Detect whether a file contains Pod 5 or Pod 6

Changes

@@ -1,3 +1,6 @@
+0.09
+    - Detect whether a file contains Pod 5 or Pod 6
+
 0.08 Wed Jul  1 14:14:10 GMT 2009
     - Add -i/--index to list known targets
     - Rename -v (--version) option to -V

README

@@ -5,19 +5,19 @@ SYNOPSIS
     grok <options> <target>
 
      Options:
-       -F FILE, --file=FILE         A file to read Pod 6 from
+       -F FILE, --file=FILE         A file to read Pod from
        -f FORMAT, --format=FORMAT   The output format, ansi/text/xhtml
        -h, --help                   Print this help message
        -i, --index                  Print index of things grok knows about
        -l, --only                   Only print the path to the target file
        -T, --no-pager               Send output to STDOUT without any pager
        -V, --version                Print version information
 
-     If you don't supply the -F option, you need to supply a target.
+     If you don't supply the -F or -i options, you need to supply a target.
      The following targets are recognized:
 
        * A synopsis (e.g. 's02', 's02-bits', 's32-rules')
-       * A path to a file containing Pod 6
+       * A path to a file containing Pod
 
 DESCRIPTION
     This little application is intended to be a "perldoc" for Perl 6.

TODO

@@ -4,8 +4,6 @@ Features
  * Add switch to display the raw pod output. perldoc uses -u (unformatted)
  * Add -m switch to display module's file in its entirety like perldoc
  * Think about i18n, add -L for lang code like perldoc
- * Somehow detect whether a file is Pod 5 or Pod 6. A simple test might
-   be to look for =begin (Pod 6) and =cut (Pod 5)
  * Borrow the S32 function lookup feature (grok -f FUNCTION) from
    Padre::Plugin::Perl6
 

lib/App/Grok.pm

@@ -29,27 +29,24 @@ sub run {
     my ($self) = @_;
 
     $self->get_options();
-    my ($target, $renderer);
 
     if ($opt{index}) {
         print $self->target_index();
         return;
     }
 
-    if (defined $opt{file}) {
-        ($target, $renderer) = ($opt{file}, 'App::Grok::Pod6');
-    }
-    else {
-        ($target, $renderer) = $self->find_target($ARGV[0]);
-    }
+    my $target = defined $opt{file}
+        ? $opt{file}
+        : $self->find_target($ARGV[0])
+    ;
 
     die "No matching files found for target '$target'" if !-e $target;
 
     if ($opt{only}) {
         print "$target\n";
     }
     else {
-        $self->render_file($target, $renderer);
+        $self->render_file($target);
     }
 }
 
@@ -66,7 +63,10 @@ sub get_options {
         'V|version'  => sub { print "grok $VERSION\n"; exit },
     ) or pod2usage();
 
-    die "Too few arguments\n" if !$opt{index} && !defined $opt{file} && !@ARGV;
+    if (!$opt{index} && !defined $opt{file} && !@ARGV) {
+        warn "Too few arguments\n";
+        pod2usage();
+    }
 }
 
 sub target_index {
@@ -85,15 +85,33 @@ sub target_index {
     return join("\n", @index) . "\n";
 }
 
+sub detect_source {
+    my ($self, $file) = @_;
+
+    open my $handle, '<', $file or die "Can't open $file";
+    my $contents = do { local $/; scalar <$handle> };
+    close $handle;
+
+    my ($first_pod) = $contents =~ /(^=(?!encoding)\S+)/m;
+    return if !defined $first_pod; # no Pod found
+
+    if ($first_pod =~ /^=(?:pod|head\d+|over)$/
+            || $contents =~ /^=cut\b/m) {
+        return 'App::Grok::Pod5';
+    }
+    else {
+        return 'App::Grok::Pod6';
+    }
+}
+
 sub find_target {
     my ($self, $arg) = @_;
 
