fn __zero_std_inet_ipv4_core(text: Span<u8>) -> u64 {
    let len: usize = std.mem.len(text)
    var pos: usize = 0
    var octet_index: usize = 0
    var value: u32 = 0
    while octet_index < 4 {
        if pos >= len {
            return 0
        }
        var digits: usize = 0
        var octet: u32 = 0
        var leading_zero: Bool = false
        while pos < len && (text[pos] >= 48_u8 && text[pos] <= 57_u8) {
            if digits == 0 && text[pos] == 48_u8 {
                leading_zero = true
            }
            if digits >= 3 {
                return 0
            }
            octet = octet * 10_u32 + ((text[pos] - 48_u8) as u32)
            digits = digits + 1
            pos = pos + 1
        }
        if digits == 0 || octet > 255_u32 {
            return 0
        }
        if leading_zero && digits > 1 {
            return 0
        }
        value = value * 256_u32 + octet
        octet_index = octet_index + 1
        if octet_index < 4 {
            if pos >= len || text[pos] != 46_u8 {
                return 0
            }
            pos = pos + 1
        }
    }
    if pos != len {
        return 0
    }
    return 4294967296_u64 + (value as u64)
}

fn __zero_std_inet_parse_ipv4(text: Span<u8>) -> Maybe<u32> {
    let core: u64 = __zero_std_inet_ipv4_core(text)
    if core == 0 {
        return null
    }
    return (core % 4294967296_u64) as u32
}

fn __zero_std_inet_ipv4_to_bytes(buffer: MutSpan<u8>, value: u32) -> Maybe<Span<u8>> {
    if std.mem.len(buffer) < 4 {
        return null
    }
    buffer[0] = (value / 16777216_u32) as u8
    buffer[1] = ((value / 65536_u32) % 256_u32) as u8
    buffer[2] = ((value / 256_u32) % 256_u32) as u8
    buffer[3] = (value % 256_u32) as u8
    return buffer[..4]
}

fn __zero_std_inet_write_ipv4(buffer: MutSpan<u8>, value: u32) -> Maybe<Span<u8>> {
    var writer: FixedWriter = std.io.fixedWriter(buffer, 0_usize)
    let a: u32 = value / 16777216_u32
    let b: u32 = (value / 65536_u32) % 256_u32
    let c: u32 = (value / 256_u32) % 256_u32
    let d: u32 = value % 256_u32
    if std.fmt.writeU32(&mut writer, a) && (std.io.fixedWriterWriteByte(&mut writer, 46_u8) && std.fmt.writeU32(&mut writer, b)) && (std.io.fixedWriterWriteByte(&mut writer, 46_u8) && std.fmt.writeU32(&mut writer, c)) && (std.io.fixedWriterWriteByte(&mut writer, 46_u8) && std.fmt.writeU32(&mut writer, d)) {
        return std.io.fixedWriterView(&writer)
    }
    return null
}

fn __zero_std_inet_is_ipv4(text: Span<u8>) -> Bool {
    return __zero_std_inet_ipv4_core(text) != 0
}

fn __zero_std_inet_is_ipv4_unspecified(value: u32) -> Bool {
    return value == 0_u32
}

fn __zero_std_inet_is_ipv4_loopback(value: u32) -> Bool {
    return value / 16777216_u32 == 127_u32
}

fn __zero_std_inet_is_ipv4_private(value: u32) -> Bool {
    let first: u32 = value / 16777216_u32
    let second: u32 = (value / 65536_u32) % 256_u32
    if first == 10_u32 {
        return true
    }
    if first == 172_u32 && (second >= 16_u32 && second <= 31_u32) {
        return true
    }
    return first == 192_u32 && second == 168_u32
}

fn __zero_std_inet_is_ipv4_link_local(value: u32) -> Bool {
    let first: u32 = value / 16777216_u32
    let second: u32 = (value / 65536_u32) % 256_u32
    return first == 169_u32 && second == 254_u32
}

fn __zero_std_inet_is_ipv4_multicast(value: u32) -> Bool {
    let first: u32 = value / 16777216_u32
    return first >= 224_u32 && first <= 239_u32
}

