$into_qr = qr/\s(?:\-|en|in|to|in ?to)\s/i;

$q_check = $q;
$q_check =~ s/^\!//;
$q_check =~ s/\?$//;

$q_escape = encode_for_link($q);

$q_internal is $q minus special chars

$q =~ /^!?(?:(?:\()*(?=[ABCDEFGHIKLMNOPRSTUVWXYZ])(?:S[gnbmreic]?|N[eoabdip]?|G[dae]|B[ariehk]?|U(?:u[ptsohq])?|P[troamdbu]?|M[dgton]|A[ltrmgcus]|I[nr]?|R[bengaufh]|C[rnldumofsae]?|L[ruia]|E[rus]|T[hlacemib]|D[ys]|H[eogsaf]?|F[emr]?|Kr?|Yb?|Z[rn]|Os?|[VW]|Xe)(?:\d|\))*)+$/ && $q =~ /(\d+)/ && $1<20

$q_check =~ /\bcal[ea]nd[ae]r\b/i && $q_check =~ /\b(?:\d{4}|jan(?:uary|)|feb(?:r?uary|)|mar(?:ch|)|apr(?:il|)|may|june?|july?|aug(?:ust|)|sep(?:tember|)|oct(?:ober|)|nov(?:ember|)|dec(?:ember|))\b/

$q_check =~ /^(?:convert\s|)[^a-z]?\d[\d\,\.]*\s?.{1,10}$into_qr(?:.{1,15}|[^\s]+)$/i

$q_check =~ /^.{1,10}\s*[^a-z]?\d[\d\,\.]*$into_qr(?:.{1,15}|[^\s]+)$/i

$q_escape =~ s/(\b|\%20)cad(\b|\%20)/$1canadian dollars$2/i;
$q_escape =~ s/(\%20)en(\%20)/$1in$2/i;
$q_escape =~ s/(\b|\%20)jst(\b|\%20)/$1jt$2/i;
$q_escape =~ s/(\b|\%20)bht(\b|\%20)/$1thb$2/i;
$q_escape =~ s/(\d)\%2C(\d{2})(?!\d)/$1.$2/i;

my $currency_qr = qr/\b(?=[abcdefghijklmnopqrstuvwxyz])(?:a(?:o[an]|r[asp]|fa|ll|[mue]d|[wn]g|zm)|d(?:zd|kk|jf|op)|u(?:a[hk]|sd|[gz]s|yu|kp)|e(?:ur|gp|ek|tb|cs|rn)|x(?:cd|[apo]f|eu)|n(?:ok|[za]d|pr|ic|gn)|b(?:o[bp]|[shbzmn]d|dt|yr|am|wp|[rg]l|if|tn|uk)|k(?:hr|[yw]d|mf|zt|[eg]s|[pr]w)|c(?:l[fp]|[as]d|ve|ny|[ou]p|rc|zk|hf|dz)|t(?:pe|[wtn]d|jr|zs|hb|op|ry|mm)|f(?:kp|jd)|g(?:[my]d|el|hc|[ibw]p|tq|ns|qe)|h(?:r[kd]|tg|nl|kd|uf)|i(?:sk|[ndr]r|qd|ls)|j(?:[mo]d|py)|l(?:s[lm]|ak|[vt]l|bp|[ry]d|kr)|m(?:x[np]|op|[ka]d|[gl]f|[wm]k|[yvu]r|ro|dl|nt|zm)|p(?:e[ins]|l[nz]|kr|gk|yg|hp|ab)|r(?:u[br]|ol|wf)|s(?:[tgb]d|[acu]r|[lz]l|os|[hy]p|[dr]g|ek)|z(?:ar|mk|rz)|v(?:uv|ef|nd)|y(?:er|dd)|(?:om|qa)r|wst)\b/i;

$q_check =~ /^$currency_qr$into_qr$currency_qr$/i

$q_escape =~ s/(\%20)en(\%20)/$1in$2/i;

my ($ss,$mm,$hh,$day,$month,$year,$zone) = strptime($q);
{
    if ($day && length($day)==4) {
        $year = $day;
        $day = '';
    }
}
if ($month && ($day || $year)) {
  my $tmp_q = $q_escape;
  if ($month && $day) {
  if (!$year) {
    my ($sec,$min,$hour,$mday,$mon,$year2,$wday,$yday,$isdst) =
    localtime(time);
    $year2 = $year2 + 1900;
    $year2 += 1 if $month<$mon || ($month==$mon && $day<$mday);
    $q_escape .= qq(+$year2);
  }
} elsif ($month && $year) {

