/// <summary>
/// Tries to parse a collection of function parameters. Allows path and filter to share the core algorithm while representing parameters differently.
/// </summary>
/// <param name="lexer">The lexer to read from.</param>
/// <param name="endTokenKind">The token kind that marks the end of the parameters.</param>
/// <param name="splitParameters">The parameters if they were successfully split.</param>
/// <returns>Whether the parameters could be split.</returns>
private static bool TrySplitFunctionParameters(this ExpressionLexer lexer, ExpressionTokenKind endTokenKind, out ICollection <FunctionParameterToken> splitParameters)
{
DebugUtils.CheckNoExternalCallers();
Debug.Assert(lexer != null, "lexer != null");
var parameters = new List <FunctionParameterToken>();
splitParameters = parameters;
ExpressionToken currentToken = lexer.CurrentToken;
if (currentToken.Kind == endTokenKind)
{
return(true);
}
if (currentToken.Kind != ExpressionTokenKind.Identifier || lexer.PeekNextToken().Kind != ExpressionTokenKind.Equal)
{
return(false);
}
while (currentToken.Kind != endTokenKind)
{
lexer.ValidateToken(ExpressionTokenKind.Identifier);
string identifier = lexer.CurrentToken.GetIdentifier();
lexer.NextToken();
lexer.ValidateToken(ExpressionTokenKind.Equal);
lexer.NextToken();
QueryToken parameterValue;
if (!TryCreateParameterValueToken(lexer.CurrentToken, out parameterValue))
{
throw new ODataException(ODataErrorStrings.ExpressionLexer_SyntaxError(lexer.Position, lexer.ExpressionText));
}
parameters.Add(new FunctionParameterToken(identifier, parameterValue));
// Read the next parameterToken. We should be at the end, or find
// we have a comma followed by something.
lexer.NextToken();
currentToken = lexer.CurrentToken;
if (currentToken.Kind == ExpressionTokenKind.Comma)
{
lexer.NextToken();
currentToken = lexer.CurrentToken;
if (currentToken.Kind == endTokenKind)
{
// Trailing comma.
throw new ODataException(ODataErrorStrings.ExpressionLexer_SyntaxError(lexer.Position, lexer.ExpressionText));
}
}
}
return(true);
}