internal RequisiteAnnotation Parse(List<Token> tokens)
{
if (tokens == null)
{
throw new ArgumentNullException(nameof(tokens));
}
if (tokens.Count == 0)
{
throw new ArgumentException("tokens can't be empty");
}
RequisiteAnnotation annotation = new RequisiteAnnotation
{
IsNegation = false,
Attribute = string.Empty,
Trait = string.Empty,
Level = null
};
ParseExpression(tokens, ref annotation);
if (tokens.Count > 0)
{
throw new ArgumentException($"Extra tokens at the end of the expression. Next extra token is {tokens[0]}");
}
return annotation;
}
private void ParseExpression(List<Token> tokens, ref RequisiteAnnotation annotation)
{
Token current = tokens[0];
switch (current.TokenType)
{
case TokenType.Negation:
annotation.IsNegation = true;
tokens.RemoveAt(0);
ParsePositiveExpression(tokens, ref annotation);
break;
case TokenType.Number:
throw new ArgumentException($"Invalid token {current} found. Expected token types were: {nameof(TokenType.Negation)}, {nameof(TokenType.Attribute)}, {nameof(TokenType.Trait)}");
default:
ParsePositiveExpression(tokens, ref annotation);
break;
}
}
private void ParseNumber(List<Token> tokens, ref RequisiteAnnotation annotation)
{
if (tokens.Count == 0)
{
return;
}
Token current = tokens[0];
switch (current.TokenType)
{
case TokenType.Number:
annotation.Level = int.Parse(current.Text);
tokens.RemoveAt(0);
break;
default:
throw new ArgumentException($"Invalid token {current} found. Expected token types were: {nameof(TokenType.Number)}");
}
}
public static Requisite FromRequisiteAnnotation(RequisiteAnnotation annotation)
{
return Requisite.Default.Value;
}
