NAME Regexp::Common::comment -- provide regexes for comments. SYNOPSIS use Regexp::Common qw /comment/; while (<>) { /$RE{comment}{C}/ and print "Contains a C comment\n"; /$RE{comment}{C++}/ and print "Contains a C++ comment\n"; /$RE{comment}{PHP}/ and print "Contains a PHP comment\n"; /$RE{comment}{Java}/ and print "Contains a Java comment\n"; /$RE{comment}{Perl}/ and print "Contains a Perl comment\n"; /$RE{comment}{awk}/ and print "Contains an awk comment\n"; /$RE{comment}{HTML}/ and print "Contains an HTML comment\n"; } use Regexp::Common qw /comment RE_comment_HTML/; while (<>) { $_ =~ RE_comment_HTML() and print "Contains an HTML comment\n"; } DESCRIPTION Please consult the manual of Regexp::Common for a general description of the works of this interface. Do not use this module directly, but load it via *Regexp::Common*. This modules gives you regular expressions for comments in various languages. THE LANGUAGES Below, the comments of each of the languages are described. The patterns are available as $RE{comment}{*LANG*}, foreach language *LANG*. Some languages have variants; it's described at the individual languages how to get the patterns for the variants. Unless mentioned otherwise, "{-keep}" sets $1, $2, $3 and $4 to the entire comment, the opening marker, the content of the comment, and the closing marker (for many languages, the latter is a newline) respectively. ABC Comments in *ABC* start with a backslash ("\"), and last till the end of the line. See <http://homepages.cwi.nl/%7Esteven/abc/>. Ada Comments in *Ada* start with "--", and last till the end of the line. Advisor *Advisor* is a language used by the HP product *glance*. Comments for this language start with either "#" or "//", and last till the end of the line. Advsys Comments for the *Advsys* language start with ";" and last till the end of the line. See also <http://www.wurb.com/if/devsys/12>. Alan *Alan* comments start with "--", and last till the end of the line. See also <http://w1.132.telia.com/~u13207378/alan/manual/alanTOC.html>. Algol 60 Comments in the *Algol 60* language start with the keyword "comment", and end with a ";". See <http://www.masswerk.at/algol60/report.htm>. Algol 68 In *Algol 68*, comments are either delimited by "#", or by one of the keywords "co" or "comment". The keywords should not be part of another word. See <http://westein.arb-phys.uni-dortmund.de/~wb/a68s.txt>. With "{-keep}", only $1 will be set, returning the entire comment. ALPACA The *ALPACA* language has comments starting with "/*" and ending with "*/". awk The *awk* programming language uses comments that start with "#" and end at the end of the line. B The *B* language has comments starting with "/*" and ending with "*/". BASIC There are various forms of BASIC around. Currently, we only support the variant supported by *mvEnterprise*, whose pattern is available as $RE{comment}{BASIC}{mvEnterprise}. Comments in this language start with a "!", a "*" or the keyword "REM", and end till the end of the line. See <http://www.rainingdata.com/products/beta/docs/mve/50/ReferenceManua l/Basic.pdf>. Beatnik The esotoric language *Beatnik* only uses words consisting of letters. Words are scored according to the rules of Scrabble. Words scoring less than 5 points, or 18 points or more are considered comments (although the compiler might mock at you if you score less than 5 points). Regardless whether "{-keep}", $1 will be set, and set to the entire comment. This pattern requires *perl 5.8.0* or newer. beta-Juliet The *beta-Juliet* programming language has comments that start with "//" and that continue till the end of the line. See also <http://www.catseye.mb.ca/esoteric/b-juliet/index.html>. Befunge-98 The esotoric language *Befunge-98* uses comments that start and end with a ";". See <http://www.catseye.mb.ca/esoteric/befunge/98/spec98.html>. BML *BML*, or *Better Markup Language* is an HTML templating language that uses comments starting with "<?c_", and ending with "c_?