Math::BigInt v1.87 take 6

[p5sagit/p5-mst-13.2.git] / lib / feature.pm

diff --git a/lib/feature.pm b/lib/feature.pm
index ab79d69..7ffae72 100644 (file)
--- a/lib/feature.pm
+++ b/lib/feature.pm
@@ -5,20 +5,21 @@ our $VERSION = '1.10';
 # (feature name) => (internal name, used in %^H)
 my %feature = (
     switch => 'feature_switch',
-    "~~"   => "feature_~~",
     say    => "feature_say",
     err    => "feature_err",
     state  => "feature_state",
 );
 
 my %feature_bundle = (
-    "5.10.0" => [qw(switch ~~ say err state)],
+    "5.10.0" => [qw(switch say err state)],
 );
 # latest version here
 # keep it harcoded until we actually bump the version number to 5.10
 $feature_bundle{"5.10"} = $feature_bundle{"5.10.0"};
 #$feature_bundle{"5.10"} = $feature_bundle{sprintf("%vd",$^V)};
 
+$feature_bundle{"5.9.5"} = $feature_bundle{"5.10.0"};
+
 # TODO:
 # - think about versioned features (use feature switch => 2)
 
@@ -37,6 +38,8 @@ feature - Perl pragma to enable new syntactic features
        default           { say "None of the above" }
     }
 
+    use feature ':5.10'; # loads all features available in perl 5.10
+
 =head1 DESCRIPTION
 
 It is usually impossible to add new syntax to Perl without breaking
@@ -79,13 +82,6 @@ given/when construct.
 
 See L<perlsyn/"Switch statements"> for details.
 
-=head2 The '~~' feature
-
-C<use feature '~~'> tells the compiler to enable the Perl 6
-smart match C<~~> operator.
-
-See L<perlsyn/"Smart matching in detail"> for details.
-
 =head2 The 'say' feature
 
 C<use feature 'say'> tells the compiler to enable the Perl 6
@@ -114,11 +110,38 @@ It's possible to load a whole slew of features in one go, using
 a I<feature bundle>. The name of a feature bundle is prefixed with
 a colon, to distinguish it from an actual feature. At present, the
 only feature bundles are C<use feature ":5.10"> and C<use feature ":5.10.0">,
-which both are equivalent to C<use feature qw(switch ~~ say err state)>.
+which both are equivalent to C<use feature qw(switch say err state)>.
 
 In the forthcoming 5.10.X perl releases, C<use feature ":5.10"> will be
 equivalent to the latest C<use feature ":5.10.X">.
 
+=head1 IMPLICIT LOADING
+
+There are two ways to load the C<feature> pragma implicitly :
+
+=over 4
+
+=item *
+
+By using the C<-E> switch on the command-line instead of C<-e>. It enables
+all available features in the main compilation unit (that is, the one-liner.)
+
+=item *
+
+By requiring explicitly a minimal Perl version number for your program, with
+the C<use VERSION> construct, and when the version is higher than or equal to
+5.9.5. That is,
+
+    use 5.9.5;
+
+will do an implicit
+
+    use feature ':5.9.5';
+
+and so on.
+
+=back
+
 =cut
 
 sub import {
@@ -128,11 +151,12 @@ sub import {
     }
     while (@_) {
        my $name = shift(@_);
-       if ($name =~ /^:(.*)/) {
-           if (!exists $feature_bundle{$1}) {
-               unknown_feature_bundle($1);
+       if (substr($name, 0, 1) eq ":") {
+           my $v = substr($name, 1);
+           if (!exists $feature_bundle{$v}) {
+               unknown_feature_bundle($v);
            }
-           unshift @_, @{$feature_bundle{$1}};
+           unshift @_, @{$feature_bundle{$v}};
            next;
        }
        if (!exists $feature{$name}) {
@@ -153,11 +177,12 @@ sub unimport {
 
     while (@_) {
        my $name = shift;
-       if ($name =~ /^:(.*)/) {
-           if (!exists $feature_bundle{$1}) {
-               unknown_feature_bundle($1);
+       if (substr($name, 0, 1) eq ":") {
+           my $v = substr($name, 1);
+           if (!exists $feature_bundle{$v}) {
+               unknown_feature_bundle($v);
            }
-           unshift @_, @{$feature_bundle{$1}};
+           unshift @_, @{$feature_bundle{$v}};
            next;
        }
        if (!exists($feature{$name})) {