Perl language syntax highlighting troubles (bug or limitation ?)

[Gilles Maisonneuve]

ok, tomorrow is another day
‘see’ you tomorrow.
have a good night.
g

[Ekopalypse]

you too - see you

[Gilles Maisonneuve]

@Ekopalypse

OK, so the

(\s*(<<)\s*("{0,1}.+"{0,1})\s*;.*?\3)

is a regex group, not a function call surrounded by parenthèses or a logical group provided by the ‘r’ keyword. My mistake.
BUT THEN, it is possible in Python to enclose an instruction such as ?\3 which means (as far as I understood what you explained to me earlier) recursive reference to a regexp named ‘3’) ??? The ‘3’ name being given in the expression regexes[(3, (255,255,255))] is that correct ? SO you can reference an expression within itself while it has not be closed yet: the last parenthese of the expression 3 is after the \3). Is that what it means ?

Python syntax is a bit complicated to me.

[Alan Kilborn]

@Gilles-Maisonneuve said:

Python syntax is a bit complicated to me

It’s not Python syntax, it’s regular expression syntax. It’s just not Perl regular expression syntax. :)

And, BTW, nobody in the history of the world, especially someone coming from a Perl background, has ever uttered the phrase you typed.

[guy038]

Hello @gilles-maisonneuve, @eko-palypse and All,

Gilles, could you verify that the two lines, below, work, with yours Red, Green and Blue colors ?

regexes[(3, (R,G,B))] = (r'(?s-i)(<<)(['"]?)(\w+?)\2\h*;.*?\3', [1])
regexes[(4, (R,G,B))] = (r'(?s-i)(<<)\h+('|")(\w+?)\2\h*;.*?\3', [1,3])

For these two regexes :

• Group 1 = << = double inferior than sign

• Group 2 = ['"]? = an optional single or double quote, for regex id 3

• Group 2 = '|" = a mandatory single or double quote ,separated from the << characters with blank characters, for regex id 4

• Group 3 = \w+? = the shortest area of word characters, after the << sign, between possible quotes
  and before a semicolon character ;, with possible blank characters, before and/or after the quote characters

Notes :

• In regex id 3, only the << string is highlighted ( Group 1 )

• In regex id 4, the << and the text between quotes are highlighted ( Groups 1 and 3 )

• I added the -i in-line modifier ( => (?s-i) leading syntax ) to be sure that the ending boundary of the block corresponds exactly with the text, between quotes ( search is sensitive to case ! )

---

So my regex (?s-i)(<<)(['"]?)(\w+?)\2\h*;.*?\3 ( id 3 ) matches any of these six cases, below :

$x=<<TEXT;
Plain text here
TEXT

$x=<<'TEXT';
Plain text here
TEXT

$x=<<"TEXT";
Plain text here
TEXT

$x=<<TEXT ;
Plain text here
TEXT

$x=<<'TEXT' ;
Plain text here
TEXT

$x=<<"TEXT" ;
Plain text here
TEXT

And my regex (?s-i)(<<)\h+('|")(\w+?)\2\h*;.*?\3 ( id 4 ) matches these 4 cases, below :

$x=<< 'TEXT';
Plain text here
TEXT

$x=<< "TEXT";
Plain text here
TEXT

$x=<< 'TEXT' ;
Plain text here
TEXT

$x=<< "TEXT" ;
Plain text here
TEXT

Best Regards,

guy038

[Gilles Maisonneuve]

@guy038

Hello Guy,

Could not make it work, sorry.

I mean:

• added (replaced original ones) in the EnhancePerlLexer.py from Ekopalypse the following lines (according to what you gave me:

  regexes[(3, (224,0,0))] = (r’(?s-i)(<<)([‘"]?)(\w+?)\2\h*;.?\3’, [1])
  regexes[(4, (0,0,224))] = (r’(?s-i)(<<)\h+('|")(\w+?)\2\h;.*?\3’, [1,3])

• saved it and restarted npp

• list itemstill have the same coloring, not working.

