comment on

That's a great effort, especially without a compiler. Here are a few corrections and some more "idiomatic" solutions.

Comments in bold italics explain corrections on the previous line.
Comments in normal italics explain stylistic choices on the previous line.

my $life = new life: 20;
[download]

# Indirect object syntax requires colon after invocant


loop { $life.display() }
[download]

# Argumentless &loop is cleaner that &while for infinite loops


class life
{
  has Int          $.count;
  has Int          $.max;
  has Array of Bit @.grid;
[download]

# Bit is potentially much smaller than Int for 1/0 values


  method BUILD(Int $dim)
[download]

# BUILD is the object initializer. # CREATE is something else entirely (see Apocalypse 12 ;-)

  {
    $.count = 0;
    $.max = $dimension-1;
    my Array of Bit @grid is dim($dim,$dim) is default(0);
[download]

# Setting default value to 0 reduces initialization costs

    @grid[$dim / 2 - 1][$dim / 2    ] = 1;
    @grid[$dim / 2 - 1][$dim / 2 + 1] = 1;
    @grid[$dim / 2    ][$dim / 2    ] = 1;
    @grid[$dim / 2    ][$dim / 2 - 1] = 1;
    @grid[$dim / 2 + 1][$dim / 2    ] = 1;
    @.grid := @grid;
[download]

# Can't declare variably dimensioned array as attribute. # Have to declare it when dimension known (i.e. in # constructor) and then bind it to attribute

  }

  sub iterate (&block)
[download]

# Utility sub to factor out repetitive 2D iterations

  {
    for 0..$.max -> $x
[download]

# Prefer &for over &loop when possible (e.g. here)

   {
      for 0..$.max -> $y 
      {
        block($x,$y);
      }
    }
  }

  method calculate() is private 
  {
    my @newgrid;
    iterate
    { 
      my $live = sum(@.grid[$^x-1..$^x+1][$^y-1..$^y+1]);
      @newgrid[$^x][$^y] =  $live==2 && @.grid[$^x][$^y] 
                         || $live==3;
    }
[download]

# Pass &iterate a block with placeholders for $x and $y

    @.grid = @newgrid;
  }

  method display
  {
    iterate { 
      print $.grid[$^x][$^y] ?? '+' :: '.';
      print "\n" if $^x == $.max;
    }
    print "\n";
    print "Turn $(++$.count), press enter to continue or ctl-c to quit
+;
    <$*IN>;
[download]

# STDIN is now $*IN

    .calculate();
  }
}
[download]

Update: Fixed display method (thanks jkahn)

In reply to Re: Prolegemona To A Future Scripting Language: Game Of Life In Perl 6 by TheDamian
in thread Prolegemona To A Future Scripting Language: Game Of Life In Perl 6 by jaldhar

Are you posting in the right place? Check out Where do I post X? to know for sure.
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
Want more info? How to link or How to display code and escape characters are good places to start.


good chemistry is complicated, and a little bit messy -LW
	PerlMonks