-    my ($target, $renderer);
-    ($target, $renderer) = $self->find_synopsis($arg);
-    ($target, $renderer) = $self->find_file($arg) if !defined $target;
+    my $target = $self->find_synopsis($arg);
+    $target = $self->find_file($arg) if !defined $target;
 
     die "Target '$arg' not recognized\n" if !$target;
-    return ($target, $renderer);
+    return $target;
 }
 
 sub find_synopsis {
@@ -105,21 +123,15 @@ sub find_synopsis {
         my $found = first { /$syn/i } @synopses;
 
         return if !defined $found;
-
-        if ($found =~ /^S26/) {
-            return (catfile($dir, $found), 'App::Grok::Pod6');
-        }
-        else {
-            return (catfile($dir, $found), 'App::Grok::Pod5');
-        }
+        return catfile($dir, $found);
     }
     elsif (my ($section) = $syn =~ /^S32-(\S+)$/i) {
         my $S32_dir = catdir($dir, 'S32-setting-library');
         my @sections = map { (splitpath($_))[2] } glob "$S32_dir/*.pod";
         my $found = first { /$section/i } @sections;
 
         if (defined $found) {
-            return (catfile($S32_dir, $found), 'App::Grok::Pod5');
+            return catfile($S32_dir, $found);
         }
     }
 
@@ -130,12 +142,13 @@ sub find_file {
     my ($self, $file) = @_;
 
     # TODO: do a grand search
-    return ($file, 'App::Grok::Pod6');
+    return $file;
 }
 
 sub render_file {
-    my ($self, $file, $renderer) = @_;
+    my ($self, $file) = @_;
 
+    my $renderer = $self->detect_source($file);
     eval "require $renderer";
     die $@ if $@;
     my $pod = $renderer->new->render($file, $opt{format});

script/grok

@@ -16,19 +16,19 @@ grok - Perl 6 documentation reader
 B<grok> <options> <target>
 
  Options:
-   -F FILE, --file=FILE         A file to read Pod 6 from
+   -F FILE, --file=FILE         A file to read Pod from
    -f FORMAT, --format=FORMAT   The output format, ansi/text/xhtml
    -h, --help                   Print this help message
    -i, --index                  Print index of things grok knows about
    -l, --only                   Only print the path to the target file
    -T, --no-pager               Send output to STDOUT without any pager
    -V, --version                Print version information
 
- If you don't supply the -F option, you need to supply a target.
+ If you don't supply the -F or -i options, you need to supply a target.
  The following targets are recognized:
 
    * A synopsis (e.g. 's02', 's02-bits', 's32-rules')
-   * A path to a file containing Pod 6
+   * A path to a file containing Pod
 
 =head1 DESCRIPTION
 

t/03_opts/02_format.t

@@ -1,7 +1,7 @@
 use strict;
 use warnings;
 use File::Spec::Functions 'catfile';
-use Test::More tests => 6;
+use Test::More tests => 12;
 
 my $script = catfile('script', 'grok');
 
@@ -20,8 +20,6 @@ like($pod6_ansi_long, qr/\e\[/, "Pod 6 ANSI has color codes (--format)");
 isnt($pod6_text_long, $pod6_xhtml_long, "Pod 6 text and xhtml are different (--format)");
 like($pod6_xhtml_long, qr/<p>/, "Pod 6 xhtml has <p> (--format)");
 
-# TODO: uncomment these when grok learns how to detect Pod 5
-=pod
 my $pod5 = catfile('t_source', 'basic5.pod');
 my $pod5_text_short  = qx/$^X $script -F $pod5 -f text/;
 my $pod5_text_long   = qx/$^X $script -F $pod5 --format text/;
@@ -36,4 +34,3 @@ isnt($pod5_text_long, $pod5_ansi_long, "Pod 5 text and ANSI are different (--for
 like($pod5_ansi_long, qr/\e\[/, "Pod 5 ANSI has color codes (--format)");
 isnt($pod5_text_long, $pod5_xhtml_long, "Pod 5 text and xhtml are different (--format)");
 like($pod5_xhtml_long, qr/<p>/, "Pod 5 xhtml has <p> (--format)");
-=cut