raku

I've been looking at the various ways of constructing lazy lists in Perl 6 and I would like to collect all of the concise ways of describing the Fibonacci sequence. I will start this off with the three from masak 's journal: my @fibs := (0, 1, -> $a, $b { $a + $b } ... *); my @fibs := (0, 1, { $^a + $^b } ... *); my @fibs := (0, 1, *+* ... *); I was thinking something like this would also work, but I think I have the syntax wrong: my @fibs := (0, 1, (@fibs Z+ @fibs[1..*])); Something there is eager (the slice?) and causes Rakudo to enter an infinite loop. It's a translation of the Haskell

Perl 6 seems to have an explosion of equality operators. What is =:= ? What's the difference between leg and cmp ? Or eqv and === ? Does anyone have a good summary? =:= tests if two containers (variables or items of arrays or hashes) are aliased, ie if one changes, does the other change as well? my $x; my @a = 1, 2, 3; # $x =:= @a[0] is false $x := @a[0]; # now $x == 1, and $x =:= @a[0] is true $x = 4; # now @a is 4, 2, 3 As for the others: === tests if two references point to the same object, and eqv tests if two things are structurally equivalent. So [1, 2, 3] === [1, 2, 3] will be false

I'm playing around with lines which reads lines from the files you specify on the command line: for lines() { put $_ } If it can't read one of the filenames it throws X::AdHoc (one day maybe it will have better exception types so we can grab the filename with a .path method). Fine, so catch that: try { CATCH { default { put .^name } } for lines() { put $_ } } So this catches the X::AdHoc error but that's it. The try block is done at that point. It can't .resume and try the next file: try { CATCH { default { put .^name; .resume } } # Nope for lines() { put $_ } } Back in Perl 5 land you get a

Functions can be called in a couple ways: say(1, 2, 3) # 123 say: 1, 2, 3 # (1, 2, 3) The latter seems to pass a Positional , but apart from that I don't know how else they differ. Are there any differences that are important to know? What types of situations would you use one over the other? jjmerelo As Raiph tells you above, say: is a label. So you didn't say anything (even though you thought you did) and -- outside use of the REPL -- the compiler will complain that your use of <a b c> was useless: say: <a b c>; # OUTPUT: «WARNINGS for <tmp>:␤Useless use of constant value a b c in sink

I have this .bib file for reference management while writing my thesis in LaTeX: @article{garg2017patch, title={Patch testing in patients with suspected cosmetic dermatitis: A retrospective study}, author={Garg, Taru and Agarwal, Soumya and Chander, Ram and Singh, Aashim and Yadav, Pravesh}, journal={Journal of Cosmetic Dermatology}, year={2017}, publisher={Wiley Online Library} } @article{hauso2008neuroendocrine, title={Neuroendocrine tumor epidemiology}, author={Hauso, Oyvind and Gustafsson, Bjorn I and Kidd, Mark and Waldum, Helge L and Drozdov, Ignat and Chan, Anthony KC and Modlin, Irvin