>". See <http://www.livejournal.com/doc/server/bml.index.html>. Brainfuck The minimal language *Brainfuck* uses only eight characters, "<", ">", "[", "]", "+", "-", "." and ",". Any other characters are considered comments. With "{-keep}", $1 is set to the entire comment. C The *C* language has comments starting with "/*" and ending with "*/". C-- The *C--* language has comments starting with "/*" and ending with "*/". See <http://cs.uas.arizona.edu/classes/453/programs/C--Spec.html>. C++ The *C++* language has two forms of comments. Comments that start with "//" and last till the end of the line, and comments that start with "/*", and end with "*/". If "{-keep}" is used, only $1 will be set, and set to the entire comment. C# The *C#* language has two forms of comments. Comments that start with "//" and last till the end of the line, and comments that start with "/*", and end with "*/". If "{-keep}" is used, only $1 will be set, and set to the entire comment. See <http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cs spec/html/vclrfcsharpspec_C.asp>. Caml Comments in *Caml* start with "(*", end with "*)", and can be nested. See <http://www.cs.caltech.edu/courses/cs134/cs134b/book.pdf> and <http://pauillac.inria.fr/caml/index-eng.html>. Cg The *Cg* language has two forms of comments. Comments that start with "//" and last till the end of the line, and comments that start with "/*", and end with "*/". If "{-keep}" is used, only $1 will be set, and set to the entire comment. See <http://developer.nvidia.com/attach/3722>. CLU In "CLU", a comment starts with a procent sign ("%"), and ends with the next newline. See <ftp://ftp.lcs.mit.edu:/pub/pclu/CLU-syntax.ps> and <http://www.pmg.lcs.mit.edu/CLU.html>. COBOL Traditionally, comments in *COBOL* are indicated by an asteriks in the seventh column. This is what the pattern matches. Modern compiler may more lenient though. See <http://www.csis.ul.ie/cobol/Course/COBOLIntro.htm>, and <http://www.csis.ul.ie/cobol/default.htm>. CQL Comments in the chess query language (*CQL*) start with a semi colon (";") and last till the end of the line. See <http://www.rbnn.com/cql/>. Crystal Report The formula editor in *Crystal Reports* uses comments that start with "//", and end with the end of the line. Dylan There are two types of comments in *Dylan*. They either start with "//", or are nested comments, delimited with "/*" and "*/". Under "{-keep}", only $1 will be set, returning the entire comment. This pattern requires *perl 5.6.0* or newer. ECMAScript The *ECMAScript* language has two forms of comments. Comments that start with "//" and last till the end of the line, and comments that start with "/*", and end with "*/". If "{-keep}" is used, only $1 will be set, and set to the entire comment. *JavaScript* is Netscapes implementation of *ECMAScript*. See <http://www.ecma-international.org/publications/files/ecma-st/Ecma-2 62.pdf>, and <http://www.ecma-international.org/publications/standards/Ecma-262.h tm>. Eiffel *Eiffel* comments start with "--", and last till the end of the line. False In *False*, comments start with "{" and end with "}". See <http://wouter.fov120.com/false/false.txt> FPL The *FPL* language has two forms of comments. Comments that start with "//" and last till the end of the line, and comments that start with "/*", and end with "*/". If "{-keep}" is used, only $1 will be set, and set to the entire comment. Forth Comments in Forth start with "\", and end with the end of the line. See also <http://docs.sun.com/sb/doc/806-1377-10>. Fortran There are two forms of *Fortran*. There's free form *Fortran*, which has comments that start with "!", and end at the end of the line. The pattern for this is given by $RE{Fortran}. Fixed form *Fortran*, which has been obsoleted, has comments that start with "C", "c" or "*" in the first column, or with "!" anywhere, but the sixth column. The pattern for this are given by $RE{Fortran}{fixed}. See also <http://www.cray.com/craydoc/manuals/007-3692-005/html-007-3692-005/ >. Funge-98 The esotoric language *Funge-98* uses comments that start and end with a ";". fvwm2 Configuration files for *fvwm2* have comments starting with a "#" and lasting the rest of the line. Haifu *Haifu*, an esotoric language