thundergnat

# Implementing a fixed bit, nominally unsigned Integer class
# Major bummer; can not instantiate usefully in a $ sigiled scalar

class Fixed-Int {
    has $!var handles <FETCH Str Numeric> = 0;
    has $!bits;
    has $!mask;

    submethod BUILD (Int :bits(:$bit)) { $!bits = $bit; $!mask = 2**$!bits - 1 }

thundergnat

# Characters are expensive, and the accountants tell me we can’t hand them out
# willy-nilly anymore. Given a string x and a character y, how many times does y
# occur in x?
put "\nMultiplicity";
sub Multiplicity (Str $a, Str $b) { $a.comb.Bag{$b} }

for < fhqwhgads h mississippi s life . >
  -> $a, $b {  put "$a, $b: ", Multiplicity $a, $b }

thundergnat

my $actions = Moedict::Actions.new();
my @objects;
my @data = .lines # or whatever
(^@data).hyper.map: {
    @objects[$_] = Moedict.parse(@data[$_], :actions($actions)) or die "$!";
}

thundergnat

use soft;
my @log;

sub loggit (*@args) {
    my $return = try { callwith(|@args) };

    #say &?ROUTINE.name; # Off by one call frame
    #say (&::CALLER::&?ROUTINE).name; # just plain wrong
    #.say for Backtrace.new.list; # the wrapped sub name doesn't appear in the backtrace

thundergnat

my $id = 1;
my %customer = (
    $id++ => { :name('aa') :age(9)  },
    $id++ => { :name('bb') :age(22) },
    $id++ => { :name('cc') :age(11) },
);

say 'Sorted by age, descending:';
say "ID# {.key}) Name: {.value<name>}, Age: {.value<age>}"
  for %customer.sort( -*.value<age> );

thundergnat

my %core = (
    :A000001("groups")
    :A000002("kolakoski")
    :A000004("zeroes")
    :A000005("divisors")
    :A000007("zeros-powers")
    :A000009("distinct-partitions")
    :A000010("totient")
    :A000012("ones")
    :A000014("series-reduced-trees")

thundergnat

# Generated by running in the perl6-Math-Sequences directory:
# grep '&NOSEQ ...' ./lib/Math/Sequences/Integer.pm6

# If we don't yet have a formula for a given sequence, we use &NOSEQ in a
our @A000001 is export = 0, 1, 1, 1, 2, 1, 2, 1, 5, 2, 2, 1, &NOSEQ ... *;
our @A000014 is export = 0, 1, 1, 0, 1, 1, 2, 2, 4, 5, 10, 14, &NOSEQ ... *;
our @A000019 is export = 1, 1, 2, 2, 5, 4, 7, 7, 11, 9, 8, 6, &NOSEQ ... *;
our @A000029 is export = 1, 2, 3, 4, 6, 8, 13, 18, 30, 46, 78, &NOSEQ ... *;
our @A000031 is export = 1, 2, 3, 4, 6, 8, 14, 20, 36, 60, 108, &NOSEQ ... *;
our @A000041 is export = 1, 1, 2, 3, 5, 7, 11, 15, 22, 30, 42, &NOSEQ ... *;

thundergnat

sub wat ($n) {
    ($n .. 1).map: -> $m { say "uno: $m" }
    ($n .. 1).map: -> $m { say "dos: $m" }
}

for ^2 -> $m { say "|$m|"; wat($m) } # explicit for loop variable
say '';
for ^2       { say "|$_|"; wat($_) } # implicit for loop variable

thundergnat

# Challenge #1

#`[ Slow, naive, brute force perfect number calculation
sub is-perfect (Int $n) {
    ($n == sum grep $n %% *, 1 .. $n div 2) ??
      $n !!
      Empty
}
]

thundergnat

use Rat::Precise; # thundergnat++

constant D = 54; # does double-duty: number-of-decimals (π), terms in Taylor series (𝑒)
constant d = 15; # digits past decimal for output

# exponentiation where base and exponent are both FatRat
multi infix:<**> (FatRat $base, FatRat $exp where * >= 1 --> FatRat) {
    2 R** $base**($exp/2);
}