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Match whitespace but not newlines
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Perl versions 5.10 and later support subsidiary vertical and horizontal character classes, \v and \h, as well as the generic whitespace character class \s
The cleanest solution is to use the horizontal whitespace character class \h. This will ...
How does the Amazon Recommendation feature work?
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It is both an art and a science. Typical fields of study revolve around market basket analysis (also called affinity analysis) which is a subset of the field of data mining. Typical components in such a system include identification of prima...
Why use pointers? [closed]
...tionality, missing data types or for pure perfomance. More below...
When and where should I use pointers?
Short answer here is: Where you cannot use anything else. In C you don't have any support for complex datatypes such as a string. There are also no way of passing a variable "by reference" ...
Save PL/pgSQL output from PostgreSQL to a CSV file
...ing easy to re-use or automate, you can use Postgresql's built in COPY command. e.g.
Copy (Select * From foo) To '/tmp/test.csv' With CSV DELIMITER ',' HEADER;
This approach runs entirely on the remote server - it can't write to your local PC. It also needs to be run as a Postgres "superuser" (no...
How to put multiple statements in one line?
...t is not possible with Python (which makes Python close to useless for command-line one-liner programs). Even explicit use of parentheses does not avoid the syntax exception. You can get away with a sequence of simple statements, separated by semi-colon:
for i in range(10): print "foo"; print "bar"...
What is the difference between a definition and a declaration?
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A declaration introduces an identifier and describes its type, be it a type, object, or function. A declaration is what the compiler needs to accept references to that identifier. These are declarations:
extern int bar;
extern int g(int, int);
double f(int, doub...
Connect Java to a MySQL database
...(DataSource) context.lookup("java:comp/env/jdbc/myDB");
or instantiating and configuring one from your database driver directly:
MysqlDataSource dataSource = new MysqlDataSource();
dataSource.setUser("scott");
dataSource.setPassword("tiger");
dataSource.setServerName("myDBHost.example.org");
an...
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...
Working with $scope.$emit and $scope.$on
...an I send my $scope object from one controller to another using .$emit and .$on methods?
12 Answers
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Why is it impossible to build a compiler that can determine if a C++ function will change the value
...er any given program will terminate. This is known as the halting problem, and it's one of those things that's not computable.
To be clear, you can write a compiler that can determine that a function does change the variable in some cases, but you can't write one that reliably tells you that the fu...