BUT, good news:

python console:
Traceback (most recent call last):
File "C:\Users\gm\AppData\Roaming\Notepad++\plugins\Config\PythonScript\scripts\startup.py", line 1, in <module>
    import EnhancePerlLexer
File "C:\Users\gm\AppData\Roaming\Notepad++\plugins\Config\PythonScript\scripts\EnhancePerlLexer.py", line 36
    regexes[(3, (224,0,0))] = (r'(?s-i)(<<)(['"]?)(\w+?)\2\h*;.*?\3', [1])
                                                                        ^
SyntaxError: EOL while scanning string literal
Python 2.7.15 (v2.7.15:ca079a3ea3, Apr 30 2018, 16:30:26) [MSC v.1500 64 bit (AMD64)]
Initialisation took 110ms
Ready.

Can you tell me what did I did wrong ?
(When I comment out the two lines I get back a valid coloring for the ‘q*’ syntaxes (yes, forgot to tell you, this had vanished too…)

[Gilles Maisonneuve]

@guy038

Well, I commented out the rule 3 and kept rule 4.
Same kind of error:

 regexes[(4, (0,0,224))] = (r'(?s-i)(<<)\h+('|")(\w+?)\2\h*;.*?\3', [1,3])
                                                                        ^
 SyntaxError: EOL while scanning string literal

[Gilles Maisonneuve]

if I modify the rule like:

regexes[(4, (0,0,224))] = (r'(?s-i)((<<)\h+([\'"])(\w+?)\2\h*;.*?\3)', [1,3])

I don’t get any longer a syntax error in Python BUT I get no coloring for the here doc either…

Any idea ?

[Gilles Maisonneuve]

@Alan-Kilborn

chcp 1250 >NUL: & perl -e "$var=q(Alan Kilborn est déplaisant dans sa façon de s'exprimer mais il a raison.); for my $p ('\t','\s') {print qq{\$p=$p},$var=~m/($p)déplaisant\1/x?$var:qq{n'en déplaise},qq{\n} ;};" & chcp 850 >NUL:

$p=\tn'en déplaise
$p=\sAlan Kilborn est déplaisant dans sa façon de s'exprimer mais il a raison.

[Gilles Maisonneuve]

J’ai tellement l’habitude d’utiliser $1, $2, …, qui, eux, ne fonctionnent pas dans un simple ‘match’ mais uniquement dans un ‘substitute’, que je ne connaissais pas cette façon de répéter les ‘patterns’ de ‘matching’. J’ai appris quelque chose.
Dont acte.

[Ekopalypse]

@Gilles-Maisonneuve

Lunch break :-)

First, I’m sorry not to telling you that the single quote has to be escaped as it was
used to denote a python string - good, you figured it already out.

Let me break down the parts of that python code

regexes = OrderedDict()
regexes[(3, (255,0,0))] = (r'(?s)(\s*(<<)\s*("{0,1}.+"{0,1})\s*;.*?\3)', [0])

regexes is variable, containing an OrderedDict class instance.
OrderedDict is more or less the same as a perl associative array or hash

regexes[] is the python way to access a key in that hash, like in perl regexes{}
regexes[()] the round bracket denotes a python tuple, in perl a list I guess (immutable)
the python tuple contains the items 3 and (255,0,0) <- this is again a tuple
The number 3 is here to create an unique key - has nothing to do with the regex itself.
So, regexes[(3, (255,0,0))] means, get me the value for key (3, (255,0,0)) from dict(hash) regexes

The value is (r’(?s)(\s*(<<)\s*(“{0,1}.+”{0,1})\s*;.*?\3)‘, [0])
Again, a python tuple containing the items r’…’ (raw string) and a list [] (in perl an array = mutable)
Everything within the raw string is the regex to be searched for and the list contains the information
which match group should be used for coloring
[0] is always the overall match of the complete regex and [1] would be the result from group 1,
[2] from group 2 and [1,2] from group 1 and group 2

So, in terms of regular expressions only the value part of the regexes hash/dict is of interest.
For searching only the raw string and for coloring which part was defined in the list [].

