protected TextSpan ReadBatchVariable(TextSpan head)
{
if (!TryNextChar('(', out var lrent))
{
return(TextSpan.Empty);
}
head = head.Concat(lrent);
var identifier = ReadIdentifier(head);
if (identifier.Length == 2)
{
return(TextSpan.Empty);
}
if (!TryNextChar(')', out var rrent))
{
return(TextSpan.Empty);
}
var token = identifier.Concat(rrent);
token.Type = SqlToken.BatchVariable.ToString();
return(token);
}
private TextSpan ReadMagnetCompareSymbol(TextSpan head)
{
var startIndex = GetOffset();
var index = 0;
var sb = new StringBuilder();
sb.Append(GetSpanString(head));
do
{
var ch = PeekCh(index);
if (ch == char.MinValue)
{
break;
}
if (!char.IsWhiteSpace(ch))
{
sb.Append(ch);
break;
}
index++;
} while (true);
var tail = new TextSpan
{
Offset = startIndex,
Length = index + 1
};
var peekSymbol = sb.ToString();
if (index > 0 && _symbolToTokenTypeMap.ContainsKey(peekSymbol))
{
SetOffset(tail.Offset + tail.Length);
var span = head.Concat(tail);
span.Type = _symbolToTokenTypeMap[peekSymbol];
return(span);
}
return(TextSpan.Empty);
}
protected override bool TryScanNext(TextSpan headSpan, out TextSpan tokenSpan)
{
tokenSpan = TextSpan.Empty;
var head = GetSpanString(headSpan)[0];
if (head == ':' && TryNextChar('r', out var refSpan))
{
tokenSpan = headSpan.Concat(refSpan);
tokenSpan = ReadBatchReferenceFile(tokenSpan);
tokenSpan.Type = SqlToken.BatchRefFile.ToString();
return(true);
}
if (head == 'N' && TryNextChar('\'', out var head2))
{
headSpan = headSpan.Concat(head2);
if (!TryRead(ReadQuoteString, headSpan, out var nstring))
{
ThrowHelper.ThrowScanException(this, $"Scan NString Error.");
}
nstring.Type = SqlToken.NString.ToString();
tokenSpan = nstring;
return(true);
}
if (head == '0' && TryNextChar('x', out var hexHead))
{
headSpan = headSpan.Concat(hexHead);
if (!TryRead(ReadHexNumber, headSpan, out var hexString))
{
ThrowHelper.ThrowScanException(this, $"Scan HexString Error.");
}
tokenSpan = hexString;
return(true);
}
if (char.IsDigit(head))
{
if (!TryRead(ReadNumber, headSpan, out var numberString))
{
ThrowHelper.ThrowScanException(this, $"Scan number Error.");
}
if (TryNextChar('.', out var floatHead))
{
headSpan = numberString.Concat(floatHead);
if (!TryRead(ReadNumber, headSpan, out var floatString))
{
ThrowHelper.ThrowScanException(this, $"Scan float Error.");
}
tokenSpan = floatString;
tokenSpan.Type = SqlToken.Number.ToString();
return(true);
}
tokenSpan = numberString;
tokenSpan.Type = SqlToken.Number.ToString();
return(true);
}
if (head == '[' && TryRead(ReadSqlIdentifier, headSpan, out var sqlIdentifier))
{
tokenSpan = sqlIdentifier;
return(true);
}
var nextChar = PeekCh();
if (head == ':' && char.IsLetter(nextChar) && TryRead(ReadIdentifier, headSpan, out var scriptIdentifier))
{
scriptIdentifier.Type = GetTokenType(scriptIdentifier, SqlToken.ScriptIdentifier);
tokenSpan = scriptIdentifier;
return(true);
}
if (head == '/' && TryRead(ReadMultiComment, headSpan, out var multiComment))
{
tokenSpan = multiComment;
return(true);
}
if (head == '-' && TryNextChar('-', out var singleHead))
{
headSpan = headSpan.Concat(singleHead);
if (!TryRead(ReadSingleComment, headSpan, out var singleComment))
{
ThrowHelper.ThrowScanException(this, $"Scan single comment Error.");
}
tokenSpan = singleComment;
return(true);
}
if (head == '\"' && TryRead(ReadDoubleQuoteString, headSpan, out var doubleQuoteString))
{
tokenSpan = doubleQuoteString;
return(true);
}
if (head == '\'' && TryRead(ReadQuoteString, headSpan, out var quoteString))
{
tokenSpan = quoteString;
return(true);
}
if (head == '@' && TryNextChar('@', out var atHead2))
{
headSpan = headSpan.Concat(atHead2);
if (!TryRead(ReadIdentifier, headSpan, out var sysVariable))
{
throw new ScanException("Expect @@xxxx");
}
tokenSpan = sysVariable;
tokenSpan.Type = SqlToken.SystemVariable.ToString();
return(true);
}
if (head == '@' && TryRead(ReadIdentifier, headSpan, out var variable))
{
tokenSpan = variable;
tokenSpan.Type = SqlToken.Variable.ToString();
return(true);
}
if (head == '#' && TryRead(ReadIdentifier, headSpan, out var tmpTable))
{
tokenSpan = tmpTable;
tokenSpan.Type = SqlToken.TempTable.ToString();
return(true);
}
if (head == '$' && TryRead(ReadBatchVariable, headSpan, out var nameSpan))
{
tokenSpan = nameSpan;
return(true);
}
if (_magnetHeadChars.Contains(head) && TryRead(ReadMagnetCompareSymbol, headSpan, out var magnetSymbol))
{
tokenSpan = magnetSymbol;
return(true);
}
return(false);
}
