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What's the (hidden) cost of Scala's lazy val?
...he following Java code:
class LazyTest {
public int bitmap$0;
private String msg;
public String msg() {
if ((bitmap$0 & 1) == 0) {
synchronized (this) {
if ((bitmap$0 & 1) == 0) {
synchronized (this) {
msg = "Lazy";
...
How to list all functions in a Python module?
... @jAckOdE Quoted? Then you'll get available methods and attributes of the string module.
– OrangeTux
May 6 '14 at 7:44
...
What is a NullPointerException, and how do I fix it?
...your code can help avoid null pointer exception. eg when checking an input string with a constant string you should start with the constant string like here: if ("SomeString".equals(inputString)) {} //even if inputString is null no exception is thrown. So there are a bunch of things that you can do ...
How to center a (background) image within a div?
... If you want the entire div to be filled with the image and no extra space you should use background-size: cover; If you want the entire image to show without any part of the image being cut off or stretched you want to use background-size: contain;
– Zlerp
...
SQLAlchemy: Creating vs. Reusing a Session
... of expire_on_commit pretty much optional, as this flag can incur a lot of extra SQL for an operation that calls commit() in the middle of a series of operations. Not sure if this answers your question.
The next round is what you mention about threading. If your app is multithreaded, we recomme...
Copy a file in a sane, safe and efficient way
...; src.rdbuf();
}
This is so simple and intuitive to read it is worth the extra cost. If we were doing it a lot, better to fall back on OS calls to the file system. I am sure boost has a copy file method in its filesystem class.
There is a C method for interacting with the file system:
#include ...
Specify format for input arguments argparse python
...rsions to be performed ... type= can take any callable that takes a single string argument and returns the converted value
You could do something like:
def valid_date(s):
try:
return datetime.strptime(s, "%Y-%m-%d")
except ValueError:
msg = "Not a valid date: '{0}'.".forma...
Match multiple cases classes in scala
...
Looks like you don't care about the values of the String parameters, and want to treat B and C the same, so:
def matcher(l: Foo): String = {
l match {
case A() => "A"
case B(_) | C(_) => "B"
case _ => "default"
}
}
If you must, must, must extract ...
Which is more efficient: Multiple MySQL tables or one large table?
...ow on top of a legacy system. I had to expand the old database tables with extra columns. I decided to make new tables for the new data. Some new features come in handy for the legacy system and now I can easily integrate them without having to rewrite too much of the old queries
...
Use of var keyword in C#
...e is
incredibly ugly because of all the
redundancy:
Dictionary<string, List<int>> mylists = new Dictionary<string, List<int>>();
And that's a simple example – I've
written worse. Any time you're forced
to type exactly the same thing twice,
that's a redun...