Does this makes sense to you?

The reason why this regex

regexes[(4, (0,0,224))] = (r'(?s-i)((<<)\h+([\'"])(\w+?)\2\h*;.*?\3)', [1,3])

doesn’t do what you want is that you use 4 groups now whereas @guy038 has
removed the outer matching group brackets.

(?s-i)(<<)(['"]?)(\w+?)\2\h*;.*?\3

In order to make it work either use

regexes[(4, (0,0,224))] = (r'(?s-i)(<<)\h+([\'"])(\w+?)\2\h*;.*?\3', [1,3])
or
regexes[(4, (0,0,224))] = (r'(?s-i)((<<)\h+([\'"])(\w+?)\3\h*;.*?\4)', [1,3])

[Alan Kilborn]

No idea what the “chcp 1250…” posting was supposed to be saying to me. :)

This thread gets my vote for the biggest jumbled mess in the history of the community. :)

[Meta Chuh]

maybe @Ekopalypse will write a resuming manual, once this is over … i refuse :)

[Ekopalypse]

You mean a short manager summary I guess :-D

[Meta Chuh]

if a short manager summary is, in your eyes, a fully featured guide, covering all eventualities, based on all caveats of the whole topic … then yes 😉

[Ekopalypse]

LOL - back to business

[Gilles Maisonneuve]

@Ekopalypse
Replying at the message “Lunch break…” with all the explainations.

1. THANK YOU ! I start enjoying Python since I read you.
   Well, I’ll never be a disciple, because not fan of OO and have difficulty to accept a language where the tabulations and spaces define the code syntax… reminds me too much of my youth with the punch cards and the punched paper roll (and yes, I’m that old), but it’s kind of fun to read when one understand it better.
   Your analogies with Perl made it very comprehensible, very kind of you.

2. ** Y Y Y Y E E E E S S S S ! ! ! ! ! ! **
   It works. I just changed a ‘+’ into a ‘*’ after the first ‘\h’ to allow for no horizontal space between the preceding keyword / Perl-separator and the here doc starter (‘<<’). So my (yours with my ridiculous pinch of salt) regexp is now:

   regexes[(4, (0,0,224))] = (r’(?s-i)((<<)\h*([‘"])(\w+?)\3\h*;.*?\4)’, [1,3])
   ^^

Thank to you and your patience (and for the readers, pissed at my garbage, this includes you Alan, and BTW ignore my perl joke, I was upset by the tone you used and perhaps, even further by the fact that you were right [chcp needed to get the accents on the French vowels on a Windows Perl console]).

I was without-a-clue and you saved my day. And now…

Already several adventures have begun to take shape which can be solved by no-one else. Right, Eko ?
Right you are, Meta Chuh.
And so, without further ado… …I hereby declare this case… …closed.

{to sum up the solution provided by Ekopalypse in this thread of discussion}:

regexes[(1, (255,0,128))] = (r'\bq[rwqx]{0,1}\b([^\h]).*?\1|(\bq[rwqx]{0,1}\b\h+(\w).*?\3)', [0])
regexes[(2, (255,0,128))] = (r'\bq[rwqx]{0,1}\b\h*(\(.+?\)|\[.+?\]|\{.+?\})', [0])
regexes[(4, (0,112,112))] = (r'(?s-i)((<<)\h*([\'"])(\w+?)\3\h*;.*?\4)', [1,3])

Allow you to colorize your Perl ‘q*’ keywords and args with color RGB 255,0,128 and your here-docs with color RGB 0,112,112 in Notepad-plus-plus, using “Python Script” plugin. By so, you correct the coloring limitation of Scintilla Library for those keywords in Perl.

Hope this summary will be satisfying enough for “Meta Chuh al.”.

Have nice week (end of) all of you.

