メソッドの話

Perl6 になって，メソッドがよくわからんくなった．
あとメタプログラミングRuby を読んで，どこにメソッドが差してあるかが
気になってきた今日このごろ．

少し調べてみることにする．

class C11              { method f {say "C11"} }
class C12              { method f {say "C12"} }
class C21              { method f {say "C21"} }
class C22              { method f {say "C22"} }
class B1 is C11 is C12 { method f {say "B1"} }
class B2 is C21 is C22 { method f {say "B2"} }
class A  is B1  is B2  { method f {say "A"} }

my $obj = D.new;
say $obj.WHAT; # D()
say $obj.^parents(:tree).perl; # ([B1, [C11, [Any, [Mu]]], [C12, [Any, [Mu]]]], [B2, [C21, [Any, [Mu]]], [C22, [Any, [Mu]]]])

A -+- B1 -+- C11
      |      |
      |      C12
      |
      B2 -+- C21
             |
             C22

role C11                  { method f {say "C11"} }
role C12                  { method f {say "C12"} }
role C21                  { method f {say "C21"} }
role C22                  { method f {say "C22"} }
role B1 does C11 does C12 { method f {say "B1"} }
role B2 does C21 does C22 { method f {say "B2"} }
class A does B1  does B2  { method f {say "A"} }

A -+- B1 -+- C11
      |      |
      |      C12
      |
      B2 -+- C21
             |
             C22