http://qs321.pair.com?node_id=11121321

Simple maths problem.

an is defined as 1 + (1/n).

Sn is defined as a1 + a2 + ... + an.

So we're gonna calculate S15, and we're gonna use object-oriented programming because I'm me.

use v5.16; package Local::App { use Zydeco; use List::Util 'sum'; class Calc { method a ( PositiveInt $n ) = 1 + (1/$n); method S ( PositiveInt $n ) = sum( map $self->a($_), 1 .. $n ) +; } } my $calc = Local::App->new_calc; say $calc->S(15);

Or, using rational numbers:

use v5.16; package Local::App { use Zydeco; use List::Util 'sum'; class Calc { method r ( $n ) = 1/$n; method a ( PositiveInt $n ) = 1 + $self->r($n); method S ( PositiveInt $n ) = sum( map $self->a($_), 1 .. $n ) +; class +Rational { use Math::BigRat; method r ( $n ) = Math::BigRat->new("1/$n"); } } } my $calc = Local::App->new_calc_rational; say $calc->S(15);

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Re: Solving a maths problem with Perl
by tobyink (Canon) on Sep 03, 2020 at 11:30 UTC

    And yes, I'm aware it can be solved without object-oriented programming.

    use v5.16; package Local::App2 { use List::Util 'sum'; use Exporter::Shiny 'S'; sub a { my $n = shift; 1 + (1/$n); } sub S { my $n = shift; sum( map a($_), 1 .. $n ); } } use Local::App2 'S'; say S(15);

    I like using OOP though because of the ease with which parts can be overridden, like in the rational number version.

Re: Solving a maths problem with Perl
by perlfan (Vicar) on Sep 30, 2020 at 19:08 UTC
    >because I'm me.

    I must say that I, for one, find all the oop modules you're churning out very interesting and fun to watch.