From: Vasco Almeida <vascomalmeida@sapo.pt>
Date: Wed, 09 Nov 2016 17:02:23 GMT
Subject: Re: [PATCH v5 01/16] Git.pm: add subroutines for commenting lines
Message-ID: <1478710943.28771.4.camel@sapo.pt>
In-Reply-To: <xmqqshr19oxp.fsf@gitster.mtv.corp.google.com>

A Ter, 08-11-2016 às 17:06 -0800, Junio C Hamano escreveu:
> Vasco Almeida <vascomalmeida@sapo.pt> writes:
> 
> > 
> > Add subroutines prefix_lines and comment_lines.
> > 
> > Signed-off-by: Vasco Almeida <vascomalmeida@sapo.pt>
> > ---
> >  perl/Git.pm | 23 +++++++++++++++++++++++
> >  1 file changed, 23 insertions(+)
> > 
> > diff --git a/perl/Git.pm b/perl/Git.pm
> > index b2732822a..17be59fb7 100644
> > --- a/perl/Git.pm
> > +++ b/perl/Git.pm
> > @@ -1438,6 +1438,29 @@ sub END {
> >  
> >  } # %TEMP_* Lexical Context
> >  
> > +=item prefix_lines ( PREFIX, STRING )
> > +
> > +Prefixes lines in C<STRING> with C<PREFIX>.
> > +
> > +=cut
> > +
> > +sub prefix_lines {
> > +	my ($prefix, $string) = @_;
> > +	$string =~ s/^/$prefix/mg;
> > +	return $string;
> > +}
> > +
> > +=item comment_lines ( STRING )
> > +
> > +Comments lines following core.commentchar configuration.
> > +
> > +=cut
> > +
> > +sub comment_lines {
> > +	my $comment_line_char = config("core.commentchar") || '#';
> > +	return prefix_lines("$comment_line_char ", @_);
> > +}
> > +
> 
> This makes it appear as if comment_lines can take arbitrary number
> of strings as its arguments (because the outer caller just passes @_
> thru), but in fact because prefix_lines ignores anything other than
> $_[0] and $_[1], only the first parameter given to comment_lineS sub
> is inspected for lines in it and the prefix-char prefixed at the
> beginning of each of them.
> 
> Which is not a great interface, as it is quite misleading.
> 
> Perhaps
> 
> 	prefix_lines("#", join("\n", @_));
> 
> or something like that may make it less confusing.

I prefer to have like this instead

sub prefix_lines {
        my $prefix = shift;
        my $string = join("\n", @_);
        $string =~ s/^/$prefix/mg;
        return $string;
}

So both subroutines can take several strings as arguments.