable <Quad> IsTypeTextLang(
this IEnumerable <Quad> self,
IBasicNodeFactory f,
params string[] language)
{
var nodes = language.Select(x => f.Text("", x));
return(self.Where(x =>
x.Object is Node <Text> txt &&
nodes.Any(v => v.Value.Language == txt.Value.Language)));
}
/// <summary>
/// Creates either a text node or literal node.
/// </summary>
public static Node TextOrLiteral(this IBasicNodeFactory self,
ReadOnlySpan <char> value, ReadOnlySpan <char> language)
=> language.IsEmpty ? (Node)self.New(new string(value))
: self.Text(value, language);