From 45be15da3b109c2ef900c87c4a6c59f9419339fa Mon Sep 17 00:00:00 2001
From: Marius Gavrilescu <marius@ieval.ro>
Date: Mon, 30 Apr 2018 23:25:14 +0300
Subject: [PATCH] Initial commit

---
 Changes                      |   4 +
 MANIFEST                     |   6 ++
 Makefile.PL                  |  24 ++++++
 README                       |  31 +++++++
 lib/Data/SExpression/Util.pm | 155 +++++++++++++++++++++++++++++++++++
 t/Data-SExpression-Util.t    |  22 +++++
 6 files changed, 242 insertions(+)
 create mode 100644 Changes
 create mode 100644 MANIFEST
 create mode 100644 Makefile.PL
 create mode 100644 README
 create mode 100644 lib/Data/SExpression/Util.pm
 create mode 100644 t/Data-SExpression-Util.t

diff --git a/Changes b/Changes
new file mode 100644
index 0000000..ccbc0d8
--- /dev/null
+++ b/Changes
@@ -0,0 +1,4 @@
+Revision history for Perl extension Data::SExpression::Util.
+
+0.000_001 2018-04-30T21:25+01:00
+ - Initial release, only a few functions available
diff --git a/MANIFEST b/MANIFEST
new file mode 100644
index 0000000..6ef75f4
--- /dev/null
+++ b/MANIFEST
@@ -0,0 +1,6 @@
+Changes
+Makefile.PL
+MANIFEST
+README
+t/Data-SExpression-Util.t
+lib/Data/SExpression/Util.pm
diff --git a/Makefile.PL b/Makefile.PL
new file mode 100644
index 0000000..44244ec
--- /dev/null
+++ b/Makefile.PL
@@ -0,0 +1,24 @@
+use 5.014000;
+use ExtUtils::MakeMaker;
+
+WriteMakefile(
+	NAME              => 'Data::SExpression::Util',
+	VERSION_FROM      => 'lib/Data/SExpression/Util.pm',
+	ABSTRACT_FROM     => 'lib/Data/SExpression/Util.pm',
+	AUTHOR            => 'Marius Gavrilescu <marius@ieval.ro>',
+	MIN_PERL_VERSION  => '5.14.0',
+	LICENSE           => 'perl',
+	SIGN              => 1,
+	PREREQ_PM         => {
+		qw/Data::SExpression 0.41/,
+	},
+	TEST_REQUIRES     => {
+		qw/Data::Dump::Sexp 0/,
+	},
+	META_ADD          => {
+		dynamic_config => 0,
+		resources      => {
+			repository   => 'https://git.ieval.ro/?p=data-sexpression-util.git',
+		},
+	}
+);
diff --git a/README b/README
new file mode 100644
index 0000000..4c79b7f
--- /dev/null
+++ b/README
@@ -0,0 +1,31 @@
+Data-SExpression-Util version 0.000_001
+=======================================
+
+Data::SExpression::Util contains several routines for processing
+linked lists (represented Data::SExpression::Cons objects). These are
+analogous to Lisp functions with the same names.
+
+INSTALLATION
+
+To install this module type the following:
+
+   perl Makefile.PL
+   make
+   make test
+   make install
+
+DEPENDENCIES
+
+This module requires these other modules and libraries:
+
+* Data::SExpression
+
+COPYRIGHT AND LICENCE
+
+Copyright (C) 2018 by Marius Gavrilescu
+
+This library is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself, either Perl version 5.24.1 or,
+at your option, any later version of Perl 5 you may have available.
