Module for Continued Fractions for approximations started.

Manticore/Num/ContinuedFraction.pm

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+package Manticore::Num::ContinuedFraction;
+
+# lazy and potential infinite continued fraction
+
+use strict;
+use warnings;
+
+use Math::BigRat;
+
+# Approximation object:
+#   {
+#     a => BigRat, this integer
+#     r => remainder, input number; undef if fraction has ended
+#     c => child, better approximation (or undef)
+#     e => end of list?
+#   }
+sub new {
+  my ($pkg, $x) = @_;
+  die "ContinuedFraction can only be constructed of positive numbers!" if $x<0;
+  my $prop = int $x;
+  if(0 == $prop) {
+    return undef; # TODO
+  }
+  my $rem = $x - $prop;
+  return bless {
+    a => $prop,
+    r => $rem,
+  }
+}
+
+sub child {
+  my $self = shift;
+  if(not $self->{c}) {
+    my ($a, $r) = @{$self}{qw(a r)};
+    my $c = Manticore::Num::ContinuedFraction->new(1/$r);
+    $self->{c} = $c;
+  }
+  return $self->{c}
+}
+
+1;

tests/testCf.pl

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+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+
+use Math::Trig;
+use Data::Dumper;
+
+BEGIN {
+  push @INC, '..'
+}
+
+use Manticore::Num::ContinuedFraction;
+
+my $pi = Manticore::Num::ContinuedFraction->new(pi);
+
+print $pi->child();
+
+print Data::Dumper::Dumper($pi);
+