Re: [WIP-PATCH 1/2] send-email: create email parser subroutine

Samuel GROOT [off-list ref] writes:

Parsing and processing in send-email is done in the same loop.

To make the code more maintainable, we create two subroutines:
- `parse_email` to separate header and body
- `parse_header` to retrieve data from header

These routines are not specific to git send-email, nor to Git.

Does it make sense to use an external library, like
http://search.cpan.org/~rjbs/Email-Simple-2.210/lib/Email/Simple.pm ,
either by depending on it, or by copying it in Git's source tree ?

If not, I think it would be better to introduce an email parsing library
in a dedicated Perl module in perl/ in our source tree, to keep
git-send-email.perl more focused on the "send-email" logic.

+sub parse_email {
+	my @header = ();
+	my @body = ();
+	my $fh = shift;
+
+	# First unfold multiline header fields
+	while (<$fh>) {
+		last if /^\s*$/;
+		if (/^\s+\S/ and @header) {
+			chomp($header[$#header]);
+			s/^\s+/ /;
+			$header[$#header] .= $_;
+		} else {
+			push(@header, $_);
+		}
+	}
+
+	# Now unfold the message body

Why "unfold"? Don't you mean "split message body into a list of lines"?

+	while (<$fh>) {
+		push @body, $_;
+	}
+
+	return (@header, @body);
+}

Please document your functions. See e.g. perl/Git.pm for an example of
what perldoc allows you to do.

This also lacks tests. One advantage of having a clean API is that it
also makes it simpler to do unit-testing. Grep "Test::More" in t/ to see
some existing unit-tests in Perl.

+	foreach(@_) {

Style: space before (.

+		if (defined $input_format && $input_format eq 'mbox') {
+			if (/^Subject:\s+(.*)$/i) {
+				$subject = $1;
+			} elsif (/^From:\s+(.*)$/i) {
+				$from = $1;

Not sure we need thes if/elsif/ for generic headers. Email::Simple's API
seems much simpler and general: $email->header("From");

+				foreach my $addr (parse_address_line($1)) {
+					push @to, $addr;
+				}

3 lines for an array concatenation in a high-level language. It looks
like 2 more than needed ;-).

+			}
+
+		} else {

Useless blank line.

-- 
Matthieu Moy
http://www-verimag.imag.fr/~moy/