Gilles

[Alan Kilborn]

@Gilles-Maisonneuve said:

pissed at my garbage, this includes you Alan

Oh, not at all…at least after 98 messages a positive outcome!

[Ekopalypse]

@Gilles-Maisonneuve

Thank you for your kind words.
I have enjoyed developing the script with you and the
discussion afterwards was also helpful and intersting
as it pointed out that the script comments aren’t 100% bulletproof.
And please don’t hesitate to post here if you find something that
doesn’t work the way you expected it - just let us know, in the end
we can all benefit from it.

Regarding the off topic comments, these were not meant to be insulting.
Sometimes there is a sound in it that is only understood if you read through
several other answers - they are mostly nice but sometimes they do provoke
but they are still meant to be nice or at least helpful.
The one with the summaries, for example, was from another thread where
I caused a confusion, because of my recklessness, that was only cleared up
a few posts later and then I gave a “manager summary” to among other things,
to make life easier for future readers. Seems to become a running gag now :-)

I agree with you, Python is in the beginning odd, especially
when coming from a different language.
It took some time getting used to it and I had my difficulties too,
but now I find the language super - especially Python3, which is
by the way not supported by the PythonScript plugin, :-(
has syntax constructs and language extensions that I really like.

So, have a nice weekend too.

[guy038]

Hello @gilles-maisonneuve, @eko-palypse, @meta-chuh, @alan-kilborn, @peterjones and All,

Ah ! So I’m going to do the 101th post ;-)) Don’t worry, I won’t be [too] long ! I will :

• Explain why my previous regexes did not work ( almost obvious )

• Give you a new version of all the regexes, used in the EkoPalypse script, which :

  • Matches the case qq|qr|qw|qx|q with the < and > delimiters

  • Matches the case of here-docs, containing an escaped delimiter ( \' or \" ), inside the starting and ending blocks ( legal syntax )

For information, refer to :

https://perldoc.perl.org/perlop.html

And particularly :

https://perldoc.perl.org/perlop.html#Quote-Like-Operators

https://perldoc.perl.org/perlop.html#Quote-and-Quote-like-Operators

---

So, Gilles, in my previous regexes, I used the single quote symbol as it ! At that moment I just tested the regular expressions, without using the Python script :-((

Once I decided to use the Eko’s script, I quickly understood that the single quote symbol is, first, interpreted by the Python engine. So, when I changed any ' single quote with the syntax \x27, in my previous regexes, everything went OK ;-))

---

Then, I decided to test the m Perl instruction, first, with all possible delimiters ( See my .pl test file, below )

For instance :

m bPATTERNb
m ZPATTERNZ
m 0PATTERN0
m _PATTERN_
m(PATTERN)
m<PATTERN>
m [PATTERN]
m {PATTERN}
m!PATTERN!
m"PATTERN"
m/PATTERN/
m $PATTERN$
m %PATTERN%
m &PATTERN&
....
....

On the same way, I tried all syntaxes of the PERL instruction qrDelimiterPATTERNDelimiter So, in regex #1, relative to the q PERL instructions, I enumerated all possible delimiters, different from a word char and from the four sets () [] {} <>, in the character class [!"#$%&\x27*+,./:;=?@``|~\\^-]

Note that in that regex #1, I used the special syntax (?|........|.......|... ....|....), which forces the renumbering of the groups, located inside the group, for each alternative ! ( See an example, at the end of that post )

Then, I tried to enumerate all the variations of the here-docs syntax, including special cases as, for instance

$x=<< "TE\"XT";
Plain text here
TE"XT

And I succeeded to manage this case in my new regexes #3 and #4 ;-))

However, note that the highlighting of any here-document is effective ONLY IF the ending text is visible, in the current editor window !

