First class environments: Difference between revisions

=={{header|Icon}} and {{header|Unicon}}==

The simplest way to create an environment with variables isolated from code in Icon/Unicon is to create instances of records or class objects.

<lang Icon>link printf

procedure main()

every put(environment := [], hailenv(1 to 12,0)) # setup environments

printf("Sequences:\n")

while (e := !environment).sequence > 1 do {

every hailstep(!environment)

printf("\n")

}

printf("\nCounts:\n")

every printf("%4d ",(!environment).count)

printf("\n")

end

record hailenv(sequence,count)

procedure hailstep(env)

printf("%4d ",env.sequence)

if env.sequence ~= 1 then {

env.count +:= 1

if env.sequence % 2 = 0 then env.sequence /:= 2

else env.sequence := 3 * env.sequence + 1

}

end</lang>

{{libheader|Icon Programming Library}}

[http://www.cs.arizona.edu/icon/library/src/procs/printf.icn printf.icn provides formatting]

{{out}}

<pre>Sequences:

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 </pre>

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

</pre>

=={{header|Perl 6}}==

{{Works with|rakudo|2015-12-17}}

Fairly straightforward. Set up an array of hashes containing the current values and iteration counts then pass each hash in turn with a code reference to a routine to calculate the next iteration.

<lang perl6>my $calculator = sub ($n is rw) {

return ($n == 1) ?? 1 !! $n %% 2 ?? $n div 2 !! $n * 3 + 1

};

sub next (%this, &get_next) {

return %this if %this.<value> == 1;

%this.<value>.=&get_next;

%this.<count>++;

return %this;

};

my @hailstones = map { %(value => $_, count => 0) }, 1 .. 12;

while not all( map { $_.<value> }, @hailstones ) == 1 {

say [~] map { $_.<value>.fmt("%4s") }, @hailstones;

@hailstones[$_].=&next($calculator) for ^@hailstones;

}

say 'Counts';

say [~] map { $_.<count>.fmt("%4s") }, @hailstones;</lang>

{{out}}

<pre> 1 2 3 4 5 6 7 8 9 10 11 12