Data commit

Task/Inverted-index/Perl/inverted-index.pl

@@ -0,0 +1,54 @@
+use Set::Object 'set';
+
+# given an array of files, returns the index
+sub createindex
+{
+    my @files = @_;
+
+    my %iindex;
+
+    foreach my $file (@files)
+    {
+    open(F, "<", $file) or die "Can't read file $file: $!";
+    while(<F>) {
+            s/\A\W+//;
+        foreach my $w (map {lc} grep {length() >= 3} split /\W+/)
+        {
+        if ( exists($iindex{$w}) )
+        {
+            $iindex{$w}->insert($file);
+        } else {
+            $iindex{$w} = set($file);
+        }
+        }
+    }
+    close(F);
+    }
+    return %iindex;
+}
+
+# given an index, search for words
+sub search_words_with_index
+{
+    my %idx = %{shift()};
+    my @words = @_;
+    my $res = set();
+
+    foreach my $w (map {lc} @words)
+    {
+    $w =~ s/\W+//g;            # strip non-words chars
+        length $w < 3 and next;
+        exists $idx{$w} or return set();
+        $res = $res->is_null
+          ? set(@{$idx{$w}})
+          : $res * $idx{$w};       # set intersection
+    }
+    return @$res;
+}
+
+# TESTING
+# USAGE: invidx.pl the,list,of,words file1 file2 .. fileN
+my @searchwords = split /,/, shift;
+# first arg is a comma-separated list of words to search for
+print "$_\n"
+    foreach search_words_with_index({createindex(@ARGV)}, @searchwords);