tame/build-aux/lib/zipre.php

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<?php
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/**
* Generate regular expressions to match a list of zip codes
*
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* Copyright (C) 2014-2021 Ryan Specialty Group, LLC.
2016-08-24 10:19:11 -04:00
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
function gen_re_quick( $data )
{
$re = ( '^' . gen_re( $data, 0 ) );
// attempt to simplify the regex (we're not going to put a lot of effort into
// this)
return re_simplify( $re );
}
function gen_re( $data, $offset )
{
// if we've reached the end of the zip length, or if there's no more zips to
// look at, then stop
if ( ( count( $data ) === 0 )
|| ( $offset === 5 )
)
{
return '';
}
$out = '(';
// loop through each digit at the current offset
$last = '';
foreach ( $data as $zip )
{
if ( !( isset( $zip[ $offset ] ) ) )
{
continue;
}
$digit = $zip[ $offset ];
// if we've already seen this digit in the current position, then
// continue
if ( $digit === $last )
{
continue;
}
// we're going to recurse now, delimiting allowable digits with pipes
// (for 'OR'); we'll recurse on a sublist that matches the zip up to
// (and including) the current digit (to do this, note that we only need
// to check the current digit, since our current list is already a
// sublist of the parent list up to the current point)
$prefix = substr( $zip, 0, $offset + 1 );
$out .= ( $last === '' ) ? '' : '|';
$out .= $digit . gen_re(
filter_data( $data, $digit, $offset ),
( $offset + 1 )
);
$last = $digit;
}
return $out . ')';
}
function filter_data( $data, $chr, $offset )
{
$ret = array();
foreach ( $data as $val )
{
if ( $val[ $offset] === $chr )
{
$ret[] = $val;
}
}
return $ret;
}
function re_simplify( $re )
{
// the only simplification we currently do is joining sequential digit ORs
// into a character range (e.g. (1|2|3|4) becomes [1-4])
return preg_replace_callback( '/\([0-9](\|[0-9])*\)/', function( $results )
{
$match = $results[ 0 ];
$digits = explode( '|', str_replace( array( '(', ')' ), '', $match ) );
// are the digits sequential (we will only perform this optimization if
// there's more than 3 digits, since otherwise the replacement would
// result in a string of equal or greater length)?
if ( ( count( $digits ) > 3 ) && is_seq( $digits ) )
{
return sprintf( '[%d-%d]',
$digits[ 0 ],
$digits[ count( $digits ) - 1 ]
);
}
elseif ( count( $digits ) === 1 )
{
// if there's only one digit, then that's all we need to return
return $digits[ 0 ];
}
return '[' . implode( '', $digits ) . ']';
}, $re );
}
function is_seq( $digits, $last = '' )
{
// stop recursing once we're out of digits
if ( count( $digits ) === 0 )
{
return true;
}
// grab the current digit and remove it from the list (this has the effect
// of both cons and cdr)
$digit = (int)( array_shift( $digits ) );
// consider this a sequence if this digit is one more than the last (or if
// there is no last digit) and if the following digit is sequential
return ( ( $last === '' ) || ( $digit === ( $last + 1) ) )
&& is_seq( $digits, $digit );
}