using haikus, has comments starting and ending with a ",". See <http://www.dangermouse.net/esoteric/haifu.html>. Haskell There are two types of comments in *Haskell*. They either start with at least two dashes, or are nested comments, delimited with "{-" and "-}". Under "{-keep}", only $1 will be set, returning the entire comment. This pattern requires *perl 5.6.0* or newer. HTML In *HTML*, comments only appear inside a *comment declaration*. A comment declaration starts with a "<!", and ends with a ">". Inside this declaration, we have zero or more comments. Comments starts with "--" and end with "--", and are optionally followed by whitespace. The pattern $RE{comment}{HTML} recognizes those comment declarations (and hence more than a comment). Note that this is not the same as something that starts with "<!--" and ends with "-->", because the following will be matched completely: <!-- First Comment -- --> Second Comment <!-- -- Third Comment --> Do not be fooled by what your favourite browser thinks is an HTML comment. If "{-keep}" is used, the following are returned: $1 captures the entire comment declaration. $2 captures the MDO (markup declaration open), "<!". $3 captures the content between the MDO and the MDC. $4 captures the (last) comment, without the surrounding dashes. $5 captures the MDC (markup declaration close), ">". Hugo There are two types of comments in *Hugo*. They either start with "!" (which cannot be followed by a "\"), or are nested comments, delimited with "!\" and "\!". Under "{-keep}", only $1 will be set, returning the entire comment. This pattern requires *perl 5.6.0* or newer. Icon *Icon* has comments that start with "#" and end at the next new line. See <http://www.toolsofcomputing.com/IconHandbook/IconHandbook.pdf>, <http://www.cs.arizona.edu/icon/index.htm>, and <http://burks.bton.ac.uk/burks/language/icon/index.htm>. ILLGOL The esotoric language *ILLGOL* uses comments starting with *NB* and lasting till the end of the line. See <http://www.catseye.mb.ca/esoteric/illgol/index.html>. INTERCAL Comments in INTERCAL are single line comments. They start with one of the keywords "NOT" or "N'T", and can optionally be preceded by the keywords "DO" and "PLEASE". If both keywords are used, "PLEASE" precedes "DO". Keywords are separated by whitespace. J The language *J* uses comments that start with "NB.", and that last till the end of the line. See <http://www.jsoftware.com/books/help/primer/contents.htm>, and <http://www.jsoftware.com/>. Java The *Java* language has two forms of comments. Comments that start with "//" and last till the end of the line, and comments that start with "/*", and end with "*/". If "{-keep}" is used, only $1 will be set, and set to the entire comment. JavaDoc The *Javadoc* documentation syntax is demarked with a subset of ordinary Java comments to separate it from code. Comments start with "/**" end with "*/". If "{-keep}" is used, only $1 will be set, and set to the entire comment. See <http://www.oracle.com/technetwork/java/javase/documentation/index-1 37868.html#format>. JavaScript The *JavaScript* language has two forms of comments. Comments that start with "//" and last till the end of the line, and comments that start with "/*", and end with "*/". If "{-keep}" is used, only $1 will be set, and set to the entire comment. *JavaScript* is Netscapes implementation of *ECMAScript*. See <http://www.mozilla.org/js/language/E262-3.pdf>, and <http://www.mozilla.org/js/language/>. LaTeX The documentation language *LaTeX* uses comments starting with "%" and ending at the end of the line. Lisp Comments in *Lisp* start with a semi-colon (";") and last till the end of the line. LPC The *LPC* language has comments starting with "/*" and ending with "*/". LOGO Comments for the language *LOGO* start with ";", and last till the end of the line. lua Comments for the *lua* language start with "--", and last till the end of the line. See also <http://www.lua.org/manual/manual.html>. M, MUMPS In "M" (aka "MUMPS"), comments start with a semi-colon, and last till the end of a line. The language specification requires the