Step through string, x characters at a time, sliding rule

slide_through_string.pl6

#!/usr/bin/env perl6

use v6;

my $input = 'While there was a brief hiatus in the development of the open firmware for Raspberry Pi, we can now boot Linux straight from bootcode.bin (note, this does require an initrd built in with zImage as there are still issues with eMMC working reliably at boot).';
my @input_arr = $input.comb;

my $i = 0;
my %working_set;

# example 1: rotor
my $now = now;
@input_arr.rotor(5 => -4).map: -> @set {
  %working_set{'a', 'b', 'c', 'd', 'e'} = @set;
  say %working_set.perl;
}
say "Example 1 runtime: {now - $now}";

# example 2: while
$now = now;
while $i < @input_arr.elems {
  %working_set{'a', 'b', 'c', 'd'} = @input_arr[$i..$i+3];
  say %working_set.perl;
  $i++;
}
say "Example 2 runtime: {now - $now}";

# Example 1 runtime: 0.0605445
# Example 2 runtime: 0.0288781

# %working_set example output
{:a("W"), :b("h"), :c("i"), :d("l"), :e("e")}
{:a("h"), :b("i"), :c("l"), :d("e"), :e(" ")}
{:a("i"), :b("l"), :c("e"), :d(" "), :e("t")}
{:a("l"), :b("e"), :c(" "), :d("t"), :e("h")}
{:a("e"), :b(" "), :c("t"), :d("h"), :e("e")}
{:a(" "), :b("t"), :c("h"), :d("e"), :e("r")}
{:a("t"), :b("h"), :c("e"), :d("r"), :e("e")}
{:a("h"), :b("e"), :c("r"), :d("e"), :e(" ")}
{:a("e"), :b("r"), :c("e"), :d(" "), :e("w")}
{:a("r"), :b("e"), :c(" "), :d("w"), :e("a")}
{:a("e"), :b(" "), :c("w"), :d("a"), :e("s")}
{:a(" "), :b("w"), :c("a"), :d("s"), :e(" ")}
{:a("w"), :b("a"), :c("s"), :d(" "), :e("a")}
{:a("a"), :b("s"), :c(" "), :d("a"), :e(" ")}
{:a("s"), :b(" "), :c("a"), :d(" "), :e("b")}
...
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