gnu: crate: Add unicode-xid.

* gnu/local.mk: (GNU_SYSTEM_MODULES): Add packages/crates-io.scm.
* gnu/packages/crates-io.scm: New file, containing unicode-xid.

Signed-off-by: Chris Marusich <cmmarusich@gmail.com>

gnu/local.mk

@@ -121,6 +121,7 @@ GNU_SYSTEM_MODULES =				\
   %D%/packages/cpp.scm 				\
   %D%/packages/cppi.scm				\
   %D%/packages/cran.scm				\
+  %D%/packages/crates-io.scm			\
   %D%/packages/cross-base.scm			\
   %D%/packages/crypto.scm			\
   %D%/packages/cryptsetup.scm			\

gnu/packages/crates-io.scm

@@ -0,0 +1,45 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2019 Ivan Petkov <ivanppetkov@gmail.com>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (gnu packages crates-io)
+  #:use-module (guix build-system cargo)
+  #:use-module (guix download)
+  #:use-module ((guix licenses) #:prefix license:)
+  #:use-module (guix packages))
+
+(define-public rust-unicode-xid
+  (package
+    (name "rust-unicode-xid")
+    (version "0.1.0")
+    (source
+      (origin
+        (method url-fetch)
+        (uri (crate-uri "unicode-xid" version))
+        (file-name
+          (string-append name "-" version ".tar.gz"))
+        (sha256
+          (base32
+            "1z57lqh4s18rr4x0j4fw4fmp9hf9346h0kmdgqsqx0fhjr3k0wpw"))))
+    (build-system cargo-build-system)
+    (home-page
+      "https://github.com/unicode-rs/unicode-xid")
+    (synopsis "Determine Unicode XID related properties")
+    (description "Determine whether characters have the XID_Start
+or XID_Continue properties according to Unicode Standard Annex #31.")
+    ;; Dual licensed.
+    (license (list license:asl2.0 license:expat))))