[Mastering-perl] Ch. Advanced regular expressions

[Florian Merges]

Hi,


Ch. Advanced regular expressions
=========================

Section: (?imsx-imsx:PATTERN)
-----------------------------------------------

I modify that snippet to use the /i flag to turn on case-insensitivity:

my $regex = qr/(\S+) hacker/;                  # ====> Where is the /i flag?
print "$regex\n";

The output now shows me that case-insensitivity is on, but the other flags
are off.

(?i-xsm:(\S+) hacker)

Section: Lookahead assertions, (?!PATTERN) and (?=PATTERN)
----------------------------------------------------------

I use a string with five 's followed by a b.       ====> I use a string with
five a's followed by a b.

I think this section can be explained in a better way... it's a lil' bit
confusing. same than the next one.

Section: Lookbehind assertions, (? and (?<=PATTERN)               ====> (?<!
PATTERN) and (?<= PATTERN)
---------------------------------------------------

number of os in fooo:                     ====>  o's

Last example, is it correct the operation it does?

Section: Global matching
-------------------------------------

my $line = "Just another regex hacker, Perl hacker, and that's it!\n";

while( 1 )
    {
    my( $found, $type )= do {
        if( $line =~ /\G([a-z]+(?:'[ts])?)/igc )

            { ( $1, "a word"           ) }                 # ====> s/a
word/word/



Regards,

Florian
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