NAME

Acme::Comment

SYNOPSIS

    use Acme::Comment type=>'C++', own_line=>1;

    /*
    if (ref $mod) {
        $bar->{do}->blat(msg => 'blarg');
        eval {

    i'm sooo sick of this time for some coffee

    */

    // I prefer beer.  --sqrn

DESCRIPTION

Acme::Comment allows multi-line comments which are filtered out. Unlike the pseudo multi-line comment if (0) {}, the code being commented out need not be syntactically valid.

USE

Acme::Comment contains several different commenting styles.

Styles may be specified by the types argument, or by start and end and manipulated with own_line and one_line.

Styles may contain multi-line comments and single-line comments. Perl, for example, has single-line comments in the form of #.

C, on the other hand, has multi-line comments which begin with /* and end with */.

With multi-line comments, leaving out a begin or an end comment will cause an error.

Both types of comments may only be preceded on a line by whitespace.

own_line

By default, own_line is true, which means that multi-line comments may not be followed by any characters other than whitespace on the same line. This is the safest option if you think your code may contain the comment characters (perhaps in a regex). If you disable it, other characters are allowed on the line after the starting delimiter, but these characters will be ignored. The closing delimiter cannot be followed by any other characters.

Thus, in the following example, $foo would be set to 1.

    /* This is my real comment.
    */
    $foo = 1;

If you wish to change this option, you must specify either a type or start and end.

one_line

By default, this is set to false, which means that multi-line comments may not end on the same line in which they begin. Turning this on allows the following syntax:

    /* comment */

If you wish to change this option, you must specify either a type or start and end.

start and end

The start and end arguments allow you to supply your own commenting pattern instead of one of the ones available with type. It is not valid to provide the same pattern for both start and end.

You cannot specify both type and start and end, and start and end must both be provided if you provide one of them.

types

The types argument specifies what language style should be used. Only one language style may be specified.

• Ada

  Single-line comments begin with '.

• Advsys

  Advsys single-line comments begin with ;.

• Alan

  Single-line comments start with --.

• Algol

  Multi-line comments begin with 'comment' and end with ;.

  NOTE: You should not use Algol with own_line set to 0: The source filter will take a ; to be an ending tag for your comments, regardless of where it is.

• AWK

  Single-line comments use #.

• B

  Multi-line comments use /* and */.

• Basic

  Single-line comments begin with '.

• Beta

  Multi-line comments use (* and *).

• Bliss

  Multi-line comments use (* and *).

• Blue

  Single-line comments use either == or --.

• C

  The default for Acme::Comment is C-style multi-line commenting with /* and */. However, if you wish to change one_line or own_line, you must explicitly specify the type.

• C++

  C++ multi-line style uses /* and */. Single-line uses //.

• C#

  C# multi-line style uses /* and */. Single-line uses //.

• Chill

  Multi-line comments use /* and */.

• Clean

  Clean multi-line style uses /* and */. Single-line uses //.

• E

  Single-line comments use #.

• Eiffel

  Single-line comments start with --.

• Elastic

  Elastic multi-line style uses /* and */. Single-line uses //.

• Focal

  Single-line comments start with comment.

• Fortran

  Single-line comments use !.

• Guile

  Guile multi-line style uses /* and */. Single-line uses //.

• Haskell

  Single-line comments start with --.

• HTML

  HTML style has multi-line commenting in the form of <!-- and -->.

• Hugo

  Multi-line comments begin with !\ and end with \!. Single-line comments are not implemented due to their similarity with multi-line comments.

• Icon

  Single-line comments use #.

• Intercal

  Single-line comments are marked with DO NOTE THAT and may optionally be preceded by a line number in the following syntax: (23) DO NOTE THAT.

• Java

  Java multi-line style uses /* and */. Single-line uses //.

• Joy

  Multi-line comments use (* and *).

• LaTeX

  Single-line comments use %.

• LISP

  LISP single-line comments begin with ;.

• Orthogonal

  Orthogonal single-line comments begin with ;.

• Parrot

  Single-line comments use #.

• Pascal

  Multi-line comments use (* and *).

• Perl

  Single-line comments use #.

• PHP

  PHP multi-line style uses /* and */. Single-line uses //.

• Pilot

  Single-line comments in the syntax \/\/ are supported.

• PL/I

  Multi-line comments use /* and */.

• PostScript

  Single-line comments use %.

• Python

  Single-line comments use #.

• Ruby

  Ruby multi-line comments begin with =begin and end with =end. Single-line comments use #.

• Scheme

  Scheme single-line comments begin with ;.

• Unlambda

  Single-line comments use #.

• Var'aq

  Multi-line comments use (* and *).

CAVEATS

Because of the way source filters work, it is not possible to eval code containing comments and have them correctly removed.

NOTE

Some of these programming languages may be spelled incorrectly, or may have the wrong quote characters noted. The majority of this information was found by searches for language specifications.

So please report errors, as well as obscure commenting syntax you know of.

Acknowledgements

Thanks to Abigail and Glenn Maciag for their suggestions.

BUG REPORTS

Please report bugs or other issues to <bug-acme-comment@rt.cpan.org>.

AUTHOR

This module by Jos Boumans <kane@cpan.org>.

COPYRIGHT

This library is free software; you may redistribute and/or modify it under the same terms as Perl itself.