---

So, here are my new regexes :

# Color every instruction word qq|qr|qw|qx|q with PERL Style 5 ( r = 0 v = 0 b = 255 => Blue )

regexes[(1, 5)] = (r'(?s-i)\bq[qrwx]?(?|\h*([!"#$%&\x27*+,./:;=?@`|~\\^-])|\h+(\w)).*?\1', [0])
regexes[(2, 5)] = (r'(?s-i)\bq[qrwx]?\h*(\(.+?\)|\[.+?\]|\{.+?\}|<.+?>)', [0])

# Color every here-document with the USER color r = 255 g = 0 b = 255 ( => Magenta )

regexes[(3, (255,0,255))] = (r'(?s-i)(<<)([\x27"]?)(?|(\w+)\\([\x27"]\w+)|(\w+)())\2\h*;.*?\3\4', [1])
regexes[(4, (255,0,255))] = (r'(?s-i)(<<)\h+(\x27|")(?|(\w+)\\([\x27"]\w+)|(\w+)())\2\h*;.*?\3\4', [1,3,4])

# If, on addition, you want to highlight the END of here-docs :

#regexes[(3, (255,0,255))] = (r'(?s-i)(<<)([\x27"]?)(?|(\w+)\\([\x27"]\w+)|(\w+)())\2\h*;.*?(\3)(\4)', [1,5,6])
#regexes[(4, (255,0,255))] = (r'(?s-i)(<<)\h+(\x27|")(?|(\w+)\\([\x27"]\w+)|(\w+)())\2\h*;.*?(\3)(\4)', [1,3,4,5,6])

If you want to know how these regexes work, I could give you some hints, next time. Just too lazy to do it, right now ;-))

Note also, that I added, in comments, regexes #3 and #4 if you want, also, highlight the end of here-docs, by placing the back-references \3 and \4, inside parentheses => Two new groups 5 and 6

Remark : Do not delete the empty group () in regexes #3 and #4 : it represents an empty group 4, re-used by the back-reference \4

---

And, of course, here is, below, the Test_Gilles.pl file, used to test these 4 new regexes :

#--------------------------------------------------------------------------------------

# Various examples of INSTRUCTION WORDS q, qq, qr, qw, qx, highlighted with the PYTHON script

q/ok/error    q(ok);
qrw/ok/error    q(ok);
qq/ok/error;   qq{ok};
qr/ok/error;   qr(ok);
qw/ok/error;   qw[ok];
qq/ok/error;   qx(ok);

q        xokxerror      q (ok);
qq     hokherror;     qq {ok};
qr                      rokerror;    qr  (ok);
qw aokaerror;   qw [ok];
qx    zokzerror;   qx (ok);

#--------------------------------------------------------------------------------------

my var1 = q xfoobarx;
my var2 = q getservbyname g;
my var3 = q getservbyname getservbyent;
my var4 = qx{ verify > NUL: };
my var5 = qr/$singer.*grand chanteur/;

#--------------------------------------------------------------------------------------

$bar = q(\n);              # or   $bar = '\n'

$foo = qq(\n);             # or   $bar = "\n" ( Interpolation )

$abc = qx(echo .);         # or   $abc = `echo .`

$perl_info  = qx(ps $$);   # That's Perl's $$
$shell_info = qx'ps $$';   # That's the new shell's $$

use POSIX qw( setlocale localeconv )
@EXPORT = qw( foo bar baz );

qr/PATTERN/msixpodualn     # Interpolation occurs unless delimiter is a SINGLE quote '

#--------------------------------------------------------------------------------------

$r = qr//;
$rex = qr/my.STRING/is;
$re = qr/$pattern/;
qr/$_/i

next if qr#^/usr/spool/uucp# ;

#--------------------------------------------------------------------------------------

 my $sentence_rx = qr&
   (?: (?<=^) | (?<=\s) )  # after start-of-string or # whitespace
   \p{Lu}                  # capital letter
   .*?                     # a bunch of anything
   [.?!]                   # followed by a sentence ender
   (?= $ | \s )            # in front of end-of-string or whitespace
  &sx;

#--------------------------------------------------------------------------------------

The cases where WHITESPACE must be used are when the QUOTING character is a WORD character :

q XfooX                    # Means the string 'foo'
qx XfooX                   # Means the string 'foo', too

qXfooX                     # WRONG !
qxXfooX                    # WRONG !

