func getRegistryValue()

in windows/setupapi_windows.go [1123:1172]
50 lines of code
15 McCabe index (conditional complexity)

func getRegistryValue(buf []byte, dataType uint32) (interface{}, error) {
	switch dataType {
	case REG_SZ:
		ret := UTF16ToString(bufToUTF16(buf))
		runtime.KeepAlive(buf)
		return ret, nil
	case REG_EXPAND_SZ:
		value := UTF16ToString(bufToUTF16(buf))
		if value == "" {
			return "", nil
		}
		p, err := syscall.UTF16PtrFromString(value)
		if err != nil {
			return "", err
		}
		ret := make([]uint16, 100)
		for {
			n, err := ExpandEnvironmentStrings(p, &ret[0], uint32(len(ret)))
			if err != nil {
				return "", err
			}
			if n <= uint32(len(ret)) {
				return UTF16ToString(ret[:n]), nil
			}
			ret = make([]uint16, n)
		}
	case REG_BINARY:
		return buf, nil
	case REG_DWORD_LITTLE_ENDIAN:
		return binary.LittleEndian.Uint32(buf), nil
	case REG_DWORD_BIG_ENDIAN:
		return binary.BigEndian.Uint32(buf), nil
	case REG_MULTI_SZ:
		bufW := bufToUTF16(buf)
		a := []string{}
		for i := 0; i < len(bufW); {
			j := i + wcslen(bufW[i:])
			if i < j {
				a = append(a, UTF16ToString(bufW[i:j]))
			}
			i = j + 1
		}
		runtime.KeepAlive(buf)
		return a, nil
	case REG_QWORD_LITTLE_ENDIAN:
		return binary.LittleEndian.Uint64(buf), nil
	default:
		return nil, fmt.Errorf("Unsupported registry value type: %v", dataType)
	}
}