internal static bool TryParseIdentifier(string sql, int position, out RawToken token)
{
if (char.IsLetter(sql[position]))
{
var start = position;
position++;
while (sql.TryElementAt(position, out var next) &&
(char.IsLetterOrDigit(next) || next == '_'))
{
position++;
}
token = new RawToken(SqlKind.Identifier, start, position);
return(true);
}
if (sql.TryElementAt(position, out var c) &&
c == '"')
{
var start = position;
position++;
token = SkipNext(sql, '"', ref position)
? new RawToken(SqlKind.QuotedIdentifier, start, position)
: new RawToken(SqlKind.QuotedIdentifier, start, sql.Length);
return(true);
}
token = default;
return(false);
}
internal static bool TryParseNumber(string sql, int position, out RawToken token)
{
if (char.IsDigit(sql[position]))
{
var start = position;
position++;
while (sql.TryElementAt(position, out var next) &&
char.IsDigit(next))
{
position++;
}
if (sql.TryElementAt(position, out var c) &&
c == '.')
{
position++;
while (sql.TryElementAt(position, out var next) &&
char.IsDigit(next))
{
position++;
}
token = new RawToken(SqlKind.Float, start, position);
}
else
{
token = new RawToken(SqlKind.Integer, start, position);
}
return(true);
}
token = default;
return(false);
}
internal static bool TryParse(string sql, int position, string expected, SqlKind kind, out RawToken token)
{
if (TryMatch(sql, position, expected))
{
token = new RawToken(kind, position, position + expected.Length);
return(true);
}
token = default;
return(false);
}
private static bool IsReservedKeyword(string sql, RawToken token)
{
foreach (var keyword in Keywords.Reserved)
{
if (TryMatchKeyword(sql, token, keyword))
{
return(true);
}
}
return(false);
}
internal static bool TryParse(string sql, int position, char expected, SqlKind kind, out RawToken token)
{
if (sql.TryElementAt(position, out var c) &&
c == expected)
{
token = RawToken.SingleChar(kind, position);
return(true);
}
token = default;
return(false);
}
private static bool TryMatchKeyword(string sql, RawToken token, string keyword)
{
if (token.Kind == SqlKind.Identifier &&
token.Length == keyword.Length)
{
for (int i = 0; i < token.Length; i++)
{
if (char.ToUpper(sql[token.Start + i]) != keyword[i])
{
return(false);
}
}
return(true);
}
return(false);
}
internal static bool TryParseComment(string sql, int position, out RawToken token)
{
if (TryMatch(sql, position, "--"))
{
var start = position;
position += 2;
if (SkipNext(sql, '\n', ref position) ||
position == sql.Length)
{
var end = position;
if (sql[position - 2] == '\r')
{
end -= 2;
}
else if (sql[position - 1] == '\n')
{
end -= 1;
}
token = new RawToken(SqlKind.SingleLineCommentTrivia, start, end);
}
else
{
token = new RawToken(SqlKind.SingleLineCommentTrivia, start, sql.Length);
}
return(true);
}
if (TryMatch(sql, position, "/*"))
{
var start = position;
position += 2;
token = SkipNext(sql, "*/", ref position)
? new RawToken(SqlKind.MultiLineCommentTrivia, start, position)
: new RawToken(SqlKind.MultiLineCommentTrivia, start, sql.Length);
return(true);
}
token = default;
return(false);
}
internal static bool TryParseString(string sql, int position, out RawToken token)
{
if (sql[position] == '\'')
{
var start = position;
position++;
if (SkipNext(sql, '\'', ref position))
{
token = new RawToken(SqlKind.String, start, position);
}
else
{
token = new RawToken(SqlKind.String, start, sql.Length);
}
return(true);
}
token = default;
return(false);
}
public SqlLiteral(string sql, RawToken token)
: base(sql, ImmutableArray <SqlNode> .Empty)
{
this.Token = token.WithParent(this);
}
private static bool TryMatchKeyword(string sql, ImmutableArray <RawToken> tokens, int position, string keyword, out RawToken token)
{
if (TryMatch(tokens, position, SqlKind.Identifier, out token) &&
TryMatchKeyword(sql, token, keyword))
{
return(true);
}
token = default;
return(false);
}
