private static bool TryTakeDateTime(StringKeeper stringKeeper, out StringKeeper newStringKeeper, out Token token)
{
if (stringKeeper.IsNext("datetime'"))
{
var work = stringKeeper.Take(8);
Debug.Assert(work.Next == '\'');
StringKeeper literalEnd;
Token literalToken;
TryTakeStringLiteral(work, out literalEnd, out literalToken);
newStringKeeper = literalEnd;
if (literalToken.TokenType == TokenType.Error)
{
token = new Token(TokenType.Error, literalEnd.Difference(stringKeeper));
return(true);
}
literalToken.TokenType = TokenType.DateTimeLiteral;
token = literalToken;
return(true);
}
newStringKeeper = stringKeeper;
token = null;
return(false);
}
private static bool TryTakeStringLiteral(StringKeeper stringKeeper, out StringKeeper newStringKeeper, out Token token)
{
if (stringKeeper.Next == '\'')
{
var start = stringKeeper.Take();
var work = new StringKeeper(start);
while (!work.IsEmpty)
{
if (work.IsNext("\'\'"))
{
work = work.Take(2);
}
else
{
if (work.Next == '\'')
{
var literalValue = work.Difference(start).Replace("''", "'");
token = new Token(TokenType.StringLiteral, literalValue);
work = work.Take();
newStringKeeper = work;
if (!IsTerminator(work))
{
do
{
work = work.Take();
} while (!work.IsEmpty && !work.IsWhitespace);
token.TokenType = TokenType.Error;
return(true);
}
return(true);
}
else
{
work = work.Take();
}
}
}
newStringKeeper = work;
token = new Token(TokenType.Error, work.Difference(stringKeeper));
return(true);
}
newStringKeeper = stringKeeper;
token = null;
return(false);
}
private static bool TryTakeParens(StringKeeper stringKeeper, out StringKeeper newStringKeeper, out Token token)
{
var thisParens = _parens.FirstOrDefault(x => stringKeeper.IsNext(x.Key));
if (thisParens.Key != null)
{
var work = stringKeeper.Take(thisParens.Key.Length);
newStringKeeper = work;
token = thisParens.Value;
return(true);
}
newStringKeeper = stringKeeper;
token = null;
return(false);
}
private static bool TryTakeOperator(StringKeeper stringKeeper, out StringKeeper newStringKeeper, out Token token)
{
var thisOp = _operators.FirstOrDefault(x => stringKeeper.IsNext(x.Key));
if (thisOp.Key != null)
{
var work = stringKeeper.Take(thisOp.Key.Length);
if (work.IsEmpty || work.IsWhitespace || work.IsNext("("))
{
newStringKeeper = work;
token = thisOp.Value;
return(true);
}
}
newStringKeeper = stringKeeper;
token = null;
return(false);
}
