日本語と半角英数の間にスペースを挿入する

<pre class="wp-block-syntaxhighlighter-code">function add_space_full_width_half_width( $content ){
	//<pre>タグで分割
	$content_arr = preg_split('/(<pre\s*(?:"[^"]*"|\'[^\']*\'|[^\'">])*>.*?<\/pre>)/is', $content, -1, PREG_SPLIT_DELIM_CAPTURE);
	
	$content = '';
		
	foreach($content_arr as &$value){
		if(strpos($value,'<pre') === false){
		  //<>[]"'改行を除く半角英数字と隣り合ってるとき狭いスペースを挿入、タグの接するときはタグを覗いたパターンで判断
		  $content .= preg_replace( array( '/(?<![!-~\s]|^)((?:<("[^"]*"|\'[^\']*\'|[^\'">])*>)*)(?=[!#-&(-;=-Z\\\-~])/', '/(?<=[!#-&(-=?-\\\^-~])((?:<\/[a-zA-Z0-9]+>)*)(?![!-~\s]|$)/', '/(?<![!-~\s]) +(?=[!-~])/', '/(?<=[!-~]) +(?![!-~\s])/' ) , array( ' $1', '$1 ', ' ', ' ' ) , $value );
			} else {
			$content .= $value;
		}
	}
	
	return $content;
}
add_filter( 'the_content', 'add_space_full_width_half_width', 5);
add_filter( 'comment_text' , 'add_space_full_width_half_width', 5 );
add_filter( 'the_title' , 'add_space_full_width_half_width', 5 );</pre>