public static string AsString(this TokenSpan span, string source)
{
var sb = new StringBuilder(span.Size);
var reader = new CharReader(source, span.Left, span.Size);
switch (span.Token)
{
case Token.String:
reader.MoveNext();
while (reader.MoveNext() && reader.Current != '\'')
{
sb.Append(reader.Current);
}
break;
default:
//should use reader here as above!!!
//!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
return(source.Substring(span.Left, span.Right - span.Left));
}
return(sb.ToString());
}
public TokenSpan Emit(Token type)
{
var token = TokenSpan.Of(type, Left, Right);
Left = Right;
return(token);
}
public static int AsInt(this TokenSpan span, string source)
{
span.Token.MustBe(Token.Number);
var reader = new CharReader(source, span.Left, span.Size);
int acc = 0;
while (reader.MoveNext())
{
acc *= 10;
acc += reader.Current.DecodeAsDecimal();
}
return(acc);
}
public static bool Match(this TokenSpan span, string from, string comp) => string.Compare(from, span.Left, comp, 0, span.Right - span.Left) == 0;