Hi all, I've recently switched my "Hums" UPnP server over to using WAI/Warp, but I'm seeing quite high CPU usage compared to monadic I/O. (1-7% with WAI as opposed to 0-1% for monadic). (Just to be clear: The server is using a constant amount of memory, so it's definitely not leaking or anything like that.) I think the source of the efficiency problem is that I'm enumerating strict ByteStrings from a file, but the WAI response enumerator requires Builder chunks, so I'm forced to use "fromByteString" to convert between the strict ByteString representation and the Builder representation -- I'm assuming this performs a memory copy. Is there any way to avoid this extra "fromByteString"? Other than this little issue, WAI seems to be working very well and it seems like a great fit if you just want low-level access to the HTTP protocol. On a slightly related note: Is there an elegant way to map enumerator chunk elements from type a -> b using a mapping function? Right now, I've embedded the ByteString -> Builder conversion deep in my enumerator, but it should really be happening at a higher level. Cheers, Bardur