protected override ExpressionBody Transform(Ast.LambdaExpression lmx)
{
var parameters = lmx.Parameters.Select(px => Tuple.Create(px, LX.Parameter(typeof(LogEventPropertyValue), px.ParameterName))).ToList();
var paramSwitcher = new ExpressionConstantMapper(parameters.ToDictionary(px => (object)px.Item1, px => (System.Linq.Expressions.Expression)px.Item2));
var rewritten = paramSwitcher.Visit(Transform(lmx.Body));
Type delegateType;
if (lmx.Parameters.Length == 1)
{
delegateType = typeof(Func <LogEventPropertyValue, LogEventPropertyValue>);
}
else if (lmx.Parameters.Length == 2)
{
delegateType = typeof(Func <LogEventPropertyValue, LogEventPropertyValue, LogEventPropertyValue>);
}
else
{
throw new NotSupportedException("Unsupported lambda signature.");
}
var lambda = LX.Lambda(delegateType, rewritten !, parameters.Select(px => px.Item2).ToArray());
// Unfortunately, right now, functions need to be threaded through in constant scalar values :-D
return(LX.New(typeof(ScalarValue).GetConstructor(new[] { typeof(object) }) !,
LX.Convert(lambda, typeof(object))));
}
public virtual Ast.Expression VisitLambdaExpression(Ast.LambdaExpression expression)
{
if (expression.Body != null)
{
return(this.Visit(expression.Body));
}
return(expression);
}
public override Ast.Expression VisitLambdaExpression(Ast.LambdaExpression expression)
{
WriteNewLine();
writer.Write("where");
WriteNewLine();
this.Visit(expression.Body);
return(expression);
}
