File Coverage

blib/lib/Math/NumSeq.pm

Criterion	Covered	Total	%
statement	76	86	88.3
branch	15	20	75.0
condition	11	22	50.0
subroutine	27	29	93.1
pod	9	16	56.2
total	138	173	79.7

# Copyright 2010, 2011, 2012, 2013, 2014 Kevin Ryde

# This file is part of Math-NumSeq.
#
# Math-NumSeq is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 3, or (at your option) any later
# version.
#
# Math-NumSeq is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
# or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
# for more details.
#
# You should have received a copy of the GNU General Public License along
# with Math-NumSeq.  If not, see .


# ($value1,$value2) = $self->ith_pair($i);
# Return values for $i and $i+1, possibly undefs.
# Same as ($self->ith($i), $self->ith($i+1)) but some classes faster.
# SternDiatomic
# Fibonacci -- with ith() being sans last bit
#    ith_pair_from_bits_hightolow()
# LucasNumbers -- F,L then last step L,L
#    ith_FL_from_bits_hightolow()

# $value = $seq->value_floor($value)
# $value = $seq->value_ceil($value)
# $value = $seq->value_next($value)
# characteristic('distinct')
# characteristic('geometric')   geometric progression constant multipler
# characteristic('arithmetic')  arithmetic progression constant add
# characteristic('primitive')   no term divisible by any other
# characteristic('mult_prev')   each term multiple of previous

# $seq->i_end last i if finite, and if known ??
# characteristic('i_end')
# characteristic('i_finite') boolean

# ->add ->sub   of sequence or constant
# ->mul
# ->mod($k)    of constant
# overloads
# ->shift
# ->inverse  some with known ways to calculate
# ->is_subset_of

# lo,hi   i or value
# lo_value,hi_value

# Sequence::Array from arrayref
# Derived::Interleave




package Math::NumSeq;
use 5.004;
use strict;

use vars '$VERSION', '@ISA';
$VERSION = 72;

# uncomment this to run the ### lines
#use Smart::Comments;

BEGIN {
  eval "\n#line ".(__LINE__+1)." \"".__FILE__."\"\n" . <<'HERE'
# print "attempt Locale::Messages for __\n";
use Locale::Messages ();
sub __ { Locale::Messages::dgettext('Math-NumSeq',$_[0]) }
1;
HERE
    || eval "\n#line ".(__LINE__+1)." \"".__FILE__."\"\n" . <<'HERE'
# print "fallback definition of __\n";
sub __ { $_[0] };
1;
HERE
  || die $@;
}

# sub name {
#   my ($self) = @_;
#   my $name = ref($self) || $self;
#   $name =~ s/^Math::NumSeq:://;
#   return $name;
# }

use constant description => undef;
sub oeis_anum {
  my ($self) = @_;
  return $self->{'oeis_anum'} || undef;
}

use constant default_i_start => 1;
sub i_start {
  my ($self) = @_;
  return (defined $self->{'i_start'}
          ? $self->{'i_start'}
          : $self->default_i_start);
}
sub values_min {
  my ($self) = @_;
  return $self->{'values_min'};
}
sub values_max {
  my ($self) = @_;
  return $self->{'values_max'};
}

use constant parameter_info_array => [];
sub parameter_info_list {
  return @{$_[0]->parameter_info_array};
}

# not documented yet
my %parameter_info_hash;
sub parameter_info_hash {
  my ($class_or_self) = @_;
  my $class = (ref $class_or_self || $class_or_self);
  return ($parameter_info_hash{$class}
          ||= { map { $_->{'name'} => $_ }
                $class_or_self->parameter_info_list });
}

# not documented yet
sub parameter_default {
  my ($class_or_self, $name) = @_;
  ### Values parameter_default: @_
  ### info: $class_or_self->parameter_info_hash->{$name}
  my $info;
  return (($info = $class_or_self->parameter_info_hash->{$name})
          && $info->{'default'});
}


#    pn1         values +1, -1, 0
#    permutation
#    delta
#    boolean ?
sub characteristic {
  my $self = shift;
  my $type = shift;
  if (ref $self
      && (my $href = $self->{'characteristic'})) {
    if (exists $href->{$type}) {
      return $href->{$type};
    }
  }
  if (my $subr = $self->can("characteristic_${type}")) {
    return $self->$subr (@_);
  }
  return undef;
}

# default i_start if "increasing"
sub characteristic_increasing_from_i {
  my ($self) = @_;
  return ($self->characteristic('increasing')
          ? $self->i_start
          : undef);
}

# default from the stronger condition "increasing"
sub characteristic_non_decreasing {
  my ($self) = @_;
  return $self->characteristic('increasing');
}
sub characteristic_non_decreasing_from_i {
  my ($self) = @_;
  return ($self->characteristic('non_decreasing')
          ? $self->i_start
          : undef);
}

# default "count" is integer
sub characteristic_integer {
  my ($self) = @_;
  return $self->characteristic_count;
}
use constant characteristic_count => undef; # don't know


#------------------------------------------------------------------------------

sub new {
  my ($class, %self) = @_;
  ### Sequence new(): $class
  my $self = bless \%self, $class;

  foreach my $pinfo ($self->parameter_info_list) {
    my $pname = $pinfo->{'name'};
    if (! defined $self->{$pname}) {
      ### default: $pname
      $self->{$pname} = $pinfo->{'default'};
    }
  }
  $self->rewind;
  return $self;
}

sub tell_i {
  my ($self) = @_;
  return $self->{'i'};
}

sub ith_pair {
  my ($self, $i) = @_;
  return ($self->ith($i), $self->ith($i+1));
}

sub can {
  my ($class, $method) = @_;
  if ($method eq 'ith_pair' && ! return $class->can('ith')) {
    return undef;
  }
  return $class->SUPER::can($method);
}

#------------------------------------------------------------------------------
# shared internals

# cf Data::Float, but it might not handle BigFloat
sub _is_infinite {
  my ($x) = @_;
  return ($x != $x    # nan
          || ($x != 0 && $x == 2*$x));  # inf
}

# or maybe check for new enough for uv->mpz fix
use constant::defer _bigint => sub {
  # Crib note: don't change the back-end if already loaded
  unless (Math::BigInt->can('new')) {
    require Math::BigInt;
    eval { Math::BigInt->import (try => 'GMP') };
  }
  return 'Math::BigInt';
};

sub _to_bigint {
  my ($n) = @_;
  # stringize to avoid UV->BigInt bug in Math::BigInt::GMP version 1.37
  return _bigint()->new("$n");
}

1;
__END__