private static bool TryMatch(ImmutableArray <RawToken> tokens, int position, SqlKind kind, out RawToken token)
{
if (tokens.TryElementAt(position, out token) &&
token.Kind == kind)
{
return(true);
}
token = default;
return(false);
}
private static bool TryAs(string sql, ImmutableArray <RawToken> tokens, ref int position, out RawToken @as, out SqlSimpleName name)
{
name = null;
if (TryMatchKeyword(sql, tokens, position, "AS", out @as))
{
position++;
if (SqlSimpleName(sql, tokens, ref position, allowKeyword: true) is SqlSimpleName simpleName)
{
name = simpleName;
}
return(true);
}
return(false);
}
public static ImmutableArray <RawToken> Tokens(string sql)
{
if (string.IsNullOrEmpty(sql))
{
return(ImmutableArray <RawToken> .Empty);
}
var tokens = new List <RawToken>();
var position = 0;
while (position < sql.Length)
{
TokenParser.SkipWhitespace(sql, ref position);
if (TokenParser.TryParseNumber(sql, position, out var token) ||
TokenParser.TryParseString(sql, position, out token) ||
TokenParser.TryParseComment(sql, position, out token) ||
TokenParser.TryParseIdentifier(sql, position, out token) ||
TokenParser.TryParse(sql, position, "<>", SqlKind.NotEqualsToken, out token) ||
TokenParser.TryParse(sql, position, "<=", SqlKind.LessThanEqualsToken, out token) ||
TokenParser.TryParse(sql, position, ">=", SqlKind.GreaterThanEqualsToken, out token) ||
TokenParser.TryParse(sql, position, "|/", SqlKind.SquareRootToken, out token) ||
TokenParser.TryParse(sql, position, "||/", SqlKind.CubeRootToken, out token) ||
TokenParser.TryParse(sql, position, "!!", SqlKind.ExclamationExclamationToken, out token) ||
TokenParser.TryParse(sql, position, "<<", SqlKind.LessThanLessThanToken, out token) ||
TokenParser.TryParse(sql, position, ">>", SqlKind.GreaterThanGreaterThanToken, out token) ||
TokenParser.TryParse(sql, position, '+', SqlKind.PlusToken, out token) ||
TokenParser.TryParse(sql, position, '-', SqlKind.MinusToken, out token) ||
TokenParser.TryParse(sql, position, '*', SqlKind.AsteriskToken, out token) ||
TokenParser.TryParse(sql, position, '/', SqlKind.SlashToken, out token) ||
TokenParser.TryParse(sql, position, '^', SqlKind.ExponentToken, out token) ||
TokenParser.TryParse(sql, position, '%', SqlKind.PercentToken, out token) ||
TokenParser.TryParse(sql, position, '@', SqlKind.AtToken, out token) ||
TokenParser.TryParse(sql, position, '!', SqlKind.ExclamationToken, out token) ||
TokenParser.TryParse(sql, position, '&', SqlKind.AmpersandToken, out token) ||
TokenParser.TryParse(sql, position, '|', SqlKind.BarToken, out token) ||
TokenParser.TryParse(sql, position, '#', SqlKind.HashToken, out token) ||
TokenParser.TryParse(sql, position, '~', SqlKind.TildeToken, out token) ||
TokenParser.TryParse(sql, position, '=', SqlKind.EqualsToken, out token) ||
TokenParser.TryParse(sql, position, '<', SqlKind.LessThanEqualsToken, out token) ||
TokenParser.TryParse(sql, position, '>', SqlKind.GreaterThanToken, out token) ||
TokenParser.TryParse(sql, position, '(', SqlKind.OpenParenToken, out token) ||
TokenParser.TryParse(sql, position, ')', SqlKind.CloseParenToken, out token) ||
TokenParser.TryParse(sql, position, '[', SqlKind.OpenBracketToken, out token) ||
TokenParser.TryParse(sql, position, ']', SqlKind.CloseBracketToken, out token) ||
TokenParser.TryParse(sql, position, '.', SqlKind.DotToken, out token) ||
TokenParser.TryParse(sql, position, ',', SqlKind.CommaToken, out token) ||
TokenParser.TryParse(sql, position, ';', SqlKind.SemicolonToken, out token) ||
TokenParser.TryParse(sql, position, ':', SqlKind.ColonToken, out token))
{
position = token.End;
tokens.Add(token);
}
else
{
tokens.Add(RawToken.SingleChar(SqlKind.Unknown, position));
position++;
}
}
return(tokens.ToImmutableArray());
}
public QuotedIdentifier(string sql, RawToken identifier)
: base(sql, ImmutableArray <SqlNode> .Empty)
{
this.Identifier = identifier.WithParent(this);
}