mb_strlen

<?php             case 'string':

                $this->type = self::TYPE_STRING;

                $this->class = preg_match('//u', $value) ? self::STRING_UTF8 : self::STRING_BINARY;

                $this->cut = self::STRING_BINARY === $this->class ? \strlen($value) : mb_strlen($value, 'UTF-8');

                $this->value = '';

                break;

        }

<?php                             } else {

                                $stub->value = $v;

                            }

                        } elseif (0 <= $maxString && isset($v[1 + ($maxString >> 2)]) && 0 < $cut = mb_strlen($v, 'UTF-8') - $maxString) {

                            $stub = new Stub();

                            $stub->type = Stub::TYPE_STRING;

                            $stub->class = Stub::STRING_UTF8;

<?php             $this->endValue($cursor);

        } else {

            $attr += [

                'length' => 0 <= $cut ? mb_strlen($str, 'UTF-8') + $cut : 0,

                'binary' => $bin,

            ];

            $str = $bin && false !== strpos($str, "\0") ? [$str] : explode("\n", $str);

<?php                 if ($i < $m) {

                    $str .= "\n";

                }

                if (0 < $this->maxStringWidth && $this->maxStringWidth < $len = mb_strlen($str, 'UTF-8')) {

                    $str = mb_substr($str, 0, $this->maxStringWidth, 'UTF-8');

                    $lineCut = $len - $this->maxStringWidth;

                }