File Coverage

blib/lib/Regexp/Common/comment.pm

Criterion	Covered	Total	%
statement	52	52	100.0
branch	8	8	100.0
condition			n/a
subroutine	12	12	100.0
pod	0	5	0.0
total	72	77	93.5

package Regexp::Common::comment;

use 5.10.0;

use strict;
use warnings;
no  warnings 'syntax';

use Regexp::Common qw /pattern clean no_defaults/;

our $VERSION = '2017060201';

my @generic = (
    {languages => [qw /ABC Forth/],
     to_eol    => ['\\\\']},   # This is for just a *single* backslash.

    {languages => [qw /Ada Alan Eiffel lua/],
     to_eol    => ['--']},

    {languages => [qw /Advisor/],
     to_eol    => ['#|//']},

    {languages => [qw /Advsys CQL Lisp LOGO M MUMPS REBOL Scheme
                       SMITH zonefile/],
     to_eol    => [';']},

    {languages => ['Algol 60'],
     from_to   => [[qw /comment ;/]]},

    {languages => [qw {ALPACA B C C-- LPC PL/I}],
     from_to   => [[qw {/* */}]]},

    {languages => [qw /awk fvwm2 Icon m4 mutt Perl Python QML
                       R Ruby shell Tcl/],
     to_eol    => ['#']},

    {languages => [[BASIC => 'mvEnterprise']],
     to_eol    => ['[*!]|REM']},

    {languages => [qw /Befunge-98 Funge-98 Shelta/],
     id        => [';']},

    {languages => ['beta-Juliet', 'Crystal Report', 'Portia', 'Ubercode'],
     to_eol    => ['//']},

    {languages => ['BML'],
     from_to   => [['']],
    },

    {languages => [qw /C++/, 'C#', qw /Cg ECMAScript FPL Java JavaScript/],
     to_eol    => ['//'],
     from_to   => [[qw {/* */}]]},

    {languages => [qw /CLU LaTeX slrn TeX/],
     to_eol    => ['%']},

    {languages => [qw /False/],
     from_to   => [[qw !{ }!]]},

    {languages => [qw /Fortran/],
     to_eol    => ['!']},

    {languages => [qw /Haifu/],
     id        => [',']},

    {languages => [qw /ILLGOL/],
     to_eol    => ['NB']},

    {languages => [qw /INTERCAL/],
     to_eol    => [q{(?:(?:PLEASE(?:\s+DO)?|DO)\s+)?(?:NOT|N'T)}]},

    {languages => [qw /J/],
     to_eol    => ['NB[.]']},

    {languages => [qw /JavaDoc/],
     from_to   => [[qw {/** */}]]},

    {languages => [qw /Nickle/],
     to_eol    => ['#'],
     from_to   => [[qw {/* */}]]},

    {languages => [qw /Oberon/],
     from_to   => [[qw /(* *)/]]},

    {languages => [[qw /Pascal Delphi/], [qw /Pascal Free/], [qw /Pascal GPC/]],
     to_eol    => ['//'],
     from_to   => [[qw !{ }!], [qw !(* *)!]]},

    {languages => [[qw /Pascal Workshop/]],
     id        => [qw /"/],
     from_to   => [[qw !{ }!], [qw !(* *)!], [qw !/* */!]]},

    {languages => [qw /PEARL/],
     to_eol    => ['!'],
     from_to   => [[qw {/* */}]]},

    {languages => [qw /PHP/],
     to_eol    => ['#', '//'],
     from_to   => [[qw {/* */}]]},

    {languages => [qw !PL/B!],
     to_eol    => ['[.;]']},

    {languages => [qw !PL/SQL!],
     to_eol    => ['--'],
     from_to   => [[qw {/* */}]]},

    {languages => [qw /Q-BAL/],
     to_eol    => ['`']},

    {languages => [qw /Smalltalk/],
     id        => ['"']},

    {languages => [qw /SQL/],
     to_eol    => ['-{2,}']},

    {languages => [qw /troff/],
     to_eol    => ['\\\"']},

    {languages => [qw /vi/],
     to_eol    => ['"']},

    {languages => [qw /*W/],
     from_to   => [[qw {|| !!}]]},

    {languages => [qw /ZZT-OOP/],
     to_eol    => ["'"]},
);

my @plain_or_nested = (
   [Caml         =>  undef,       "(*"  => "*)"],
   [Dylan        =>  "//",        "/*"  => "*/"],
   [Haskell      =>  "-{2,}",     "{-"  => "-}"],
   [Hugo         =>  "!(?!\\\\)", "!\\" => "\\!"],
   [SLIDE        =>  "#",         "(*"  => "*)"],
  ['Modula-2'    =>  undef,       "(*"  => "*)"],
  ['Modula-3'    =>  undef,       "(*"  => "*)"],
);

#
# Helper subs.
#

sub combine      {
    local $_ = join "|", @_;
    if (@_ > 1) {
        s/\(\?k:/(?:/g;
        $_ = "(?k:$_)";
    }
    $_
}

sub to_eol  ($)  {"(?k:(?k:$_[0])(?k:[^\\n]*)(?k:\\n))"}
sub id      ($)  {"(?k:(?k:$_[0])(?k:[^$_[0]]*)(?k:$_[0]))"}  # One char only!
sub from_to      {
    my ($begin, $end) = @_;

    my $qb  = quotemeta $begin;
    my $qe  = quotemeta $end;
    my $fe  = quotemeta substr $end   => 0, 1;
    my $te  = quotemeta substr $end   => 1;

    "(?k:(?k:$qb)(?k:(?:[^$fe]+|$fe(?!$te))*)(?k:$qe))";
}


my $count = 0;
sub nested {
    my ($begin, $end) = @_;

