Haskell to Perl 6

Post by dragonwriter » Sun, Dec 09, 2018, 2:21 AM UTC

herrosheep wrote: post #3

I'd like to hear opinions on how the use of sigils and the other syntax oddities like Int:D, Int:U, given, when, etc improves the codabliity/readability of Perl 6 vs other languages. The examples vs Haskell are not helping me understand. Personally I don't think the added verbosity is helping in any way.

Post by raiph » Sun, Dec 09, 2018, 2:38 AM UTC

herrosheep wrote: post #92

lizmat wrote: post #74

Earlier quoted context omitted.

Would you care to elaborate on the non-clean parts in your opinion?

Things like this seem like odd design choices: my @menu = ; say @menu.contains('hamburger'); # True say @menu.contains('hot dog'); # False say @menu.contains('milk'); # True! say @menu.contains('er fr'); # True! say @menu.contains( ); # True!

    my @menu = ;
    say so @menu.grep('hamburger');            # True 
    say so @menu.grep('hot dog');              # False 
    say so @menu.grep('milk');                 # False 
    say so @menu.grep('er fr');                # False 
    say so @menu.grep();                # False

Post by sacomo » Sun, Dec 09, 2018, 8:41 AM UTC

mmirate wrote: post #53

kbenson wrote: post #37

Earlier quoted context omitted.

> Except the resulting code will look nothing like “the humans say it”, Actually, I find it maps rather directly to how a lot of people explain things. For example, "Examine each number, and as long as it's greater than 10 and odd, then pass it to the the work function." for my $number ( @numbers ) { next unless $number > 10; next unless $number % 2; work($number); } Perl generally allows you to structure your code a…

That ought to be a oneliner in any sane language today: numbers.into_iter().filter(|n| n>10 && n%2!=0).for_each(work); map work . filter ((/=0) . (`mod` 2)) . filter (>10) $ numbers Insert tirade about how for-loops are free to do so much that they are slower-to-comprehend than specific-purpose iterator/list functions, here.

  @numbers.grep(* > 10 && * % 2)>>.&work;

Post by xisukar » Sun, Dec 09, 2018, 2:33 PM UTC

herrosheep wrote: post #92

lizmat wrote: post #74

Earlier quoted context omitted.

Would you care to elaborate on the non-clean parts in your opinion?

Things like this seem like odd design choices: my @menu = ; say @menu.contains('hamburger'); # True say @menu.contains('hot dog'); # False say @menu.contains('milk'); # True! say @menu.contains('er fr'); # True! say @menu.contains( ); # True!

    # Let's drop `` (quote-words constructor) and 
    # use a more familiar array of strings:
      
    my @menu = 'hamburger', 'fries', 'milkshake';
      
    # Let's look at the definition of the `Str` method in 
    # the `List` class from which the `Array` class inherits:
    
    #`{
      method Str(List:D: --> Str:D)
      Stringifies the elements of the list and joins
      them with spaces (same as .join(' ')).
    }

    # Thus, after being stringfied, @menu is treated as 
    # the string 'hamburger fries milkshake'
    
    # With this is in hand, we can gauge the possible
    # result of the following statements:
    
    say @menu.contains('hamburger');            # True 
    say @menu.contains('hot dog');              # False 
    say @menu.contains('milk');                 # True
    say @menu.contains('er fr');                # True 
    say @menu.contains();                # True

    say 'hamburger' (