protected override Variable Evaluate(ParsingScript script)
{
script.MoveForwardIf(Constants.SPACE);
if (!script.FromPrev(Constants.RETURN.Length).Contains(Constants.RETURN))
{
script.Backward();
}
Variable result = Utils.GetItem(script);
// If we are in Return, we are done:
script.SetDone();
result.IsReturn = true;
return(result);
}
static bool StillCollecting(string item, char[] to, ParsingScript script,
ref string action)
{
char prev = script.TryPrevPrev();
char ch = script.TryPrev();
char next = script.TryCurrent();
if (to.Contains(ch) || ch == Constants.START_ARG ||
ch == Constants.START_GROUP ||
next == Constants.EMPTY)
{
return(false);
}
// Case of a negative number, or a pointer, or starting with the closing bracket:
if (item.Length == 0 &&
((ch == '-' && next != '-') || ch == '&' ||
ch == Constants.END_ARRAY ||
ch == Constants.END_ARG))
{
return(true);
}
// Case of a scientific notation 1.2e+5 or 1.2e-5 or 1e5:
if (Char.ToUpper(prev) == 'E' &&
(ch == '-' || ch == '+' || Char.IsDigit(ch)) &&
item.Length > 1 && Char.IsDigit(item[item.Length - 2]))
{
return(true);
}
// Otherwise if it's an action (+, -, *, etc.) or a space
// we're done collecting current token.
if ((action = Utils.ValidAction(script.FromPrev())) != null ||
(item.Length > 0 && ch == Constants.SPACE))
{
return(false);
}
if (ch == Constants.TERNARY_OPERATOR)
{
script.Backward();
return(false);
}
return(true);
}
public static string GetToken(ParsingScript script, char [] to)
{
char curr = script.TryCurrent();
char prev = script.TryPrev();
if (!to.Contains(Constants.SPACE))
{
// Skip a leading space unless we are inside of quotes
while (curr == Constants.SPACE && prev != Constants.QUOTE)
{
script.Forward();
curr = script.TryCurrent();
prev = script.TryPrev();
}
}
// String in quotes
bool inQuotes = curr == Constants.QUOTE;
if (inQuotes)
{
int qend = script.Find(Constants.QUOTE, script.Pointer + 1);
if (qend == -1)
{
throw new ArgumentException("Unmatched quotes in [" +
script.FromPrev() + "]");
}
string result = script.Substr(script.Pointer + 1, qend - script.Pointer - 1);
script.Pointer = qend + 1;
return(result);
}
script.MoveForwardIf(Constants.QUOTE);
int end = script.FindFirstOf(to);
end = end < 0 ? script.Size() : end;
// Skip found characters that have a backslash before.
while (end > 0 && end + 1 < script.Size() &&
script.String [end - 1] == '\\')
{
end = script.FindFirstOf(to, end + 1);
}
end = end < 0 ? script.Size() : end;
if (script.At(end - 1) == Constants.QUOTE)
{
end--;
}
string var = script.Substr(script.Pointer, end - script.Pointer);
// \"yes\" --> "yes"
var = var.Replace("\\\"", "\"");
script.Pointer = end;
script.MoveForwardIf(Constants.QUOTE, Constants.SPACE);
return(var);
}