postfix dereference 徹底攻略 / effective postfix dereference

Transcript

1. postfix dereference పఈ߈ུ @mackee_w a.k.a macopy Gotanda.pm #16

2. ୭ˠ • twitter: @mackee_w • GitHub: mackee • kuiperbelt/kuiperbelt :

   WebSocketศར܅ • ࠷ۙPerl Hackers Hubʹςετͱ͔ͷهࣄΛॻ ͍ͨ

3. postfix dereference ͬͯԿ

4. postfix dereference $hashref->%* $arrayref->@*

5. postfix dereference $hashref->%* $arrayref->@*

6. postfix dereference $hashref->%* $arrayref->@*

7. ղઆ

8. postfix dereference %{$hashref} || $hashref->%*

9. postfix dereference @{$arrayref} || $arrayref->@*

10. postfix ɹ= έπʹͭ͘ dereference ɹ= σϦϑΝϨϯε ུ: postderef

11. ֗ͷ੠   ಡΊͳ͍ ͜Ε͸ศརʂ

12. ϝϦο τ

13. ϝϦοτ • ߦͬͯʙฦͬͯͬͯͳΒͳ͍ %{$aaa->{bbb}} $aaa->{bbb}->%* 1 2 3 4 5

    6 7 1 2 3 4 5 6

14. σϝϦοτ

15. ……ͳΜͰ ه߸૿΍ͪ͠Όͬͨͷʁ

16. ͓٬༷ɺ ه߸͸૿΍͓ͯ͠Γ·ͤΜɺ ه߸ͷ૊Έ߹ΘͤΛ૿΍ͨ͠ ͚ͩͳͷͰ͢……

17. ૊Έ߹Θͤ……

18. ୭͕ * ͚ͩͩͱݴͬͨ

19. hash slicing my $hashref = { k1 => "v1", k2

    => "v2", k3 => "v3" }; # ී௨ͷσϦϑΝϨϯε͔ΒͷϋογϡεϥΠε my ($v1, $v3) = @{$hashref}{qw/k1 k3/}; # postderefͰϋογϡεϥΠε my ($v1, $v3) = $hashref->@{qw/k1 k3/};

20. ࣮࣭JSͷobject destructuringͰ͸ʁʁʁ ※ӈลʹ΋ॻ͔ͳ͍ͱ͍͚ͳ͍ͷͰҧ͍·͢ https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment

21. ·ͱΊ • ʢ໨ͱख͕֮͑Ε͹ʣศར • *͚ͩͰ͸ͳ͍ɻΉ͠ΖͦΕҎ֎͕ศར • v5.24͔Βexperimental֎Εͨɻ࢖͑· ͢ʂʂʂʂ • ࠓճͷίʔυ͸શ෦use

    v5.24.0;ͯ͠·͢

22. http://perldoc.jp/docs/perl/5.24.0/perl5240delta.pod

23. postderef_qqͬͯͳʹ

24. postderef_qq my $hashref = { k1 => “v1", k2 =>

    "v2", k3 => "v3" }; print "[$hashref->@{qw/k1 k3/}]\n"; # => [v1 v3]

25. ͳΔ΄Ͳͳʁ

26. csvΈ͍ͨʹग़ͨ͠Γ my @columns = qw/c1 c2 c3/; my $data =

    [ { c1 => "aa", c2 => "bb", c3 => "cc" }, { c1 => "dd", c2 => "ee", c3 => "ff" }, { c1 => "gg", c2 => "hh", c3 => "ii" }, ]; $" = ","; print "@columns\n"; print "$_->@{@columns}\n" for @$data;

27. csvΈ͍ͨʹग़ͨ͠Γ $ perl postderef.pl c1,c2,c3 aa,bb,cc dd,ee,ff gg,hh,ii

28. Ͳ͏Αʁʁʁʁ

29. ײ૝ • ϫϯϥΠφʔͱ͔Ͱศརͦ͏ • jqͷ୅ΘΓʹ࢖͏ͱ͔ • ͱ͸͍͑·ͣv5.24ʹ্͛Δͱ͜Ζ͔Β……