gnu: Add ghc-utf8-string.

* gnu/packages/haskell.scm (ghc-utf8-string): New variable.

Signed-off-by: Eric Bavier <bavier@member.fsf.org>

gnu/packages/haskell.scm

@@ -441,6 +441,28 @@ http://web.cecs.pdx.edu/~mpj/pubs/springschool.html.")
      "Knowledge of GHC's installation directories.")
     (license bsd-3)))
 
+(define-public ghc-utf8-string
+  (package
+    (name "ghc-utf8-string")
+    (version "0.3.8")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (string-append
+             "http://hackage.haskell.org/package/utf8-string/utf8-string-"
+             version
+             ".tar.gz"))
+       (sha256
+        (base32 "1h29dn0scsfkhmkg14ywq9178lw40ah1r36w249zfzqr02y7qxc0"))))
+    (build-system haskell-build-system)
+    (home-page "http://github.com/glguy/utf8-string/")
+    (synopsis "Support for reading and writing UTF8 Strings")
+    (description
+     "A UTF8 layer for Strings. The utf8-string package provides operations
+for encoding UTF8 strings to Word8 lists and back, and for reading and writing
+UTF8 without truncation.")
+    (license bsd-3)))
+
 (define-public ghc-zlib
   (package
     (name "ghc-zlib")