* gnu/packages/haskell.scm (ghc-dlist): New variable.
---
gnu/packages/haskell.scm | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/gnu/packages/haskell.scm b/gnu/packages/haskell.scm
index 8c05c47..2da5f7f 100644
--- a/gnu/packages/haskell.scm
+++ b/gnu/packages/haskell.scm
@@ -357,6 +357,29 @@ package.")
package.")
(license bsd-3)))
+(define-public ghc-dlist
+ (package
+ (name "ghc-dlist")
+ (version "0.7.1.1")
+ (source
+ (origin
+ (method url-fetch)
+ (uri (string-append
+ "http://hackage.haskell.org/package/dlist/dlist-";
+ version
+ ".tar.gz"))
+ (sha256
+ (base32 "1zayvxvkan2s2ixajdr3f5rn1gzhprzv6cww4cbpwjhzw0l7zc08"))))
+ (arguments `(#:tests? #f))
+ (build-system haskell-build-system)
+ (home-page "https://github.com/spl/dlist";)
+ (synopsis "Difference lists")
+ (description
+ "Difference lists are 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.")
+ (license bsd-3)))
+
(define-public ghc-mtl
(package
(name "ghc-mtl")
--
2.4.3
