I have HTTP-3001.0.4 and I like to check the HTTP response headers before downloading the entire document. I hesitate to do a HEAD request first and then a separate GET request, because there is a (little, but not zero) chance, that the document changes between both requests. I hoped that simpleHTTP is lazy enough, so that I can check the rspHeaders field of the HTTP response and that only touching rspBody would download the document content. Unfortunately simpleHTTP downloads the entire document before I can access the HTTP header. To be honest, I would also like to fetch the content of the document lazily. Actually, if simpleHTTP would behave lazy, I suspect this requires using unsafeInterleaveIO internally, which is considered a hack. Is this the reason why simpleHTTP is not lazy? Or do I just need a lazy Stream type for this purpose?