Markdown.pl extending

Question

I'm not used with perl but had the need to add a couple of features, I wish I can adopt a more perl-ish coding.

Any help is welcome.

This is to add style classes to paragraphs if strarting with !, ? and a clear: both with %

Original:

foreach (@grafs) {
    unless (defined( $g_html_blocks{$_} )) {
        $_ = _RunSpanGamut($_);
        s/^([ \t]*)/<p>/;
        $_ .= "</p>";
    }
}

Modded:

foreach (@grafs) {
    unless (defined( $g_html_blocks{$_} )) {
        $_ = _RunSpanGamut($_);
        if ( m/^[ \t]*\?/ ){
            s/^([ \t]*\?[ \t]*)/<p class="Introduction">/;
        } elsif ( m/^[ \t]*\!/ ){
            s/^([ \t]*\![ \t]*)/<p class="Important">/;
        } elsif ( m/^[ \t]*%/ ){
            s/^([ \t]*%[ \t]*)/<p style="clear: both;">/;
        } else {
            s/^([ \t]*)/<p>/;
        }
        $_ .= "</p>";
    }
}

This is to add float to images like: !<[alt](url) to get a float right (and form this the % above to clear)

if (defined($align)) {
    if ($align eq "<") {
        $result .=  " style=\"float: left; margin: 0 ${padding}px ${padding}px 0;\"";
    } else {
        $result .=  " style=\"float: right; margin: 0 0 ${padding}px ${padding}px;\"";
    }
}

Answer 1

Note that a substitution only occurs if there is a match, and then it will return the number of substitutions it makes. This means that a true value is returned if a match/substitution happens.

With that in mind, you don't need the m/.../ in addition to the substitution. You can also make use of or to achieve the short-circuiting that you had with the if ... elsif ... else ... statements.

foreach (@grafs) {
    unless (defined $g_html_blocks{$_}) {
        $_ = _RunSpanGamut($_);
        s/^([ \t]*\?[ \t]*)/<p class="Introduction">/
            or
        s/^([ \t]*\![ \t]*)/<p class="Important">/ 
            or
        s/^([ \t]*%[ \t]*)/<p style="clear: both;">/
            or
        s/^([ \t]*)/<p>/;
        $_ .= "</p>";
    }
}

For the image floating, you could use a hash instead of if ... else ...:

my %float = (
    '<' => 'float: left',
    '>' => 'float: right',
    '%' => 'clear: both'
);
if (defined $align) {
    $result .= " style=\"$float{$align}; margin: 0 ${padding}px ${padding}px 0;\"";
}

A minor point: I also removed the parens from the defined checks because they're not needed and it gives you a little more white space to reduce a little clutter.