Hi William, I guess that you now have answers to your questions. I would suggest, however, that you take a look as Andrew Shitov's book *Raku One-Liners*, available on-line ( https://andrewshitov.com/wp-content/uploads/2020/01/Raku-One-Liners.pdf).
There are (around page 12) some explanations on your original question. Consider especially the following equivalent one-liner programs: $ raku-npe'.=flip' data.txt and $ raku-ne'.flip.say' data.txt and the related explanations. Cheers, Laurent. Le jeu. 7 mai 2020 à 10:12, Gianni Ceccarelli <dak...@thenautilus.net> a écrit : > On 2020-05-06 William Michels via perl6-users <perl6-us...@perl.org> > wrote: > > Are there any other "operators that modify their operands" in > > Raku/Perl6 that don't require an initializing "." (dot)? > > The dot is used to call a method on an object. > > > I checked the "subst" command and it requires an initial ".=" when > > used with the "-pe" one-liner flag: > > ``subst`` is a method https://docs.raku.org/type/Str#method_subst > > To summarise: > > * ``-e`` tells raku "execute the next argument as a program" > > * both the ``-p`` and ``-n`` command-line switches wrap the program in > a loop like:: > > for $*ARGFILES.lines -> { > > } > > ``-p`` additionally puts a ``say $_`` at the end of the block > > * inside that loop, the variable ``$_`` will have its value set to > each line of the input, one at a time > > * you can do whatever you want inside the loop > > * the dot calls a method, and if you don't specify an object to call > the method on (on the left hand side of the dot), ``$_`` is used > > * some operators (like ``s///`` or ``tr///``) operate on ``$_`` unless > told otherwise > > * assignment (``=``) can be combined with other operators (``+=``, > ``/=``, ``.=``, ``~=``, &c) > > If, having seen all that, the behaviour of all your examples is still > not clear, maybe you should start writing your programs without > shortcuts and implicit terms: the languages in the Perl family are > very good at letting you write compact code, but sometimes this comes > at the expense of clarity. While learning, code that's clear, > explicit, and straightforward is often more helpful. > > -- > Dakkar - <Mobilis in mobile> > GPG public key fingerprint = A071 E618 DD2C 5901 9574 > 6FE2 40EA 9883 7519 3F88 > key id = 0x75193F88 >