fn __zero_std_inet_hex_value(byte: u8) -> u32 {
    if byte >= 48_u8 && byte <= 57_u8 {
        return (byte - 48_u8) as u32
    }
    if byte >= 97_u8 && byte <= 102_u8 {
        return (byte - 87_u8) as u32
    }
    if byte >= 65_u8 && byte <= 70_u8 {
        return (byte - 55_u8) as u32
    }
    return 4294967295_u32
}

fn __zero_std_inet_parse_ipv6(buffer: MutSpan<u8>, text: Span<u8>) -> Maybe<Span<u8>> {
    if std.mem.len(buffer) < 16 {
        return null
    }
    let len: usize = std.mem.len(text)
    if len == 0 {
        return null
    }
    var head: [8]u32 = [0; 8]
    var tail: [8]u32 = [0; 8]
    var head_count: usize = 0
    var tail_count: usize = 0
    var seen_gap: Bool = false
    var pos: usize = 0
    if text[0] == 58_u8 {
        if len < 2 || text[1] != 58_u8 {
            return null
        }
        seen_gap = true
        pos = 2
    }
    while pos < len {
        var token_end: usize = pos
        var has_dot: Bool = false
        while token_end < len && text[token_end] != 58_u8 {
            if text[token_end] == 46_u8 {
                has_dot = true
            }
            token_end = token_end + 1
        }
        if token_end == pos {
            return null
        }
        if has_dot {
            if token_end != len {
                return null
            }
            let v4: u64 = __zero_std_inet_ipv4_core(text[pos..len])
            if v4 == 0 {
                return null
            }
            let quad: u32 = (v4 % 4294967296_u64) as u32
            if seen_gap {
                if tail_count + 2 > 8 {
                    return null
                }
                tail[tail_count] = quad / 65536_u32
                tail[tail_count + 1] = quad % 65536_u32
                tail_count = tail_count + 2
            } else {
                if head_count + 2 > 8 {
                    return null
                }
                head[head_count] = quad / 65536_u32
                head[head_count + 1] = quad % 65536_u32
                head_count = head_count + 2
            }
            pos = len
            break
        }
        if token_end - pos > 4 {
            return null
        }
        var group: u32 = 0
        var scan: usize = pos
        while scan < token_end {
            let digit: u32 = __zero_std_inet_hex_value(text[scan])
            if digit == 4294967295_u32 {
                return null
            }
            group = group * 16_u32 + digit
            scan = scan + 1
        }
        if seen_gap {
            if tail_count + 1 > 8 {
                return null
            }
            tail[tail_count] = group
            tail_count = tail_count + 1
        } else {
            if head_count + 1 > 8 {
                return null
            }
            head[head_count] = group
            head_count = head_count + 1
        }
        pos = token_end
        if pos < len {
            pos = pos + 1
            if pos < len && text[pos] == 58_u8 {
                if seen_gap {
                    return null
                }
                seen_gap = true
                pos = pos + 1
                if pos == len {
                    break
                }
            } else if pos == len {
                return null
            }
        }
    }
    let total: usize = head_count + tail_count
    if seen_gap {
        if total > 7 {
            return null
        }
    } else {
        if total != 8 {
            return null
        }
    }
    var groups: [8]u32 = [0; 8]
    var index: usize = 0
    while index < head_count {
        groups[index] = head[index]
        index = index + 1
    }
    var tail_index: usize = 0
    while tail_index < tail_count {
        groups[8 - tail_count + tail_index] = tail[tail_index]
        tail_index = tail_index + 1
    }
    var out_index: usize = 0
    while out_index < 8 {
        buffer[out_index * 2] = (groups[out_index] / 256_u32) as u8
        buffer[out_index * 2 + 1] = (groups[out_index] % 256_u32) as u8
        out_index = out_index + 1
    }
    return buffer[..16]
}

fn __zero_std_inet_is_ipv6(text: Span<u8>) -> Bool {
    var storage: [16]u8 = [0; 16]
    let buffer: MutSpan<u8> = storage
    let parsed: Maybe<Span<u8>> = __zero_std_inet_parse_ipv6(buffer, text)
    return parsed.has
}

