File Coverage

blib/lib/Math/NumSeq/Base/IteratePred.pm

Criterion	Covered	Total	%
statement	31	31	100.0
branch	4	4	100.0
condition			n/a
subroutine	9	9	100.0
pod	0	2	0.0
total	44	46	95.6

# Copyright 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 .

package Math::NumSeq::Base::IteratePred;
use 5.004;
use strict;
use List::Util 'max';

use vars '$VERSION';
$VERSION = 72;

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

use constant characteristic_increasing => 1;
use constant characteristic_integer => 1;
use constant characteristic_smaller => 0;

sub rewind {
  my ($self) = @_;
  ### IteratePred rewind() ...

  $self->{'i'} = $self->i_start;
  my $value = $self->values_min;
  if (! defined $value) { die "Oops, no values_min() for predicate start"; }
  $self->{'value'} = $value;

  ### i: $self->{'i'}
  ### $value
}

sub next {
  my ($self) = @_;
  ### IteratePred next() at value: $self->{'value'}

  for (my $value = $self->{'value'}; ; $value++) {
    if ($self->pred($value)) {
      $self->{'value'} = $value+1;
      return ($self->{'i'}++, $value);
    }
  }
}

# Would have to scan all values to find correct i.
# sub seek_to_value {
#   my ($self, $value) = @_;
#   $value = int($value);
#   $self->{'value'} = max ($value, $self->values_min);
#   $self->{'i'} = ...
# }

# Slow to scan through all values.
# sub ith {
#   my ($self, $i) = @_;
#   $i -= $self->i_start;
#   my $value = $self->value_min - 1;
#   while ($i >= 0) {
#     $value++;
#     if ($self->pred($value)) {
#       $i--;
#     }
#   }
#   return $value;
# }


1;
__END__