internal static IEnumerable <DbExpression> FlattenAssociativeExpression(DbExpressionKind expressionKind, params DbExpression[] arguments)
{
if (!CommandTreeUtils._associativeExpressionKinds.Contains(expressionKind))
{
return((IEnumerable <DbExpression>)arguments);
}
List <DbExpression> argumentList = new List <DbExpression>();
foreach (DbExpression expression in arguments)
{
CommandTreeUtils.ExtractAssociativeArguments(expressionKind, argumentList, expression);
}
return((IEnumerable <DbExpression>)argumentList);
}
private static void ExtractAssociativeArguments(DbExpressionKind expressionKind, List <DbExpression> argumentList, DbExpression expression)
{
if (expression.ExpressionKind != expressionKind)
{
argumentList.Add(expression);
}
else
{
DbBinaryExpression binaryExpression = expression as DbBinaryExpression;
if (binaryExpression != null)
{
CommandTreeUtils.ExtractAssociativeArguments(expressionKind, argumentList, binaryExpression.Left);
CommandTreeUtils.ExtractAssociativeArguments(expressionKind, argumentList, binaryExpression.Right);
}
else
{
DbArithmeticExpression arithmeticExpression = (DbArithmeticExpression)expression;
CommandTreeUtils.ExtractAssociativeArguments(expressionKind, argumentList, arithmeticExpression.Arguments[0]);
CommandTreeUtils.ExtractAssociativeArguments(expressionKind, argumentList, arithmeticExpression.Arguments[1]);
}
}
}