fn __zero_std_inet_is_ip(text: Span<u8>) -> Bool {
    return __zero_std_inet_is_ipv4(text) || __zero_std_inet_is_ipv6(text)
}

fn __zero_std_inet_parse_ip(buffer: MutSpan<u8>, text: Span<u8>) -> Maybe<Span<u8>> {
    let ipv4: Maybe<u32> = __zero_std_inet_parse_ipv4(text)
    if ipv4.has {
        return __zero_std_inet_ipv4_to_bytes(buffer, ipv4.value)
    }
    return __zero_std_inet_parse_ipv6(buffer, text)
}

fn __zero_std_inet_is_ipv6_unspecified(bytes: Span<u8>) -> Bool {
    if std.mem.len(bytes) != 16 {
        return false
    }
    var index: usize = 0
    while index < 16 {
        if bytes[index] != 0_u8 {
            return false
        }
        index = index + 1
    }
    return true
}

fn __zero_std_inet_is_ipv6_loopback(bytes: Span<u8>) -> Bool {
    if std.mem.len(bytes) != 16 {
        return false
    }
    var index: usize = 0
    while index < 15 {
        if bytes[index] != 0_u8 {
            return false
        }
        index = index + 1
    }
    return bytes[15] == 1_u8
}

fn __zero_std_inet_is_ipv6_multicast(bytes: Span<u8>) -> Bool {
    return std.mem.len(bytes) == 16 && bytes[0] == 255_u8
}

fn __zero_std_inet_is_ipv6_link_local(bytes: Span<u8>) -> Bool {
    return std.mem.len(bytes) == 16 && (bytes[0] == 254_u8 && (bytes[1] >= 128_u8 && bytes[1] <= 191_u8))
}

fn __zero_std_inet_is_ipv6_private(bytes: Span<u8>) -> Bool {
    return std.mem.len(bytes) == 16 && (bytes[0] == 252_u8 || bytes[0] == 253_u8)
}

fn __zero_std_inet_is_ipv6_unique_local(bytes: Span<u8>) -> Bool {
    return __zero_std_inet_is_ipv6_private(bytes)
}

fn __zero_std_inet_is_ipv6_mapped_ipv4(bytes: Span<u8>) -> Bool {
    if std.mem.len(bytes) != 16 {
        return false
    }
    var index: usize = 0
    while index < 10 {
        if bytes[index] != 0_u8 {
            return false
        }
        index = index + 1
    }
    return bytes[10] == 255_u8 && bytes[11] == 255_u8
}

fn __zero_std_inet_ipv6_mapped_ipv4(bytes: Span<u8>) -> Maybe<u32> {
    if !__zero_std_inet_is_ipv6_mapped_ipv4(bytes) {
        return null
    }
    return (bytes[12] as u32) * 16777216_u32 + (bytes[13] as u32) * 65536_u32 + (bytes[14] as u32) * 256_u32 + (bytes[15] as u32)
}

fn __zero_std_inet_is_hostname(text: Span<u8>) -> Bool {
    let len: usize = std.mem.len(text)
    if len == 0 || len > 253 {
        return false
    }
    var pos: usize = 0
    var label_len: usize = 0
    while pos < len {
        let byte: u8 = text[pos]
        if byte == 46_u8 {
            if label_len == 0 {
                return false
            }
            if text[pos - 1] == 45_u8 {
                return false
            }
            label_len = 0
        } else {
            if label_len == 0 && byte == 45_u8 {
                return false
            }
            let is_alnum: Bool = (byte >= 48_u8 && byte <= 57_u8) || ((byte >= 65_u8 && byte <= 90_u8) || (byte >= 97_u8 && byte <= 122_u8))
            if !is_alnum && byte != 45_u8 {
                return false
            }
            label_len = label_len + 1
            if label_len > 63 {
                return false
            }
        }
        pos = pos + 1
    }
    if label_len == 0 {
        return false
    }
    return text[len - 1] != 45_u8
}