Perl 6是否有命名元组？

Question

我知道Swift命名了元组:

let twostraws = (name: "twostraws", password: "fr0st1es")

所以我可以说:

print(twostraws.name)  # twostraws

但是在Perl 6中我会说:

my $list = (twostraws, fr0st1es);
say $list[0];

这不像Swift那么棒,所以我想知道Perl 6中是否有命名元组？

Answer 1

有各种方法可以获得类似的东西.

• 简单哈希(推荐)

  my \twostraws = %( 'name' => 'twostraws', 'password' => 'fr0st1es' );
  print twostraws<name>; # twostraws{ qw'name' }
  

• 列表中混合了两种方法

  my \twostraws = ( 'twostraws', 'fr0st1es' ) but role {
    method name     () { self[0] }
    method password () { self[1] }
  }
  
  put twostraws.name; # `put` is like `print` except it adds a newline
  

• 匿名课

  my \twostraws = class :: {
    has ($.name, $.password)
  }.new( :name('twostraws'), :password('fr0st1es') )
  
  say twostraws.name; # `say` is like `put` but calls the `.gist` method
  

可能还有很多我还没有想到的.真正的问题是如何在其余代码中使用它.

Answer 2

枚举可以具有非Int的值类型.您将它们声明为Pairs列表.

enum Twostraws (name => "twostraws", password => "fr0st1es");
say name; # OUTPUT«twostraws?»
say password; # OUTPUT«fr0st1es?»
say name ~~ Twostraws, password ~~ Twostraws; # OUTPUT«TrueTrue?»
say name.key, ' ', name.value; # OUTPUT«name twostraws?»

声明的类型enum可以像任何其他类型一样使用.

sub picky(Twostraws $p){ dd $p };
picky(password); # OUTPUT«Twostraws::password?»

编辑:请参阅https://github.com/perl6/roast/blob/master/S12-enums/non-int.t