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.

NEWS

@@ -14,18 +14,30 @@ Please send Guix bug reports to bug-guix@gnu.org.
 
 ** Package management
 
+*** New syntax for separating package names and version numbers
+
+Use ‘@’ instead of ‘-’ as a separator, as in ‘gnupg@2.0’.  This new separator
+is a reserved character which is not allowed both in package names and version
+numbers.
+
+The old syntax to specify a package’s version—e.g., as “gnupg-2.0”—is obsolete
+and support for it will be removed in the future.
+
 *** Emacs interface for licenses
 *** Emacs interface for system generations
 *** Emacs interface for hydra.gnu.org
 *** Changes in Emacs interface variables and faces
+
 In the following names, BUFFER-TYPE means "info" or "list";
 ENTRY-TYPE means "package", "output" or "generation".
 
 **** Removed
+
 - guix-info-fill-column
 - guix-info-insert-ENTRY-TYPE-function
 
 **** Renamed
+
 - guix-info-ignore-empty-vals -> guix-info-ignore-empty-values
 - guix-output-name-width -> guix-generation-output-name-width
 - guix-buffer-name-function -> guix-ui-buffer-name-function
@@ -34,6 +46,7 @@ ENTRY-TYPE means "package", "output" or "generation".
 - guix-BUFFER-TYPE-file-path (face) -> guix-BUFFER-TYPE-file-name
 
 **** Replaced
+
 - guix-list-column-format, guix-list-column-value-methods ->
   guix-ENTRY-TYPE-list-format
 - guix-info-displayed-params, guix-info-insert-methods,
@@ -44,6 +57,10 @@ ENTRY-TYPE means "package", "output" or "generation".
   guix-ENTRY-TYPE-list-describe-warning-count
 - guix-package-info-fill-heading -> guix-info-fill
 
+** Noteworthy bug fixes
+
+*** Numbers in package names are correctly handled (http://bugs.gnu.org/19219)
+
 * Changes in 0.9.0 (since 0.8.3)
 
 ** Package management

doc/guix.texi

@@ -13,7 +13,7 @@
 Copyright @copyright{} 2012, 2013, 2014, 2015, 2016 Ludovic Courtès@*
 Copyright @copyright{} 2013, 2014, 2016 Andreas Enge@*
 Copyright @copyright{} 2013 Nikita Karetnikov@*
-Copyright @copyright{} 2015 Mathieu Lirzin@*
+Copyright @copyright{} 2015, 2016 Mathieu Lirzin@*
 Copyright @copyright{} 2014 Pierre-Antoine Rault@*
 Copyright @copyright{} 2015 Taylan Ulrich Bayırlı/Kammer@*
 Copyright @copyright{} 2015, 2016 Leo Famulari
@@ -1285,14 +1285,14 @@ The @var{options} can be among the following:
 Install the specified @var{package}s.
 
 Each @var{package} may specify either a simple package name, such as
-@code{guile}, or a package name followed by a hyphen and version number,
-such as @code{guile-1.8.8} or simply @code{guile-1.8} (in the latter
+@code{guile}, or a package name followed by an at-sign and version number,
+such as @code{guile@@1.8.8} or simply @code{guile@@1.8} (in the latter
 case, the newest version prefixed by @code{1.8} is selected.)
 
 If no version number is specified, the
 newest available version will be selected.  In addition, @var{package}
 may contain a colon, followed by the name of one of the outputs of the
-package, as in @code{gcc:doc} or @code{binutils-2.22:lib}
+package, as in @code{gcc:doc} or @code{binutils@@2.22:lib}
 (@pxref{Packages with Multiple Outputs}).  Packages with a corresponding
 name (and optionally version) are searched for among the GNU
 distribution modules (@pxref{Package Modules}).
@@ -4522,10 +4522,10 @@ guix import hackage -t -e "'((\"network-uri\" . false))" HTTP
 @end example
 
 A specific package version may optionally be specified by following the
-package name by a hyphen and a version number as in the following example:
+package name by an at-sign and a version number as in the following example:
 
 @example
-guix import hackage mtl-2.1.3.1
+guix import hackage mtl@@2.1.3.1
 @end example
 
 @item elpa

gnu/packages.scm

@@ -282,7 +282,7 @@ return its return value."
 ;;; Package specification.
 ;;;
 