#--------------------------------------------------------------------------------------

# There can (and in some cases, must) be WHITESPACE between the operator and
# the quoting characters, EXCEPT when # is being used as the quoting character :
#
# q#foo# is parsed as the string foo , while q #foo# is the operator q followed by a
# comment. So, its argument will be taken from the next line.

q#foo#

q #foo#   #  => ONLY q SHOULD be colored ( Exception )

#--------------------------------------------------------------------------------------

# Instruction Word m, already CORRECTLY highlighted, by DEFAULT, by Scintilla :

mBPATTERNB   # KO ( normal )
mZPATTERNZ   # KO ( normal )
mbPATTERNb   # KO ( normal )
mzPATTERNz   # KO ( normal )
m0PATTERN0   # KO ( normal )
m9PATTERN9   # KO ( normal )
m_PATTERN_   # KO ( normal )

m BPATTERNB
m ZPATTERNZ
m zPATTERNz
m 0PATTERN0
m 9PATTERN9
m _PATTERN_

m(PATTERN)
m<PATTERN>
m[PATTERN]
m{PATTERN}

m (PATTERN)
m <PATTERN>
m [PATTERN]
m {PATTERN}

m!PATTERN!
m"PATTERN"
m#PATTERN#
m$PATTERN$
m%PATTERN%
m&PATTERN&
m'PATTERN'
m*PATTERN*
m+PATTERN+
m,PATTERN,
m-PATTERN-
m.PATTERN.
m/PATTERN/
m:PATTERN:
m;PATTERN;
m=PATTERN=
m?PATTERN?
m@PATTERN@
m\PATTERN\
m^PATTERN^
m`PATTERN`
m|PATTERN|
m~PATTERN~

m !PATTERN!
m "PATTERN"
m #PATTERN#
m $PATTERN$
m %PATTERN%
m &PATTERN&
m 'PATTERN'
m *PATTERN*
m +PATTERN+
m ,PATTERN,
m -PATTERN-
m .PATTERN.
m /PATTERN/
m :PATTERN:
m ;PATTERN;
m =PATTERN=
m ?PATTERN?
m @PATTERN@
m \PATTERN\
m ^PATTERN^
m `PATTERN`
m |PATTERN|
m ~PATTERN~

#--------------------------------------------------------------------------------------

# Instruction Word qr, CORRECTLY highlighted, with the PYTHON script :

qrBPATTERNB    # KO ( normal )
qrZPATTERNZ    # KO ( normal )
qrbPATTERNb    # KO ( normal )
qrzPATTERNz    # KO ( normal )
qr0PATTERN0    # KO ( normal )
qr9PATTERN9    # KO ( normal )
qr_PATTERN_    # KO ( normal )

qr BPATTERNB
qr ZPATTERNZ
qr bPATTERNb
qr zPATTERNz
qr 0PATTERN0
qr 9PATTERN9
qr _PATTERN_

qr(PATTERN)
qr<PATTERN>
qr[PATTERN]
qr{PATTERN}

qr (PATTERN)
qr <PATTERN>
qr [PATTERN]
qr {PATTERN}

qr!PATTERN!
qr"PATTERN"
qr#PATTERN#
qr$PATTERN$
qr%PATTERN%
qr&PATTERN&
qr'PATTERN'
qr*PATTERN*
qr+PATTERN+
qr,PATTERN,
qr-PATTERN-
qr.PATTERN.
qr/PATTERN/
qr:PATTERN:
qr;PATTERN;
qr=PATTERN=
qr?PATTERN?
qr@PATTERN@
qr\PATTERN\
qr^PATTERN^
qr`PATTERN`
qr|PATTERN|
qr~PATTERN~

qr !PATTERN!
qr "PATTERN"
qr #PATTERN#
qr $PATTERN$
qr %PATTERN%
qr &PATTERN&
qr 'PATTERN'
qr *PATTERN*
qr +PATTERN+
qr ,PATTERN,
qr -PATTERN-
qr .PATTERN.
qr /PATTERN/
qr :PATTERN:
qr ;PATTERN;
qr =PATTERN=
qr ?PATTERN?
qr @PATTERN@
qr \PATTERN\
qr ^PATTERN^
qr `PATTERN`
qr |PATTERN|
qr ~PATTERN~

