utils: Use '@' for separating package names and version numbers.

This provides the ability to use numbers in package names.

Fixes <http://bugs.gnu.org/19219>.

* guix/utils.scm (package-name->name+version): New procedure.
* gnu/packages.scm (%find-package): Add a FALLBACK? keyword argument.
Use the previous method when no package is found.
(specification->package+output, specification->package): Adapt
documentation to new syntax.
* doc/guix.texi (Invoking guix package, Invoking guix import): Likewise.
* guix/ui.scm (package-specification->name+version+output): Likewise.
* guix/scripts/import/hackage.scm (show-help): Likewise.
* tests/guix-build.sh: Adapt to new syntax.
* tests/guix-lint.sh: Likewise.
* tests/guix-package.sh: Likewise.
* tests/ui.scm ("package-specification->name+version+output"): Likewise.
* tests/utils.scm ("package-name->name+version"): Likewise.
* NEWS: Mention new syntax.

3 files changed, 15 insertions, 6 deletions

diff --git a/guix/scripts/import/hackage.scm b/guix/scripts/import/hackage.scm
index 4e84278a78..f2c20026b6 100644
--- a/guix/scripts/import/hackage.scm
+++ b/guix/scripts/import/hackage.scm
@@ -46,7 +46,7 @@
 (define (show-help)
   (display (_ "Usage: guix import hackage PACKAGE-NAME
 Import and convert the Hackage package for PACKAGE-NAME.  If PACKAGE-NAME
-includes a suffix constituted by a dash followed by a numerical version (as
+includes a suffix constituted by a at-sign followed by a numerical version (as
 used with Guix packages), then a definition for the specified version of the
 package will be generated.  If no version suffix is pecified, then the
 generated package definition will correspond to the latest available
diff --git a/guix/ui.scm b/guix/ui.scm
index 7310773310..a3ec6834b6 100644
--- a/guix/ui.scm
+++ b/guix/ui.scm
@@ -1081,9 +1081,9 @@ package name, version number (or #f), and output name (or OUTPUT).  SPEC may
 optionally contain a version number and an output name, as in these examples:
 
   guile
-  guile-2.0.9
+  guile@2.0.9
   guile:debug
-  guile-2.0.9:debug
+  guile@2.0.9:debug
 "
   (let*-values (((name sub-drv)
                  (match (string-rindex spec #\:)
diff --git a/guix/utils.scm b/guix/utils.scm
index c61f105513..de541799fa 100644
--- a/guix/utils.scm
+++ b/guix/utils.scm
@@ -3,6 +3,7 @@
 ;;; Copyright © 2013, 2014, 2015 Mark H Weaver <mhw@netris.org>
 ;;; Copyright © 2014 Eric Bavier <bavier@member.fsf.org>
 ;;; Copyright © 2014 Ian Denhardt <ian@zenhack.net>
+;;; Copyright © 2016 Mathieu Lirzin <mthl@gnu.org>
 ;;; Copyright © 2015 David Thompson <davet@gnu.org>
 ;;;
 ;;; This file is part of GNU Guix.
@@ -31,8 +32,7 @@
   #:use-module (rnrs bytevectors)
   #:use-module (rnrs io ports)
   #:use-module ((rnrs bytevectors) #:select (bytevector-u8-set!))
-  #:use-module ((guix build utils)
-                #:select (dump-port package-name->name+version))
+  #:use-module ((guix build utils) #:select (dump-port))
   #:use-module ((guix build syscalls) #:select (errno mkdtemp!))
   #:use-module (ice-9 vlist)
   #:use-module (ice-9 format)
@@ -42,7 +42,6 @@
   #:use-module (ice-9 match)
   #:use-module (ice-9 format)
   #:use-module (system foreign)
-  #:re-export (package-name->name+version)
   #:export (bytevector->base16-string
             base16-string->bytevector
 
@@ -66,6 +65,7 @@
             gnu-triplet->nix-system
             %current-system
             %current-target-system
+            package-name->name+version
             version-compare
             version>?
             version>=?
@@ -544,6 +544,15 @@ returned by `config.guess'."
   ;; cross-building to.
   (make-parameter #f))
 
+(define (package-name->name+version spec)
+  "Given SPEC, a package name like \"foo@0.9.1b\", return two values: \"foo\"
+and \"0.9.1b\".  When the version part is unavailable, SPEC and #f are
+returned.  Both parts must not contain any '@'."
+  (match (string-rindex spec #\@)
+    (#f  (values spec #f))
+    (idx (values (substring spec 0 idx)
+                 (substring spec (1+ idx))))))
+
 (define version-compare
   (let ((strverscmp
          (let ((sym (or (dynamic-func "strverscmp" (dynamic-link))