semi-colon to be preceded by one or more *linestart character*s. Those characters default to a space, but that's configurable. This requirement, of preceding the comment with linestart characters is not tested for. See <ftp://ftp.intersys.com/pub/openm/ism/ism64docs.zip>, <http://mtechnology.intersys.com/mproducts/openm/index.html>, and <http://mcenter.com/mtrc/index.html>. m4 By default, the preprocessor language *m4* uses single line comments, that start with a "#" and continue to the end of the line, including the newline. The pattern "$RE {comment} {m4}" matches such comments. In *m4*, it is possible to change the starting token though. See <http://wolfram.schneider.org/bsd/7thEdManVol2/m4/m4.pdf>, <http://www.cs.stir.ac.uk/~kjt/research/pdf/expl-m4.pdf>, and <http://www.gnu.org/software/m4/manual/>. Modula-2 In "Modula-2", comments start with "(*", and end with "*)". Comments may be nested. See <http://www.modula2.org/>. Modula-3 In "Modula-3", comments start with "(*", and end with "*)". Comments may be nested. See <http://www.m3.org/>. mutt Configuration files for *mutt* have comments starting with a "#" and lasting the rest of the line. Nickle The *Nickle* language has one line comments starting with "#" (like Perl), or multiline comments delimited by "/*" and "*/" (like C). Under "-keep", only $1 will be set. See also <http://www.nickle.org>. Oberon Comments in *Oberon* start with "(*" and end with "*)". See <http://www.oberon.ethz.ch/oreport.html>. Pascal There are many implementations of Pascal. This modules provides pattern for comments of several implementations. $RE{comment}{Pascal} This is the pattern that recognizes comments according to the Pascal ISO standard. This standard says that comments start with either "{", or "(*", and end with "}" or "*)". This means that "{*)" and "(*}" are considered to be comments. Many Pascal applications don't allow this. See <http://www.pascal-central.com/docs/iso10206.txt> $RE{comment}{Pascal}{Alice} The *Alice Pascal* compiler accepts comments that start with "{" and end with "}". Comments are not allowed to contain newlines. See <http://www.templetons.com/brad/alice/language/>. $RE{comment}{Pascal}{Delphi}, $RE{comment}{Pascal}{Free} and $RE{comment}{Pascal}{GPC} The *Delphi Pascal*, *Free Pascal* and the *Gnu Pascal Compiler* implementations of Pascal all have comments that either start with "//" and last till the end of the line, are delimited with "{" and "}" or are delimited with "(*" and "*)". Patterns for those comments are given by $RE{comment}{Pascal}{Delphi}, $RE{comment}{Pascal}{Free} and $RE{comment}{Pascal}{GPC} respectively. These patterns only set $1 when "{-keep}" is used, which will then include the entire comment. See <http://info.borland.com/techpubs/delphi5/oplg/>, <http://www.freepascal.org/docs-html/ref/ref.html> and <http://www.gnu-pascal.de/gpc/>. $RE{comment}{Pascal}{Workshop} The *Workshop Pascal* compiler, from SUN Microsystems, allows comments that are delimited with either "{" and "}", delimited with "(*)" and "*"), delimited with "/*", and "*/", or starting and ending with a double quote ("""). When "{-keep}" is used, only $1 is set, and returns the entire comment. See <http://docs.sun.com/db/doc/802-5762>. PEARL Comments in *PEARL* start with a "!" and last till the end of the line, or start with "/*" and end with "*/". With "{-keep}", $1 will be set to the entire comment. PHP Comments in *PHP* start with either "#" or "//" and last till the end of the line, or are delimited by "/*" and "*/". With "{-keep}", $1 will be set to the entire comment. PL/B In *PL/B*, comments start with either "." or ";", and end with the next newline. See <http://www.mmcctech.com/pl-b/plb-0010.htm>. PL/I The *PL/I* language has comments starting with "/*" and ending with "*/". PL/SQL In *PL/SQL*, comments either start with "--" and run till the end of the line, or start with "/*" and end with "*/". Perl *Perl* uses comments that start with a "#", and continue till the end of the line. Portia The *Portia* programming language has comments that start with "//", and last till the end of the