On Wed, Aug 31, 2011 at 11:27 AM, Peter Brinkmann
<peter.brinkmann@googlemail.com> wrote:
On Aug 31, 2011, at 8:45 AM, Peter Brinkmann wrote:
On Wed, Aug 31, 2011 at 6:25 AM, Dan Wilcox <danomatika@gmail.com> wrote:
I think it's much simpler to just add a call to get/set the message limit, say:
int libpd_max_message_length();
void libpd_set_max_message_length(int length);
This doesn't break any current code.
Having to set a custom limit each time is far more tedious then just setting it at startup.
Actually, breakage of current code is a feature as far as I am concerned because it makes people aware of the change, and it should be harmless because it's easy to fix. The language bindings for Java and Objective-C actually became simpler when I updated them for the new version.
I don't think the new signature of libpd_start_message is tedious, really. Essentially, I see two use cases: Either you know an a-priori limit on your message length, in which case there's the tiny extra effort of passing in the limit every time you start a message, or you don't have an a-priori limit, in which case you need to check the length before assembling a message anyway.
Another aspect is API design. One feature of a good API is that it's difficult to use incorrectly. With a separate call for setting the message limit, people will forget that the limit is a consideration. With the current solution, people will briefly contemplate the length of each message they start, which is a good thing.
... but you can simply return an error or print a message complaining when the message is too long. My whole point is that most people won't bother changing the limit and those that do will just pick a larger size with plenty of space anyway. It's too much work to bother setting it EACH and EVERY time. It's far LESS elegant, and dare I say intuitive. It seems like an unnecessary step. [eople that have problems will only run into this once, increase the max size, and then be fine. Why force them to compute a size manually each time when they could just be happily adding objects ... ?
Actually, I don't mean to make people compute the size every time The length parameter in libpd_start_message merely makes sure that you'll have enough space for that many elements; the number of elements in the actual message may be smaller. If you know that your messages will never exceed a certain length, then you can simply use that maximum length every time. In that situation, I would just wrap the call to libpd_start_message in a macro or a convenience function to get exactly the effect that you want.
By the way, there's also a third way between specifying the max size every time and creating a convenience function. The start message function will only allocate new memory if the requested size is larger than what was requested before. You can also say libpd_start_message(MAX_SIZE) right after you initialize libpd, and then start all messages with libpd_start_message(0), where 0 means that it'll just use whatever was allocated before. This is convenient, but it doesn't quite look right to me, so I'd probably still go with convenience functions.
Peter