<?php
function do_split($name) {
return preg_split('/([A-Z]{2,}|([A-Z][^A-Z]*))/', $name, null, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);
}
function convert_case($name) {
return implode(
'_',
array_map(
'strtolower',
do_split($name)
)
);
}
function convert_case2($in) {
$len = strlen($in);
if ($len < 2) {
return strtolower($in);
}
$pos = 0;
$out = '';
$peek = function() use ($in, $pos, $len) {
if ($pos+1 >= $len) {
return null;
}
return $in[$pos+1];
};
$next = function() use ($peek, &$pos) {
$c = $peek();
if ($c === null) {
return null;
}
$pos++;
return $c;
};
$upper = function ($c) {
return 'A' <= $c && $c <= 'Z';
};
$lower = function ($c) {
return 'a' <= $c && $c <= 'z';
};
$alpha = function ($c) use ($upper, $lower) {
return $upper($c) || $lower($c);
};
$num = function ($c) {
return '0' <= $c && $c <= '9';
};
$alpha_num = function ($c) use ($alpha, $num) {
return $alpha($c) || $num($c);
};
$start_state = function () use (&$out, $next, $peek) {
for ($c = $next(); $c !== null; $c = $next()) {
$out .= $c;
}
return null;
};
$state = $start_state;
while ($state !== null) {
$state = $state();
}
return strtolower($out);
}
convert_case2('FooBARbar0123');
$samples = array(
'FooBar',
'FooBAR',
'FOOBar',
'foo_bar',
'FOO_bar',
'FOO_Bar',
'foo_BAR',
'foo_Bar',
'Foo_bar',
);
print_r(array_map(function ($name) {
return array(
'name' => $name,
'converted' => convert_case2($name),
// 'converted' => convert_case($name),
);
}, $samples));
preferences:
38.94 ms | 402 KiB | 5 Q