Oh ok. Its not pseudocode, the combinators work :) I would put it the other way around. The http layer should not decide that the layer immediately above it mu

Oh ok. Its not pseudocode, the combinators work :) I would put it the other way around. The http layer should not decide that the layer immediately above it must be the one to handle all its errors. It should also be the one that defines the default (success) case and the error case, since those are defined by the HTTP protocol.