Make it possible to rename 'v0'

3 files changed, 33 insertions, 6 deletions

diff --git a/Changes b/Changes
index 0ab79cf..ee19047 100644
--- a/Changes
+++ b/Changes
@@ -1,5 +1,7 @@
 {{$NEXT}}
 
+    - Allow renaming of the 'v0' version set
+
 0.017     2016-08-20 22:57:17-07:00 America/Los_Angeles (TRIAL RELEASE)
 
     - Add on_use/sub EXPORT_ON_USE { ... } feature
diff --git a/lib/Importer.pm b/lib/Importer.pm
index 024860a..8ae5e7b 100644
--- a/lib/Importer.pm
+++ b/lib/Importer.pm
@@ -424,8 +424,9 @@ sub _build_menu {
 
     my $common_v = delete $export_vers->{'*'};
 
+    my $root_ver = delete $export_vers->{'root_name'} || 'v0';
     my $versions = {
-        v0 => { # Add base as v0, do not use the same hashref to avoid self-refrencing
+        $root_ver => { # Add root as v0 or root_name, do not use the same hashref to avoid self-refrencing
             lookup   => $lookup,
             exports  => $exports,
             fail     => $fail,
@@ -643,7 +644,7 @@ sub { *{"$into\\::\$_[0]"} = \$_[1] }
     EOT
 
     my $menu = $main_menu;
-    my $ver = 'v0';
+    my $ver = '<NO VERSION SPECIFIED>';
     my $ver_str = "";
     my %used;
     for my $set (@$import) {
@@ -974,7 +975,7 @@ to provide alternate versions of exports. This is useful for maintaining
 backwards compatibility while providing a path forward.
 
 Importing without specifying a version set uses the default version set, which
-is also called 'v0'.
+is usually called 'v0', but can be given a different name by an exporter.
 
 You can specify an alternate version set with the '+' prefix:
 
@@ -1006,7 +1007,8 @@ v0 set.
 =back
 
 Not all exporters provide versioned exports, but '+v0' is automatically
-generated and always present.
+generated and always present (though may be given a different name by the
+exporter).
 
 See L</%EXPORT_VERSIONS> for details on providing version-sets from an
 exporter.
@@ -1198,6 +1200,10 @@ changes.
     );
 
     our %EXPORT_VERSIONS = (
+        # The 'root_name' option is special, ot lets you rename 'v0' to
+        # anything you want.
+        root_name => 'v0',
+
         # The '*' version is special, it gets mixed into all versions
         # (including v0 and the root menu).
         '*' => {
diff --git a/t/versions.t b/t/versions.t
index 2bb8061..2e70245 100644
--- a/t/versions.t
+++ b/t/versions.t
@@ -74,6 +74,20 @@ BEGIN {
             },
         );
     }
+
+    $INC{'My/Exporter2.pm'} = 1;
+    package My::Exporter2;
+
+    sub IMPORTER_MENU {
+        return (
+            export_anon => {
+                foo => sub { 'foo' },
+            },
+            export_versions => {
+                root_name => 'my_root_ver',
+            },
+        );
+    }
 }
 
 {
@@ -115,17 +129,22 @@ BEGIN {
     ::ok(!__PACKAGE__->can('d'), "Did not import d()");
 }
 
+{
+    package My::Importer::D;
+    Importer->import('My::Exporter2', '+my_root_ver', 'foo');
+    ::can_ok(__PACKAGE__, 'foo');
+}
 
 $main::ON_USE = 1;
 {
     package My::On::Use::A;
     Importer->import('My::Exporter');
     ::can_ok(__PACKAGE__, 'x');
-    ::is($main::USED{v0}, 1, "noted that we used v0");
+    ::is($main::USED{'<NO VERSION SPECIFIED>'}, 1, "noted that we used v0");
 
     package My::On::Use::B;
     Importer->import('My::Exporter');
-    ::is($main::USED{v0}, 2, "noted that we used v0 again");
+    ::is($main::USED{'<NO VERSION SPECIFIED>'}, 2, "noted that we used v0 again");
 
     package My::On::Use::C;
     Importer->import('My::Exporter', ':v1');