IRI::set_host( string|null $ihost ): bool

856    public function set_host(?string $ihost)857    {858        if ($ihost === null) {859            $this->ihost = null;860            return true;861        } elseif (substr($ihost, 0, 1) === '[' && substr($ihost, -1) === ']') {862            if (\SimplePie\Net\IPv6::check_ipv6(substr($ihost, 1, -1))) {863                $this->ihost = '[' . \SimplePie\Net\IPv6::compress(substr($ihost, 1, -1)) . ']';864            } else {865                $this->ihost = null;866                return false;867            }868        } else {869            $ihost = $this->replace_invalid_with_pct_encoding($ihost, '!$&\'()*+,;=');870 871            // Lowercase, but ignore pct-encoded sections (as they should872            // remain uppercase). This must be done after the previous step873            // as that can add unescaped characters.874            $position = 0;875            $strlen = strlen($ihost);876            while (($position += strcspn($ihost, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ%', $position)) < $strlen) {877                if ($ihost[$position] === '%') {878                    $position += 3;879                } else {880                    $ihost[$position] = strtolower($ihost[$position]);881                    $position++;882                }883            }884 885            $this->ihost = $ihost;886        }887 888        $this->scheme_normalization();889 890        return true;891    }