Cool test for between-ness
September 24, 2006 on 11:43 pm | In .NET Coding |I traditionally hated testing for between-ness, because I had to order the endpoints. Like to determine if x was between y and z I had to make sure that y and z were arranged in the right order and then do if x < z and x > y then return true. Well I found a better way now that allows me not to care:
// tests to see if x is between y and z (inclusively)
public bool IsBetweenIncl(IComparable x, IComparable y, IComparable z)
{
int a = x.CompareTo(y);
int b = x.CompareTo(z);
if ( (a >= 0) != (b >= 0))
return true;
return false;
}
// tests to see if x is between y and z (exclusively)
public bool IsBetweenExcl(IComparable x, IComparable y, IComparable z)
{
int a = x.CompareTo(y);
int b = x.CompareTo(z);
if ((a > 0) != (b > 0) )
return true;
return false;
}
Not earth shatterning, but it’s things like this that keep me sane when I’m writing the compiler. Yes I know there are more terse ways of writing that same stuff, but this is an illustration.
Here’s the ‘production’ versions of the same code without their illustrative qualities:
public bool IsBetweenIncl(IComparable x, IComparable y, IComparable z)
{
return ( (x.CompareTo(y) >= 0) != (x.CompareTo(z) >= 0));
}
public bool IsBetweenExcl(IComparable x, IComparable y, IComparable z)
{
return ((x.CompareTo(y) > 0) != (x.CompareTo(z) > 0));
}
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I noticed you’ve been updating the code, but if I’m reading SourceForge correctly, none of your updates to RefGen have made it into that code. Do you have a timeframe for when that might happen?
Thanks in advance.
Comment by SourceForge Project — September 25, 2006 #
Actually I’ve updated the code quite a bit, just the ObjectDataSource stuff isn’t in there yet. I didn’t want to put it in until I’d tested it some more. It looks like it is ok now, so probably in a day or two. I’ll update it here on this page as well as in refgen
Comment by Dave — September 25, 2006 #
Its up now.
Comment by Dave — September 26, 2006 #