-(define (%find-package spec name version)
+(define* (%find-package spec name version #:key fallback?)
   (match (find-best-packages-by-name name version)
     ((pkg . pkg*)
      (unless (null? pkg*)
@@ -290,15 +290,23 @@ return its return value."
        (warning (_ "choosing ~a from ~a~%")
                 (package-full-name pkg)
                 (location->string (package-location pkg))))
+     (when fallback?
+       (warning (_ "deprecated NAME-VERSION syntax.~%")))
      pkg)
     (_
      (if version
          (leave (_ "~A: package not found for version ~a~%") name version)
-         (leave (_ "~A: unknown package~%") name)))))
+         (or fallback?
+             ;; XXX: Fallback to the older specification style with an hyphen
+             ;; between NAME and VERSION, for backward compatibility.
+             (let ((proc (@ (guix build utils) package-name->name+version)))
+               (call-with-values (proc name)
+                 (cut %find-package spec <> <> #:fallback? #t)))
+             (leave (_ "~A: unknown package~%") name))))))
 
 (define (specification->package spec)
   "Return a package matching SPEC.  SPEC may be a package name, or a package
-name followed by a hyphen and a version number.  If the version number is not
+name followed by an at-sign and a version number.  If the version number is not
 present, return the preferred newest version."
   (let-values (((name version) (package-name->name+version spec)))
     (%find-package spec name version)))
@@ -308,9 +316,9 @@ present, return the preferred newest version."
 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
 
 If SPEC does not specify a version number, return the preferred newest
 version; if SPEC does not specify an output, return OUTPUT."

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

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 #\:)

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))

tests/guix-build.sh

@@ -161,8 +161,8 @@ then false; else true; fi
 
 # Parsing package names and versions.
 guix build -n time		# PASS
-guix build -n time-1.7		# PASS, version found
-if guix build -n time-3.2;	# FAIL, version not found
+guix build -n time@1.7		# PASS, version found
+if guix build -n time@3.2;	# FAIL, version not found
 then false; else true; fi
 if guix build -n something-that-will-never-exist; # FAIL
 then false; else true; fi

tests/guix-lint.sh

@@ -75,4 +75,4 @@ if guix lint -c synopsis,invalid-checker dummy 2>&1 | \
 then true; else false; fi
 
 # Make sure specifying multiple packages works.
-guix lint -c inputs-should-be-native dummy dummy-42 dummy
+guix lint -c inputs-should-be-native dummy dummy@42 dummy

tests/guix-package.sh

@@ -207,13 +207,13 @@ cat > "$module_dir/foo.scm"<<EOF
 EOF
 
 guix package -A emacs-foo-bar -L "$module_dir" | grep 42
-guix package -i emacs-foo-bar-42 -n -L "$module_dir"
+guix package -i emacs-foo-bar@42 -n -L "$module_dir"
 
 # Same thing using the 'GUIX_PACKAGE_PATH' environment variable.
 GUIX_PACKAGE_PATH="$module_dir"
 export GUIX_PACKAGE_PATH
 guix package -A emacs-foo-bar | grep 42
-guix package -i emacs-foo-bar-42 -n
+guix package -i emacs-foo-bar@42 -n
 
 # Make sure patches that live under $GUIX_PACKAGE_PATH are found.
 cat > "$module_dir/emacs.patch"<<EOF

tests/ui.scm

@@ -108,10 +108,10 @@ Second line" 24))
                (package-specification->name+version+output spec))
            list))
        '("guile"
-         "guile-2.0.9"
+         "guile@2.0.9"
          "guile:debug"
-         "guile-2.0.9:debug"
-         "guile-cairo-1.4.1")))
+         "guile@2.0.9:debug"
+         "guile-cairo@1.4.1")))
 
 (test-equal "integer"
   '(1)

tests/utils.scm

@@ -1,6 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2012, 2013, 2014, 2015, 2016 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2014 Eric Bavier <bavier@member.fsf.org>
+;;; Copyright © 2016 Mathieu Lirzin <mthl@gnu.org>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -59,14 +60,14 @@
           ((name version)
            (let*-values (((full-name)
                           (if version
-                              (string-append name "-" version)
+                              (string-append name "@" version)
                               name))
                          ((name* version*)
                           (package-name->name+version full-name)))
              (and (equal? name* name)
                   (equal? version* version)))))
          '(("foo" "0.9.1b")
-           ("foo-bar" "1.0")
+           ("foo-14-bar" "320")
            ("foo-bar2" #f)
            ("guile" "2.0.6.65-134c9") ; as produced by `git-version-gen'
            ("nixpkgs" "1.0pre22125_a28fe19")