private ISqlNode ParseFunctionCall(ITokenizer t)
{
var name = t.GetNext();
if (name.Type != SqlTokenType.Keyword && name.Type != SqlTokenType.Identifier)
{
throw ParsingException.UnexpectedToken(SqlTokenType.Identifier, name);
}
// "COUNT" "(" "*" ")"
if (name.IsKeyword("COUNT"))
{
var openParen = t.Expect(SqlTokenType.Symbol, "(");
var maybeStar = t.Peek();
if (maybeStar.IsSymbol("*"))
{
t.GetNext();
t.Expect(SqlTokenType.Symbol, ")");
return(new SqlFunctionCallNode
{
Location = name.Location,
Name = new SqlKeywordNode(name),
Arguments = new SqlListNode <ISqlNode> {
new SqlOperatorNode(maybeStar)
}
});
}
// It's not *, so put everything back, fallthrough, and let the rest of the parsing happen
t.PutBack(openParen);
}
// TODO: "CONVERT" "(" <DataType>, <ScalarExpression> ("," <int>)? ")"
// "CAST" "(" <ScalarExpression> "AS" <DataType> ")"
if (name.IsKeyword("CAST"))
{
t.Expect(SqlTokenType.Symbol, "(");
var first = ParseScalarExpression(t);
t.Expect(SqlTokenType.Keyword, "AS");
var type = ParseDataType(t);
t.Expect(SqlTokenType.Symbol, ")");
return(new SqlCastNode
{
Location = name.Location,
Expression = first,
DataType = type
});
}
// <Name> "(" <ScalarExpressionList> ")"
return(new SqlFunctionCallNode
{
Location = name.Location,
Name = Facts.IsBuiltInFunctionName(name.Value) ? (ISqlNode) new SqlKeywordNode(name.Value.ToUpperInvariant(), name.Location) : new SqlIdentifierNode(name),
Arguments = ParseParenthesis(t, x => ParseList(x, ParseScalarExpression)).Expression
});
}
public static SqlToken ExpectPeek(this ITokenizer ITokenizer, SqlTokenType type)
{
var found = ITokenizer.Peek();
if (found.Type != type)
{
throw ParsingException.UnexpectedToken(type, found);
}
return(found);
}
public static SqlToken GetIdentifierOrKeyword(this ITokenizer ITokenizer)
{
var next = ITokenizer.GetNext();
if (next.IsType(SqlTokenType.Identifier) || next.IsType(SqlTokenType.Keyword))
{
return(next);
}
throw ParsingException.UnexpectedToken(SqlTokenType.Identifier, next);
}
public static SqlToken Expect(this ITokenizer ITokenizer, SqlTokenType type, params string[] values)
{
var found = ITokenizer.GetNext();
if (found.Type == type)
{
foreach (var value in values)
{
if (found.Value == value)
{
return(found);
}
}
}
throw ParsingException.UnexpectedToken(type, values, found);
}