gnu: Add julia-nullables.

* gnu/packages/julia-xyz.scm (julia-nullables-0.0.8): New variable.

gnu/packages/julia-xyz.scm

@@ -1852,3 +1852,40 @@ read and write).  To avoid name conflicts, packages that provide support for
 standard file formats through functions named load and save are encouraged to
 extend the definitions here.")
     (license license:expat)))
+
+(define-public julia-nullables
+  (package
+    (name "julia-nullables")
+    (version "0.0.8")
+    (source
+     (origin
+       (method git-fetch)
+       (uri (git-reference
+             (url "https://github.com/JuliaAttic/Nullables.jl")
+             (commit (string-append "v" version))))
+       (file-name "Nullables")
+       (sha256
+        (base32 "00mdnk5hrl04wyw7g8dwybnxzn2wh0l52pa7398l3wggak2iqx1b"))))
+    (propagated-inputs `(("julia-compat" ,julia-compat)))
+    (build-system julia-build-system)
+    (arguments
+     `(#:phases
+       (modify-phases %standard-phases
+         (add-before 'precompile 'fix-toml
+           (lambda*
+               (#:key outputs source #:allow-other-keys)
+             (julia-create-package-toml
+              outputs source
+              "Nullables"
+              "4d1e1d77-625e-5b40-9113-a560ec7a8ecd"
+              "0.0.8"
+              '())
+             #t)))))
+    (home-page "https://github.com/JuliaAttic/Nullables.jl")
+    (synopsis "Nullable type for Julia")
+    (description "This package provides the Nullable type from Julia.  It also
+defines the unsafe_get and isnull functions, and all methods previously
+implemented in Julia Base: @code{get}, @code{eltype}, @code{convert},
+@code{promote}, @code{show}, @code{map}, @code{broadcast}, @code{filter},
+@code{isequal}, @code{isless} and @code{hash}.")
+    (license license:expat)))