First class environments

func calculator({.is_one}   ) { 1 }
func calculator(n {.is_even}) { n / 2 }
func calculator(n           ) { 3*n + 1 }
 
func succ(this {_{:value}.is_one}, _) {
    return this
}
 
func succ(this, get_next) {
    this{:value} = get_next(this{:value})
    this{:count}++
    return this
}
 
var enviornments = (1..12 -> map {|i| Hash(value => i, count => 0) })
 
while (!enviornments.map{ _{:value} }.all { .is_one }) {
    say enviornments.map {|h| "%4s" % h{:value} }.join
    { |i|
        enviornments[i] = succ(enviornments[i], calculator)
    } << ^enviornments
}
 
say 'Counts'
say enviornments.map{ |h| "%4s" % h{:count} }.join

Output:

   1   2   3   4   5   6   7   8   9  10  11  12
   1   1  10   2  16   3  22   4  28   5  34   6
   1   1   5   1   8  10  11   2  14  16  17   3
   1   1  16   1   4   5  34   1   7   8  52  10
   1   1   8   1   2  16  17   1  22   4  26   5
   1   1   4   1   1   8  52   1  11   2  13  16
   1   1   2   1   1   4  26   1  34   1  40   8
   1   1   1   1   1   2  13   1  17   1  20   4
   1   1   1   1   1   1  40   1  52   1  10   2
   1   1   1   1   1   1  20   1  26   1   5   1
   1   1   1   1   1   1  10   1  13   1  16   1
   1   1   1   1   1   1   5   1  40   1   8   1
   1   1   1   1   1   1  16   1  20   1   4   1
   1   1   1   1   1   1   8   1  10   1   2   1
   1   1   1   1   1   1   4   1   5   1   1   1
   1   1   1   1   1   1   2   1  16   1   1   1
   1   1   1   1   1   1   1   1   8   1   1   1
   1   1   1   1   1   1   1   1   4   1   1   1
   1   1   1   1   1   1   1   1   2   1   1   1
Counts
   0   1   7   2   5   8  16   3  19   6  14   9