/// <inheritdoc/>
protected override Expression VisitLambda(LambdaExpression l)
{
Expression body = Visit(l.Body);
if (body != l.Body)
{
return(FastExpression.Lambda(l.Type, body, l.Parameters));
}
return(l);
}
/// <summary>
/// Extracts constants from <see cref="LambdaExpression"/> specified in constructor.
/// Result is a <see cref="LambdaExpression"/> with one additional parameter (array of objects).
/// Extra parameter is added to first position.
/// </summary>
/// <returns><see cref="LambdaExpression"/> with all constants extracted to additional parameter.</returns>
public LambdaExpression Process()
{
if (constantValues != null)
{
throw new InvalidOperationException();
}
constantValues = new List <object>();
var parameters = EnumerableUtils.One(constantParameter).Concat(lambda.Parameters).ToArray();
var body = Visit(lambda.Body);
// Preserve original delegate type because it may differ from types of parameters / return value
return(FastExpression.Lambda(FixDelegateType(lambda.Type), body, parameters));
}