[Qt-interest] Organizing error message strings

[John Weeks]

Thank you, André.

On Apr 6, 2010, at 11:21 PM, André Somers wrote:

> Interesting question.
> IMHO, using a QMap (or better yet, a QHash) would be a reasonable  
> approach. I think you’ll just have to try if the initialization time  
> of a suitably large QMap or QHash would take too much time for you.  
> My guess would be that it is not an issue. You can speed up  
> initialization a bit by calling QHash::reserve. Why don’t you create  
> a small test to see how much time it actually takes to initialize a  
> QHash like that with 10,000 messages or so? A simple loop would give  
> you a rough estimate.

Hm. Good point. So I wrote a class to wrap the error messages that  
uses a QMap<int, QString>. The constructor looks like this:

ErrorStrings::ErrorStrings()
{
	messageMap.insert(1, tr("out of memory"));
	messageMap.insert(2, tr("expected wave name"));
	messageMap.insert(3, tr("syntax error"));
	messageMap.insert(4, tr("expected comma"));
	messageMap.insert(5, tr("expected name of active axis"));

etc.

There are almost 1319 strings. Using QTime to get the time required to  
run the constructor returns 1 mS, which is the resolution of  
QTime::elapsed(). So I guess my fears on that score were groundless!

QMap has no reserve() function. I suppose that's because it's based on  
a list structure rather than an array.

I'm still wondering if this is the Qt Way. Or maybe my application is  
unusual?

Regards,
John Weeks

WaveMetrics, Inc.
Phone (503) 620-3001
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