use strict;
use warnings;
open my $words, "<", "words.txt" or die "Cannot open words.txt: $!\n";
my $lasttype;
my @text;
while( <$words> ) {
chomp;
my @row = split /\t/;
my $text = $row[0];
my $type = ( $row[-1] =~ /\w-(\w+)/ ) ? $1 : "";
$lasttype = $type unless @text; # special treatment for first row
if( $type eq $lasttype ) {
push @text, $text;
} else {
print ''."$lasttype@text\n" if $lasttype;
$lasttype = $type;
@text = ( $text );
}
}
# print what's left over when all input read
print ''."$lasttype@text\n" if $lasttype;
close $words;