Raku oddNumbers Iterator (following Nim example)

iterator.raku

#`[Nim example:

# Thanks to Nim's 'iterator' and 'yield' constructs,
# iterators are as easy to write as ordinary
# functions. They are compiled to inline loops.
iterator oddNumbers[Idx, T](a: array[Idx, T]): T =
  for x in a:
    if x mod 2 == 1:
      yield x

for odd in oddNumbers([3, 6, 9, 12, 15, 18]):
  echo odd
#]

# Raku version:

class oddNumbers is Array {
    method iterator {
        class :: does Iterator {
            has $.array;
                
            method pull-one {
                given $.array {
                    .shift if .first %% 2;  
                    .shift // IterationEnd;
                }   
            }   
        }.new(array => self)
    }   
}
 
for (oddNumbers.new = [3, 6, 9, 12, 15, 18]) -> \odd {
    say odd 
}

# Raku more naturally using gather/take

sub oddNumbers( @a ) { 
    lazy gather {
        for @a {
            take $_ unless $_ %% 2
        }   
    }   
}

.say for oddNumbers([3, 6, 9, 12, 15, 18]);

# Or raku with grep

[3, 6, 9, 12, 15, 18].grep(not * %% 2).say