    $count ++;
    my $r = '(??{$Regexp::Common::comment ['. $count . ']})';

    my $qb  = quotemeta $begin;
    my $qe  = quotemeta $end;
    my $fb  = quotemeta substr $begin => 0, 1;
    my $fe  = quotemeta substr $end   => 0, 1;

    my $tb  = quotemeta substr $begin => 1;
    my $te  = quotemeta substr $end   => 1;

    use re 'eval';

    my $re;
    if ($fb eq $fe) {
        $re = qr /(?:$qb(?:(?>[^$fb]+)|$fb(?!$tb)(?!$te)|$r)*$qe)/;
    }
    else {
        local $"      =  "|";
        my   @clauses =  "(?>[^$fb$fe]+)";
        push @clauses => "$fb(?!$tb)" if length $tb;
        push @clauses => "$fe(?!$te)" if length $te;
        push @clauses =>  $r;
        $re           =   qr /(?:$qb(?:@clauses)*$qe)/;
    }

    $Regexp::Common::comment [$count] = qr/$re/;
}

#
# Process data.
#

foreach my $info (@plain_or_nested) {
    my ($language, $mark, $begin, $end) = @$info;
    pattern name    => [comment => $language],
            create  =>
                sub {my $re     = nested $begin => $end;
                     my $prefix = defined $mark ? $mark . "[^\n]*\n|" : "";
                     exists $_ [1] -> {-keep} ? qr /($prefix$re)/
                                              : qr  /$prefix$re/
                },
            ;
}


foreach my $group (@generic) {
    my $pattern = combine +(map {to_eol   $_} @{$group -> {to_eol}}),
                           (map {from_to @$_} @{$group -> {from_to}}),
                           (map {id       $_} @{$group -> {id}}),
                  ;
    foreach my $language  (@{$group -> {languages}}) {
        pattern name    => [comment => ref $language ? @$language : $language],
                create  => $pattern,
                ;
    }
}



#
# Other languages.
#

# http://www.pascal-central.com/docs/iso10206.txt
pattern name    => [qw /comment Pascal/],
        create  => '(?k:' . '(?k:[{]|[(][*])'
                          . '(?k:[^}*]*(?:[*](?![)])[^}*]*)*)'
                          . '(?k:[}]|[*][)])'
                          . ')'
        ;

# http://www.templetons.com/brad/alice/language/
pattern name    =>  [qw /comment Pascal Alice/],
        create  =>  '(?k:(?k:[{])(?k:[^}\n]*)(?k:[}]))'
        ;


# http://westein.arb-phys.uni-dortmund.de/~wb/a68s.txt
pattern name    => [qw (comment), 'Algol 68'],
        create  => q {(?k:(?:#[^#]*#)|}                           .
                   q {(?:\bco\b(?:[^c]+|\Bc|\bc(?!o\b))*\bco\b)|} .
                   q {(?:\bcomment\b(?:[^c]+|\Bc|\bc(?!omment\b))*\bcomment\b))}
        ;


# See rules 91 and 92 of ISO 8879 (SGML).
# Charles F. Goldfarb: "The SGML Handbook".
# Oxford: Oxford University Press. 1990. ISBN 0-19-853737-9.
# Ch. 10.3, pp 390.
pattern name    => [qw (comment HTML)],
        create  => q {(?k:(?k:))},
        ;


pattern name    => [qw /comment SQL MySQL/],
        create  => q {(?k:(?:#|-- )[^\n]*\n|} .
                   q {/\*(?:(?>[^*;"']+)|"[^"]*"|'[^']*'|\*(?!/))*(?:;|\*/))},
        ;

# Anything that isn't <>[]+-.,
# http://home.wxs.nl/~faase009/Ha_BF.html
pattern name    => [qw /comment Brainfuck/],
        create  => '(?k:[^<>\[\]+\-.,]+)'
        ;

# Squeak is a variant of Smalltalk-80.
# http://www.squeak.
# http://mucow.com/squeak-qref.html
pattern name    => [qw /comment Squeak/],
        create  => '(?k:(?k:")(?k:[^"]*(?:""[^"]*)*)(?k:"))'
        ;

#
# Scores of less than 5 or above 17....
# http://www.cliff.biffle.org/esoterica/beatnik.html
@Regexp::Common::comment::scores = (1,  3,  3,  2,  1,  4,  2,  4,  1,  8,
                                    5,  1,  3,  1,  1,  3, 10,  1,  1,  1,
                                    1,  4,  4,  8,  4, 10);
{
my ($s, $x);
pattern name    =>  [qw /comment Beatnik/],
        create  =>  sub {
            use re 'eval';
            my $re = qr {\b([A-Za-z]+)\b
                         (?(?{($s, $x) = (0, lc $^N);
                              $s += $Regexp::Common::comment::scores
                                    [ord (chop $x) - ord ('a')] while length $x;
                              $s  >= 5 && $s < 18})XXX|)}x;
            $re;
        },
        ;
}


# http://www.cray.com/craydoc/manuals/007-3692-005/html-007-3692-005/
#  (Goto table of contents/3.3 Source Form)
# Fortran, in fixed format. Comments start with a C, c or * in the first
# column, or a ! anywhere, but the sixth column. Then end with a newline.
pattern name    =>  [qw /comment Fortran fixed/],
        create  =>  '(?k:(?k:(?:^[Cc*]|(?
        ;


# http://www.csis.ul.ie/cobol/Course/COBOLIntro.htm
# Traditionally, comments in COBOL were indicated with an asteriks in
# the seventh column. Modern compilers may be more lenient.
pattern name    =>  [qw /comment COBOL/],
        create  =>  '(?<=^......)(?k:(?k:[*])(?k:[^\n]*)(?k:\n))',
        ;

1;


__END__