private CodeSnippetExpression RewriteComprehensionExpression(CodeQueryExpression queryExpression)
{
using (StringWriter sw = new StringWriter(CultureInfo.InvariantCulture))
{
if (queryExpression.From != null)
{
sw.Write("(");
sw.Write("from " + queryExpression.InputParameterName + " in ");
this.generator.GenerateCodeFromExpression(queryExpression.From, sw, null);
sw.WriteLine();
}
if (queryExpression.OrderByKeySelectors.Count != 0)
{
sw.Write("orderby ");
for (int i = 0; i < queryExpression.OrderByKeySelectors.Count; i++)
{
var keySelector = queryExpression.OrderByKeySelectors[i];
this.generator.GenerateCodeFromExpression(keySelector, sw, null);
if (queryExpression.AreDescending[i])
{
sw.Write(" descending");
}
if (i != queryExpression.OrderByKeySelectors.Count - 1)
{
sw.Write(", ");
}
}
sw.WriteLine();
}
if (queryExpression.Where != null)
{
sw.Write("where ");
this.generator.GenerateCodeFromExpression(queryExpression.Where, sw, null);
sw.WriteLine();
}
if (queryExpression.GroupByKeySelector != null)
{
sw.Write("group " + queryExpression.InputParameterName + " by ");
this.generator.GenerateCodeFromExpression(queryExpression.GroupByKeySelector, sw, null);
sw.Write(" into " + queryExpression.GroupParameterName);
sw.WriteLine();
}
if (queryExpression.Select != null)
{
sw.Write("select ");
this.generator.GenerateCodeFromExpression(queryExpression.Select, sw, null);
sw.Write(")");
sw.WriteLine();
}
else
{
if (queryExpression.GroupByKeySelector != null)
{
sw.Write("select " + queryExpression.GroupParameterName);
sw.Write(")");
}
else
{
sw.Write("select " + queryExpression.InputParameterName);
sw.Write(")");
}
sw.WriteLine();
}
return new CodeSnippetExpression(sw.ToString());
}
}
/// <summary>
/// Get the group Parameter Name
/// </summary>
/// <param name="codeQuerySource">Input code query Source</param>
/// <returns>Group Parameter Name</returns>
protected string GetGroupParameterName(CodeQueryExpression codeQuerySource)
{
bool shouldCreateNewGroupParameter = codeQuerySource == null || codeQuerySource.GroupByKeySelector != null;
if (shouldCreateNewGroupParameter)
{
return this.ParameterNameGenerator.GenerateIdentifier("g");
}
else
{
return codeQuerySource.GroupParameterName;
}
}