84 lines
2.2 KiB
Plaintext
84 lines
2.2 KiB
Plaintext
Iterator version 0.03
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=====================
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This module is meant to be the definitive implementation of iterators,
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as popularized by Mark Jason Dominus's lectures and recent book
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(_Higher Order Perl_, Morgan Kauffman, 2005).
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An "iterator" is an object, represented as a code block that generates
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the "next value" of a sequence, and generally implemented as a
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closure. Iterator.pm provides a class that simplifies creation and
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use of these iterator objects.
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EXAMPLES
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Synopsis:
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$it = Iterator->new( sub { some code } );
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Simple "upto" counter (Dominus, p. 121):
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sub upto
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{
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my ($m, $n) = @_;
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return Iterator->new( sub {
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return $m++ if $m <= $n;
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Iterator::X::Am_Now_Exhausted->throw();
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});
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}
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my $it = upto (3, 5);
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$i = $it->value; # returns 3
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$i = $it->value; # returns 4
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$i = $it->value; # returns 5
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$i = $it->value; # throws an Iterator::X::Exhausted exception.
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$another_it = upto (7, 10);
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while ($another_it->isnt_exhausted)
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{
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print $another_it->value, "\n";
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}
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# The above prints 7, 8, 9, 10 and throws no exceptions.
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# Another call to $another_it->value would throw an exception.
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DEVELOPMENT STATE
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This is a brand-new module. It has a decent test suite, but has
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not been extensively field-tested. Therefore, it should be considered
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"beta" software, and used with care.
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If you find any bugs, or if any behavior of Iterator surprises you,
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I would be grateful if you could send me an email message about it.
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Thanks.
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INSTALLATION
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To install this module, do the standard Perl module four-step:
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perl Makefile.PL or perl Makefile.pl LIB='my/install/path'
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make
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make test
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make install
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DEPENDENCIES
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This module requires these other modules and libraries:
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Exception::Class
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Test::Simple
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COPYRIGHT AND LICENSE
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Eric J. Roode, roode@cpan.org
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To avoid my spam filter, please include "Perl", "module", or this
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module's name in the message's subject line, and/or GPG-sign your
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message.
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Copyright (c) 2005 by Eric J. Roode. All Rights Reserved.
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This module is free software; you can redistribute it and/or modify it
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under the same terms as Perl itself.
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