indexed variants.")
(license license:bsd-3)))
+(define-public ghc-lens-family-core
+ (package
+ (name "ghc-lens-family-core")
+ (version "1.2.3")
+ (source
+ (origin
+ (method url-fetch)
+ (uri (string-append
+ "mirror://hackage/package/lens-family-core/lens-family-core-"
+ version
+ ".tar.gz"))
+ (sha256
+ (base32
+ "009rf10pj1cb50v44cc1pq7qvfrmkkk9dikahs9qmvbvgl3mykwi"))))
+ (build-system haskell-build-system)
+ (home-page
+ "http://hackage.haskell.org/package/lens-family-core")
+ (synopsis "Haskell 98 Lens Families")
+ (description
+ "This package provides first class functional references. In addition to
+the usual operations of getting, setting and composition, plus integration
+with the state monad, lens families provide some unique features:
+
+@itemize
+@item Polymorphic updating
+@item Traversals
+@item Cast projection functions to read-only lenses
+@item Cast @code{toList} functions to read-only traversals
+@item Cast semantic editor combinators to modify-only traversals
+@end itemize
+
+For optimal first-class support use the lens-family package with rank 2/rank N
+polymorphism. @code{Lens.Family.Clone} allows for first-class support of
+lenses and traversals for those who require Haskell 98.")
+ (license license:bsd-3)))
+
(define-public ghc-libffi
(package
(name "ghc-libffi")