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slurp

  "szabgab" .oO "Perl 6 is cool";


  szabgab thinks Perl 6 is cool


  2.78  ~~ 10 +- 3 ?? 't' !! 'f'     # f
  7.5   ~~ 10 +- 3 ?? 't' !! 'f'     # t
  13    ~~ 10 +- 3 ?? 't' !! 'f'     # t
  13.1  ~~ 10 +- 3 ?? 't' !! 'f'     # f


    use v6;

    sub f($a, $b) {
        return "$a - $b";
    }

    say f(4, 2);


    say f(4, 2, 5);


    Too many positional parameters passed; got 3 but expected 2
      in 'f' at line 3:script.p6
      in main program body at line 8:script.p6


    say f(4);


    Not enough positional parameters passed; got 1 but expected 2
      in 'f' at line 3:script.p6
      in main program body at line 8:script.p6


    use v6;
    
    sub f {
        return @_.perl
    }
    
    say f(4, 2);     # [4, 2]
    say f(4);        # [4]
    say f(4, 2, 3);  # [4, 2, 3]


    use v6;
    
    sub f($a, $b?) {
        return defined $b ?? "$a - $b" !! "$a - na";
    }
    
    say f(4, 2);    # 4 - 2
    say f(4);       # 4 - na


    use v6;
    
    sub f($a, $b?) {
        $b //= 17;
        return defined $b ?? "$a - $b" !! "$a - na";
    }
    
    say f(4, 2);    # 4 - 2
    say f(4);       # 4 - na


    Cannot modify readonly value
      in '&infix:<=>' at line 1
      in 'f' at line 4:02.p6
      in main program body at line 8:02.p6


    use v6;
    
    sub f($a, $b = 17) {
        return defined $b ?? "$a - $b" !! "$a - na";
    }
    
    say f(4, 2);    # 4 - 2
    say f(4);       # 4 - 17


    use v6;
    
    sub f($a, $b? is copy) {
        $b //= 17;
        return defined $b ?? "$a - $b" !! "$a - na";
    }
    
    say f(4, 2);    # 4 - 2
    say f(4);       # 4 - 17


    use v6;
    
    sub f($a, Int $b) {
        return "$a - $b";
    }
    
    say f(4, 2);
    say f(4, "foo");


    4 - 2
    Nominal type check failed for parameter '$b'; expected Int but got Str instead
      in 'f' at line 4:03.p6
      in main program body at line 9:03.p6


    use v6;
    
    sub f($a, Int $b where { $b < 10 }) {
        return "$a - $b";
    }
    
    say f(4, 2);
    say f(4, 11);

    4 - 2
    Constraint type check failed for parameter '$b'
      in 'f' at line 4:03.p6
      in main program body at line 9:03.p6


    sub infix:<.oO>($name, $thought) {  
        say "$name thinks $thought"
    }


    sub infix:<+->($a, $b) { ($a-$b) .. ($a+$b) }


   5 +- 2


    perl6-users-subscribe@perl.org


  my %h = "Foo" => 1, "Bar" => 2;
  

  say %h.perl;    # {"Foo" => 1, "Bar" => 2}


  say %h{"Foo"};  # 1
  

  say %h{Foo};    # Could not find sub &Foo


  my $name = "Foo";
  say %h{$name};   # 1


  say <Foo Bar>;   # FooBar
  

  say %h<Foo>;     # 1


  say %h<Foo Bar>;  # 1 2


  say %h<Foo Bar>.perl;  # (1, 2)


  for %h.keys -> $k { say "$k %h{$k}"; }


  for %h.values -> $v { say $v; }


  for %h.kv -> $k, $v { say "$k - $v"; }


  %h<Moo> = 3;

  say %h.perl;    # {"Moo" => 3, "Foo" => 1, "Bar" => 2}


  %h<Moo> = 4;
  say %h.perl;   # {"Moo" => 4, "Foo" => 1, "Bar" => 2}


  %h.push( 'Moo' => 5 );
  say %h.perl;   # {"Moo" => [4, 5], "Foo" => 1, "Bar" => 2}


  use v6;

  my $content = slurp "text.txt";
  say $content.chars;


  use v6;

  my @content = slurp "text.txt";
  say @content.elems;
  say @content[0].chars;


  use v6;

  my @content = lines "text.txt";
  say @content.elems;
  say @content[0].chars;


  use v6;

  for lines "text.txt" -> $line {
    say $line.chars;
  }


  use v6;
  my $fh = open "text.txt";

  my $first_line = $fh.get;
  say $first_line;

  for $fh.lines -> $line {
    say $line.chars;
  }


  use v6;

  my $fh = open "out.txt", :w;
  $fh.say("text 4");
  $fh.close;

  say slurp "out.txt";


  use v6;
  my @people = ;
  for @people -> $n {
    say $n;
  }


  use v6;
  my @people = ;
  for 0 .. @people.elems/2 -> $i {
    say "@people[$i*2] -  @people[$i*2+1]";
  }


  use v6;
  my @people = ;
  for @people -> $name, $phone {
    say "$name - $phone";
  }


  use v6;
  my @names = ;
  my @phones = <123 456 789 512>;
  for @names Z @phones -> $name, $phone {
    say "$name - $phone";
  }


  use v6;
  for 1 .. 10 -> $n {
    say $n;
  }


  use v6;
  for 1,3 ... Inf -> $n {
    say $n;
    last if $n > 10;
  }

Blog

Welcome back to the Perl 6 Tricks and Treats

The Thought operator

The +- operator

Subroutines in Perl 6

Perl 5 style in Perl 6

Optional parameter

Parameters are read-only

Default value of a parameter

Making the parameter a copy and thus changeable

Type restrictions on parameters

Other constraints on parameters

Creating operators in Perl 6

Comments and Discussion

Perl 6 Code examples

Perl 6 Code examples

Perl 6 Code examples