<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd"> <pkgmetadata> <herd>haskell</herd> <maintainer> <email>haskell@gentoo.org</email> </maintainer> <longdescription> Differences lists: a list-like type supporting O(1) append. This is particularly useful for efficient logging and pretty printing, (e.g. with the Writer monad), where list append quickly becomes too expensive. </longdescription> </pkgmetadata>