}

$query =~ /^(?:(?:number|height|volume|area|circumference|capital) of|mass|radius|density|distance|elevation|population|age|(?:birth|death)\s?(?:year|date)|weight|sun(?:rise|set)|calories|tides?)\s+.*$/i

$query =~ /^.*\s+(?:mass|radius|density|distance|elevation|population|age|(?:birth|death)\s?(?:year|date)|weight|sun(?:rise|set)|calories|tides?)$/i

$query =~ /\bhow many\b.*\b(?:in|on)\b/i

my %holidays = map { $_ => undef } (
    'mlk day',
    'mlk',
    'martin luther king day',
    'martin luther king',
    'martin luther kings birthday',
    'presidents day',
    'presidents',
    'washingtons birthday',
    'memorial day',
    'memorial',
    'independence day',
    'independence',
    'labor day',
    'labor',
    'columbus day',
    'columbus',
    'veterans day',
    'veterans',
    'thanksgiving',
    'fathers day',
    'fathers',
    'mothers day',
    'mothers',
    'inauguration day',
    'inauguration',
    'ash wednesday',
    'shrove tuesday',
    'groundhog day',
    'groundhog',
    'saint patricks day',
    'saint patricks',
    'easter',
    'earth day',
    'earth',
    'arbor day',
    'arbor',
    'cinco de mayo',
    'st patricks day',
    'st patricks',
    'flag day',
    'flag',
    'rosh hashanah',
    'yom kippur',
    'passover',
    'halloween',
    'election day',
    'election',
    'hanukkah',
    'christmas',
    'christmas day',
);

exists $holidays{$query}

$q_internal =~ /^!?(?:date\s|day\s|\d{4}\s|\d{2}\s)+(?:of\s|)(.*)\??$/ || $q_internal =~ /^!?(?:(?:when|what) is |(?:how many |)days (?:to |till |until? |for |of )|)(.*?)(?: date| day| \d{4}| \d{2})*\??$/) && exists $holidays{$1}

$tmp_q_escape =~ s/\%27//g;
$tmp_q_escape =~ s/\b(\d{2})\b/my $a = $1;($a<20) ? ($a+=2000) : ($a+=1900)/e;

my %location_results = map { $_ => undef } (
    'time',
    'current time',
    'local time',
    'weather',
    'sunrise',
    'sunset',
    'tide',
    'tides',
    );

exists $location_results{$q_check} && $q_check ne 'weather'

$q_check =~ /^\d+\!$/ 

$q_check =~ /^\(?[\d,]+\s?[a-z]+\s*[\^\-\*\(\)\+\/]\s*\d+/i

($q_check =~ /^[xX\^\-\*\(\)\+\/\s\d\,]+$/ && $q !~ /^[\d,]+$/)

($q =~ /(?:\d|\b(?:pi|[xX]|e|one|two|three|four|five|six|seven|eight|nine|ten)\b)/ && $q =~ /(?:\b(?:pi|sqrt|lim|sin|cos|tan|sec|csc|cot|arcsin|arccis|arctan|arccsc|sinh|mod|cosh|tanh|csch|arsinh|arccsch|ln|log|lg|exp|int|choose|integral|days|integrate|sum|derivative|times|divided by|plus|minus|prime|factori[zs]e|sq(?:uare) root)\b|\% of|=)/i)

exists $stocks{lc $query}

length($q)==1

$q_check =~ /^U\+([\da-f]{4})$/i

$query eq 'time'

$query =~ /^(?:current\s|what\s|)(?:(?:local\s?|)time|clock)\s(.*)$/i

$query =~ /\s(?:current\s|what\s|)(?:(?:local\s?|)time|clock)$/i

$query =~ /^(?:what is|what\'s|)\s*(?:today\'?s|)\s*date\s*(?:today|)$/i

$query =~ /^\d{1,2}\:?\d{0,2}[ap]\.?m\.?(?:\s|\Z)/i

$q_escape =~ s/clock/time/i;
$q_escape .= '+time' if $q_escape !~ /time$/i;

 Copyright (c) 2010 Duck Duck Go, Inc.

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.