wp-includes/class-wp-editor.php:835$initarraystring private static function _parse_init( $init ) { $options = ''; foreach ( $init as $key => $value ) { if ( is_bool( $value ) ) { $val = $value ? 'true' : 'false'; $options .= $key . ':' . $val . ','; continue; } elseif ( ! empty( $value ) && is_string( $value ) && ( ( '{' === $value[0] && '}' === $value[ strlen( $value ) - 1 ] ) || ( '[' === $value[0] && ']' === $value[ strlen( $value ) - 1 ] ) || preg_match( '/^\(?function ?\(/', $value ) ) ) { $options .= $key . ':' . $value . ','; continue; } $options .= $key . ':"' . $value . '",'; } return '{' . trim( $options, ' ,' ) . '}'; }Introduced in 3.3.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-editor.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.