line. Python *Python* uses comments that start with a "#", and continue till the end of the line. Q-BAL Comments in the *Q-BAL* language start with "`" (a backtick), and contine till the end of the line. QML In "QML", comments start with "#" and last till the end of the line. See <http://www.questionmark.com/uk/qml/overview.doc>. R The statistical language *R* uses comments that start with a "#" and end with the following new line. See <http://www.r-project.org/>. REBOL Comments for the *REBOL* language start with ";" and last till the end of the line. Ruby Comments in *Ruby* start with "#" and last till the end of the time. Scheme *Scheme* comments start with ";", and last till the end of the line. See <http://schemers.org/>. shell Comments in various *shell*s start with a "#" and end at the end of the line. Shelta The esotoric language *Shelta* uses comments that start and end with a ";". See <http://www.catseye.mb.ca/esoteric/shelta/index.html>. SLIDE The *SLIDE* language has two froms of comments. First there is the line comment, which starts with a "#" and includes the rest of the line (just like Perl). Second, there is the multiline, nested comment, which are delimited by "(*" and "*)". Under C{-keep}>, only $1 is set, and is set to the entire comment. See <http://www.cs.berkeley.edu/~ug/slide/docs/slide/spec/spec_frame_int ro.shtml>. slrn Configuration files for *slrn* have comments starting with a "%" and lasting the rest of the line. Smalltalk *Smalltalk* uses comments that start and end with a double quote, """. SMITH Comments in the *SMITH* language start with ";", and last till the end of the line. Squeak In the Smalltalk variant *Squeak*, comments start and end with """. Double quotes can appear inside comments by doubling them. SQL Standard *SQL* uses comments starting with two or more dashes, and ending at the end of the line. *MySQL* does not follow the standard. Instead, it allows comments that start with a "#" or "-- " (that's two dashes and a space) ending with the following newline, and comments starting with "/*", and ending with the next ";" or "*/" that isn't inside single or double quotes. A pattern for this is returned by $RE{comment}{SQL}{MySQL}. With "{-keep}", only $1 will be set, and it returns the entire comment. Tcl In *Tcl*, comments start with "#" and continue till the end of the line. TeX The documentation language *TeX* uses comments starting with "%" and ending at the end of the line. troff The document formatting language *troff* uses comments starting with "\"", and continuing till the end of the line. Ubercode The Windows programming language *Ubercode* uses comments that start with "//" and continue to the end of the line. See <http://www.ubercode.com>. vi In configuration files for the editor *vi*, one can use comments starting with """, and ending at the end of the line. *W In the language **W*, comments start with "||", and end with "!!". zonefile Comments in DNS *zonefile*s start with ";", and continue till the end of the line. ZZT-OOP The in-game language *ZZT-OOP* uses comments that start with a "'" character, and end at the following newline. See <http://dave2.rocketjump.org/rad/zzthelp/lang.html>. REFERENCES [Go 90] Charles F. Goldfarb: *The SGML Handbook*. Oxford: Oxford University Press. 1990. ISBN 0-19-853737-9. Ch. 10.3, pp 390-391. SEE ALSO Regexp::Common for a general description of how to use this interface. AUTHOR Damian Conway (damian AT conway.org) MAINTENANCE This package is maintained by Abigail (*regexp-common AT abigail.be*). BUGS AND IRRITATIONS Bound to be plenty. For a start, there are many common regexes missing. Send them in to *regexp-common AT abigail.be*. LICENSE and COPYRIGHT This software is Copyright (c) 2001 - 2017, Damian Conway and Abigail. This module is free software, and maybe used under any of the following licenses: 1) The Perl Artistic License. See the file COPYRIGHT.AL. 2) The Perl Artistic License 2.0. See the file COPYRIGHT.AL2. 3) The BSD License. See the file COPYRIGHT.BSD. 4) The MIT License. See the file COPYRIGHT.MIT.
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