add DDG::Goodie::DuckDuckGo, make HTMLEntities respond properly to control characters

lib/DDG/Goodie/DuckDuckGo.pm

@@ -0,0 +1,33 @@
+package DDG::Goodie::DuckDuckGo;
+# ABSTRACT: Return hard-coded descriptions for DuckDuckGo terms
+
+use DDG::Goodie;
+
+my %data = (
+    zeroclickinfo       => "Zero Click Info is the term DuckDuckGo uses for these boxes, which often provide useful instant answers above traditional results.",
+    zeroclick           => \"zeroclickinfo",
+    help                => "DuckDuckGo's help website: http://help.duckduckgo.com/",
+    help_html           => "DuckDuckGo's help website: <a href='http://help.duckduckgo.com/'>http://help.duckduckgo.com/</a>",
+);
+
+triggers start => keys %data, qw/zero/;
+
+zci is_cached => 1;
+
+handle query_nowhitespace_nodash => sub {
+    $_ = lc;
+    s/\W//g;
+    return unless exists $data{$_};
+    my $answer = $data{$_};
+    my $answerhtml = exists $data{"${_}_html"} ? $data{"${_}_html"} : 0;
+
+    if (ref $answer eq 'SCALAR') {
+        $answer = $data{$$answer};
+        $answerhtml = exists $data{"${answer}_html"} ? $data{"${answer}_html"} : 0;
+    }
+
+    return $answer unless $answerhtml;
+    return $answer, html => $answerhtml;
+};
+
+1;

lib/DDG/Goodie/HTMLEntities.pm

@@ -3,21 +3,31 @@ package DDG::Goodie::HTMLEntities;
 
 use DDG::Goodie;
 use HTML::Entities;
+use Unicode::UCD 'charinfo';
 
 zci answer_type => 'html_entity';
 
 zci is_cached => 1;
 
-triggers query_nowhitespace => qr/^(?:html|entity|htmlentity)?&#?\w+;?$/i;
+triggers query_nowhitespace => qr/^(?:html|entity|htmlentity)?(&#?\w+;?)$/i;
 
-handle query_nowhitespace => sub {
-    s/^(?:html)?(?:entity)?//i;
-    s/;?$/;/; # append a semicolon (some entities like &mdash do not work without one)
-    my $decoded = decode_entities($_);
+handle matches => sub {
+    my $entity = $_[0];
+    $entity =~ s/;?$/;/; # append a semicolon (some entities like &mdash do not work without one)
+    my $decoded = decode_entities($entity);
+    my $decoded_html = $decoded;
     my $decimal = ord($decoded);
+
+    my $info = charinfo($decimal);
+    if( $$info{name} eq '<control>' ) {
+        $decoded_html = "<a href='https://en.wikipedia.org/wiki/Unicode_control_characters'>Unicode control character</a> (no visual representation)";
+        $decoded = "Unicode control character (no visual representation)";
+    }
+    
+
     my $hex = sprintf("%04x", $decimal);
     return "Decoded HTML Entity: $decoded, decimal: $decimal, hexadecimal: $hex", 
-           html => "Decoded HTML Entity: $decoded, decimal: $decimal, hexadecimal: <a href=\"/?q=U%2B$hex\">$hex</a>" unless $_ eq $decoded; # decode_entities will return the input if it cannot be decoded
+           html => "Decoded HTML Entity: $decoded_html, decimal: $decimal, hexadecimal: <a href=\"/?q=U%2B$hex\">$hex</a>" unless $entity eq $decoded; # decode_entities will return the input if it cannot be decoded
     return;
 };
 

t/10-combined.t

@@ -19,6 +19,7 @@ ddg_goodie_test(
 	DDG::Goodie::CurrencyIn
 	DDG::Goodie::DaysBetween
 	DDG::Goodie::Dice
+    DDG::Goodie::DuckDuckGo
 	DDG::Goodie::EmToPx
 	DDG::Goodie::FlipText
 	DDG::Goodie::GUID
@@ -80,6 +81,9 @@ ddg_goodie_test(
     # Dice
     'throw dice'                      => test_zci(qr/\d \d/, answer_type => 'dice_roll', is_cached => 0),
 
+    # DuckDuckGo
+    'zero click info'                 => test_zci("Zero Click Info is the term DuckDuckGo uses for these boxes, which often provide useful instant answers above traditional results.", is_cached => 1, answer_type => 'duckduckgo'),
+
     # EmToPx
     '10 px to em'                     => test_zci('0.625 em in 10 px', answer_type => 'conversion', is_cached => 1),
 

t/DuckDuckGo.t

@@ -0,0 +1,22 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use Test::More;
+use DDG::Test::Goodie;
+
+zci answer_type => 'duckduckgo';
+zci is_cached => 1;
+
+ddg_goodie_test(
+	[qw(
+		DDG::Goodie::DuckDuckGo
+	)],
+	'Zero-Click Info' => test_zci("Zero Click Info is the term DuckDuckGo uses for these boxes, which often provide useful instant answers above traditional results."),
+	'zeroclick' => test_zci("Zero Click Info is the term DuckDuckGo uses for these boxes, which often provide useful instant answers above traditional results."),
+	'help' => test_zci("DuckDuckGo's help website: http://help.duckduckgo.com/", html => "DuckDuckGo's help website: <a href='http://help.duckduckgo.com/'>http://help.duckduckgo.com/</a>"),
+);
+
+done_testing;
+
+