address: pairs: new helper for JMAP (and maybe lei)

Per JMAP RFC 8621 sec 4.1.2.3, we should be able to
denote the lack of a phrase/comment corresponding to an
email address with a JSON "null" (or Perl `undef').

  [
    { "name": "James Smythe", "email": "james@example.com" },
    { "name": null, "email": "jane@example.com" },
    { "name": "John Smith", "email": "john@example.com" }
  ]

The new "pairs" method just returns a 2 dimensional array
and the consumer will fill in the field names if necessary
(or not).

lei(1) may use the two dimensional array as-is for JSON output.

1 files changed, 21 insertions, 0 deletions

diff --git a/lib/PublicInbox/AddressPP.pm b/lib/PublicInbox/AddressPP.pm
index c04de74b..6a3ae4fe 100644
--- a/lib/PublicInbox/AddressPP.pm
+++ b/lib/PublicInbox/AddressPP.pm
@@ -13,6 +13,7 @@ sub emails {
 }
 
 sub names {
+        # split by address and post-address comment
         my @p = split(/<?([^@<>]+)\@[\w\.\-]+>?\s*(\(.*?\))?(?:,\s*|\z)/,
                         $_[0]);
         my @ret;
@@ -35,4 +36,24 @@ sub names {
         @ret;
 }
 
+sub pairs { # for JMAP, RFC 8621 section 4.1.2.3
+        my ($s) = @_;
+        [ map {
+                my $addr = $_;
+                if ($s =~ s/\A\s*(.*?)\s*<\Q$addr\E>\s*(.*?)\s*(?:,|\z)// ||
+                    $s =~ s/\A\s*(.*?)\s*\Q$addr\E\s*(.*?)\s*(?:,|\z)//) {
+                        my ($phrase, $comment) = ($1, $2);
+                        $phrase =~ tr/\r\n\t / /s;
+                        $phrase =~ s/\A['"\s]*//;
+                        $phrase =~ s/['"\s]*\z//;
+                        $phrase =~ s/\s*<*\s*\z//;
+                        $phrase = undef if $phrase !~ /\S/;
+                        $comment = ($comment =~ /\((.*?)\)/) ? $1 : undef;
+                        [ $phrase // $comment, $addr ]
+                } else {
+                        ();
+                }
+        } emails($s) ];
+}
+
 1;