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When should you NOT use a Rules Engine? [closed]
...s when I see people using very large rule sets (e.g., on the order of thousands of rules in a single rule set). This often happens when the rules engine is a singleton sitting in the center of the enterprise in the hope that keeping rules DRY will make them accessible to many apps that require them...
Uses for Optional
...eem to swing between wanting to use it everywhere something may be null , and nowhere at all.
14 Answers
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What is an idempotent operation?
...g that x in the mathematical definition represents the state of an object, and f is an operation that may mutate that object. For example, consider the Python set and its discard method. The discard method removes an element from a set, and does nothing if the element does not exist. So:
my_set.dis...
Stretch and scale CSS background
...
That would work for Safari 3 (or later), Chrome, Opera 10+, Firefox 3.6+, and Internet Explorer 9 (or later).
For it to work with lower verions of Internet Explorer, try these CSS:
filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(src='.myBackground.jpg', sizingMethod='scale');
-ms-fi...
Why does (i
... j is evaluated to true, because auto unboxing happens for int
comparisons and then both i and j hold the default value, 0.
j <= i is evaluated to true because of the above reason.
i != j is evaluated to true, because both i and j are
different objects. And while comparing objects, there isn't an...
Why should text files end with a newline?
...
Because that’s how the POSIX standard defines a line:
3.206 Line
A sequence of zero or more non- <newline> characters plus a terminating <newline> character.
Therefore, lines not ending in a newline character aren't considered act...
How can I check if a string represents an int, without using try/except?
... is an int, so does your program. If Python changes, so does your program, and without changing a single line of code. There's some value in that. It might be the right thing to do depending on the circumstances.
– Shavais
Oct 8 '14 at 16:07
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How to change users in TortoiseSVN
...atile method. First, locate it:
On XP, it was located here:
C:\Documents and Settings\%USER%\Application Data\Subversion\auth\svn.simple\
On Vista, it was located here:
C:\Users\%USER%\AppData\Roaming\Subversion\auth\svn.simple\
Then look in those files with Notepad, and delete the one with y...
What is the difference between .*? and .* regular expressions?
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It is the difference between greedy and non-greedy quantifiers.
Consider the input 101000000000100.
Using 1.*1, * is greedy - it will match all the way to the end, and then backtrack until it can match 1, leaving you with 1010000000001.
.*? is non-greedy. * w...
Proper practice for subclassing UIView?
I'm working on some custom UIView-based input controls, and I'm trying to ascertain proper practice for setting up the view. When working with a UIViewController, it's fairly simple to use the loadView and related viewWill , viewDid methods, but when subclassing a UIView, the closest methosds I...