+
+
diff --git a/lib/Data/SExpression/Util.pm b/lib/Data/SExpression/Util.pm
new file mode 100644
index 0000000..5ba8da3
--- /dev/null
+++ b/lib/Data/SExpression/Util.pm
@@ -0,0 +1,155 @@
+package Data::SExpression::Util;
+
+use 5.014000;
+use strict;
+use warnings;
+use parent qw/Exporter/;
+
+our %EXPORT_TAGS = ( 'all' => [
+	qw/cons
+	   append
+	   mapcar
+	   rev
+	   position
+	  /]);
+
+our @EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } );
+
+our $VERSION = '0.000_001';
+
+use Data::SExpression::Cons;
+
+sub cons {
+	my ($car, $cdr) = @_;
+	Data::SExpression::Cons->new($car, $cdr);
+}
+
+sub append {
+	my ($expr, $rest) = @_;
+	if (defined $expr) {
+		cons $expr->car, append($expr->cdr, $rest)
+	} else {
+		$rest
+	}
+}
+
+sub mapcar (&@);
+
+sub mapcar (&@) {
+	my ($block, $expr) = @_;
+	if (defined $expr) {
+		my $result;
+		do {
+			local $_ = $expr->car;
+			$result = $block->()
+		};
+		cons $result, mapcar { $block->($_) } $expr->cdr
+	} else {
+		undef
+	}
+}
+
+sub revacc {
+	my ($expr, $acc) = @_;
+	if (defined $expr) {
+		revacc ($expr->cdr, cons($expr->car, $acc))
+	} else {
+		$acc
+	}
+}
+
+sub rev {
+	my ($expr) = @_;
+	revacc $expr, undef;
+}
+
+sub positionacc {
+	my ($expr, $list, $acc) = @_;
+	if (!defined $list) {
+		undef
+	} elsif ($list->car eq $expr) {
+		$acc
+	} else {
+		positionacc($expr, $list->cdr, $acc + 1)
+	}
+}
+
+sub position {
+	my ($expr, $list) = @_;
+	positionacc $expr, $list, 0
+}
+
+1;
+__END__
+
+=encoding utf-8
+
+=head1 NAME
+
+Data::SExpression::Util - routines for processing linked lists
+
+=head1 SYNOPSIS
+
+  use Data::SExpression::Util qw/:all/;
+  my $list = cons 1, cons 2, cons 3, undef; # (1 2 3)
+  my $other_list = cons 4, cons 5, undef; # (4 5)
+
+  $list = append $list, $other_list; # $list is now (1 2 3 4 5)
+
+  say position 1, $list; # 0
+  say position 4, $list; # 3
+  say 'undef' unless defined position 0, $list; # undef
+
+  $list = rev $list; # (5 4 3 2 1)
+  $list = mapcar { $_ + 1 } $list; # (6 5 4 3 2)
+
+  say position 2, $list; # 4
+
+=head1 DESCRIPTION
+
+Data::SExpression::Util contains several routines for processing
+linked lists (represented L<Data::SExpression::Cons> objects). These
+are analogous to Lisp functions with the same names.
+
+Right now very few functions are implemented, more will come in the
+next version.
+
+The list of functions is:
+
+=over
+
+=item B<append>(I<$list>, I<$other_list>)
+
+Appends the list I<$other_list> at the end of the list I<$list>.
+
+=item B<mapcar> { I<block> } I<$list>
+
+Analogous to Perl's map function. Runs I<block> with each element of
+the list I<$list> as $_, and then returns a containing all of the
+result.
+
+=item B<rev>(I<$list>)
+
+Reverses a list
+
+=item B<position>(I<$elt>, I<$list>)
+
+Searches for I<$elt> in I<$list> and returns the first matching
+element (comparison is done via eq).
+
+=back
+
+=head1 AUTHOR
+
+Marius Gavrilescu, E<lt>marius@ieval.roE<gt>
+
+=head1 COPYRIGHT AND LICENSE
+
+Copyright (C) 2018 by Marius Gavrilescu
+
+This library is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself, either Perl version 5.24.1 or,
+at your option, any later version of Perl 5 you may have available.
+
+
+=cut
diff --git a/t/Data-SExpression-Util.t b/t/Data-SExpression-Util.t
new file mode 100644
index 0000000..e1a4f5a
--- /dev/null
+++ b/t/Data-SExpression-Util.t
@@ -0,0 +1,22 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+
+use Test::More tests => 6;
+use Data::Dump::Sexp qw/dump_sexp/;
+BEGIN { use_ok('Data::SExpression::Util', ':all') };
+
+my $list = cons 1, cons 2, cons 3, undef; # (1 2 3)
+my $other_list = cons 4, cons 5, undef;	  # (4 5)
+
+$list = append $list, $other_list; # $list is now (1 2 3 4 5)
+
+is position(1, $list), 0;
+is position(4, $list), 3;
+ok !defined(position 0, $list);
+
+$list = rev $list;
+is dump_sexp($list), '(5 4 3 2 1)';
+
+$list = mapcar { $_ + 1 } $list;   # (6 5 4 3 2)
+is dump_sexp($list), '(6 5 4 3 2)';
-- 
2.39.2