#!/usr/bin/env perl
# Copyright (c) 2015 Christian Jaeger, copying@christianjaeger.ch
# This is free software. See the file COPYING.md that came bundled
# with this file.
use strict;
use warnings;
use warnings FATAL => 'uninitialized';
# find modules from functional-perl working directory (not installed)
use Cwd 'abs_path';
our ($mydir, $myname);
BEGIN {
    my $location = (-l $0) ? abs_path($0) : $0;
    $location =~ /(.*?)([^\/]+?)_?\z/s or die "?";
    ($mydir, $myname) = ($1, $2);
}
use lib "$mydir/../lib";
sub usage {
    print "usage: $myname csvfile xmlfile
  Variant of csv_to_xml with shorter code. Only supports one csvfile.
";
    exit(@_ ? 1 : 0);
}
use Getopt::Long;
our $verbose = 0;
GetOptions("verbose" => \$verbose, "help" => sub {usage},) or exit 1;
usage unless @ARGV == 2;
our ($inpath, $outpath) = @ARGV;
use FP::Text::CSV qw(csv_file_to_rows);
use PXML::Serialize;
# create tag functions for the following XML tag names. Casing is
# preserved for the output, but the tag functions are all-uppercase
# (to try to avoid name conflicts and for better visibility) and
# replace the minus with the underscore.
use PXML::Tags qw(myexample protocol-version records record a b c d);
# create a data structure describing an XML document, partially lazily
MYEXAMPLE(
    PROTOCOL_VERSION("0.123"),
    RECORDS(    # read lazy list of rows from CSV file
        csv_file_to_rows($inpath, { eol => "\n", sep_char => ";" })
            # skip the header row
            ->rest
            # map rows to XML elements
            ->map(
            sub {
                my ($a, $b, $c, $d) = @{ $_[0] };
                RECORD A($a), B($b), C($c), D($d)
            }
            )
    )
    )
    # print data structure to disk, forcing its evaluation as needed
    ->xmlfile($outpath);
# XXX this may not actually use constant memory on your Perl. Work
# still needs to be done.