#--------------------------------------------------------------------------------------

# For completeness, << as shift operator

$b = (1 << 5);

#  Here-documents, CORRECTLY highlighted, with the PYTHON script :

$x=<<TEXT;
Plain text here
TEXT

$x=<<'TEXT';
Plain text here
TEXT

$x=<<"TEXT";
Plain text here
TEXT

$x=<<'TE"XT';
Plain text here
TE"XT

$x=<<"TE'XT";
Plain text here
TE'XT

# Here-documents, with a SPACE char, before the SEMI-COLON

$x=<<TEXT ;
Plain text here
TEXT

$x=<<'TEXT' ;
Plain text here
TEXT

$x=<<"TEXT" ;
Plain text here
TEXT

$x=<<'TE"XT' ;
Plain text here
TE"XT

$x=<<"TE'XT" ;
Plain text here
TE'XT


#  Here-documents, with the ESCAPED delimiter in the TEXT, CORRECTLY highlighted, too !

$x=<<'TE\'XT';
Plain text here
TE'XT

$x=<<"TE\"XT";
Plain text here
TE"XT

# The SAME + a SPACE char, before the SEMI-COLON

$x=<<'TE\'XT' ;
Plain text here
TE'XT

$x=<<"TE\"XT" ;
Plain text here
TE"XT

# Here-documents with SPACE highlights as operator, in Notepad++

$x=<< 'TEXT';
Plain text here
TEXT

$x=<< "TEXT";
Plain text here
TEXT

$x=<< 'TE"XT';
Plain text here
TE"XT

$x=<< "TE'XT";
Plain text here
TE'XT

# The SAME + a SPACE char, before the SEMI-COLON

$x=<< 'TEXT' ;
Plain text here
TEXT

$x=<< "TEXT" ;
Plain text here
TEXT

$x=<< 'TE"XT' ;
Plain text here
TE"XT

$x=<< "TE'XT" ;
Plain text here
TE'XT

#  Here-docs with SPACE highlights as operator, and the ESCAPED delimiter in TEXT, CORRECTLY highlighted !

$x=<< 'TE\'XT';
Plain text here
TE'XT

$x=<< "TE\"XT";
Plain text here
TE"XT

# The SAME + a SPACE char, before the SEMI-COLON

$x=<< 'TE\'XT' ;
Plain text here
TE'XT

$x=<< "TE\"XT" ;
Plain text here
TE"XT


#-----  Note that MULTIPLE Here-docs are NOT managed, yet -:(( -----

print <<"foo", <<"bar"; # you can stack them
I said foo.
foo
I said bar.
bar

myfunc(<< "THIS", 23, <<'THAT');
Here's a line
or two.
THIS
and here's another.
THAT

#------------------ END ----------------------------

Cheers,

guy038

P.S :

Here a simple example of the (?|......|.......|.......)

Let’s suppose that you want to match these two expressions :

foo12345fooABCDE
bar12345barABCDE

A classic syntax should be (foo)12345\1ABCDE|(bar)12345\2ABCDE, where group 1 = foo and group 2 = bar

But you can use this second shorter regex (?|(foo)|(bar))12345\1ABCDE, where group 1 represents, either, foo or bar, depending of the part of the alternative has matched

For a more complete example, refer to :

https://www.boost.org/doc/libs/1_55_0/libs/regex/doc/html/boost_regex/syntax/perl_syntax.html#boost_regex.syntax.perl_syntax.branch_reset

This (?|PATTERN) syntax is, commonly, called a branch-reset !