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Access lapply index names inside FUN
...ke function(x){parent.frame()$i+0} or function(x){--parent.frame()$i}.
Performance Impact
Will the forced duplication cause performance loss? Yes! here are the benchmarks:
> x <- as.list(seq_len(1e6))
> system.time( y <- lapply(x, function(x){parent.frame()$i[]}) )
user system elapse...
Simple example of threading in C++
...h execution, therefore blocks its own execution.
t1.join();
}
More information about std::thread here
On GCC, compile with -std=c++0x -pthread.
This should work for any operating-system, granted your compiler supports this (C++11) feature.
...
Getting full URL of action in ASP.NET MVC [duplicate]
...script which is beneficial in many situations.
UPDATE: The way to get url formed outside of the page itself is well described in answers above.
Or you could do a oneliner like following:
new UrlHelper(actionExecutingContext.RequestContext).Action(
"SessionTimeout", "Home",
new {area = s...
Why java.util.Optional is not Serializable, how to serialize the object with such fields
...ion related problems can be solved by decoupling the persistent serialized form from the actual runtime implementation you operate on.
/** The class you work with in your runtime */
public class My implements Serializable {
private static final long serialVersionUID = 1L;
Optional<Integ...
Ruby on Rails: Where to define global constants?
...rds immutable objects on your class boundary in Ruby and (2) you keep a uniform interface on your class with the possibility to adapt the return value later based on inherent state (e.g. by reading the colours from the DB) without changing the interface.
– Holger Just
...
In Javascript/jQuery what does (e) mean?
...ts methods, "e.preventDefault()", which should prevent the browser from performing the default action for that element.
Note: The handle can pretty much be named anything you want (i.e. 'function(billybob)'). The 'e' stands for 'event', which seems to be pretty standard for this type of function.
...
How can I pass data from Flask to JavaScript in a template?
My app makes a call to an API that returns a dictionary. I want to pass information from this dict to JavaScript in the view. I am using the Google Maps API in the JS, specifically, so I'd like to pass it a list of tuples with the long/lat information. I know that render_template will pass these ...
What's the difference between the data structure Tree and Graph?
...
A Tree is just a restricted form of a Graph.
Trees have direction (parent / child relationships) and don't contain cycles.
They fit with in the category of Directed Acyclic Graphs (or a DAG).
So Trees are DAGs with the restriction that a child can onl...
What programming practice that you once liked have you since changed your mind about? [closed]
...
Hungarian notation (both Forms and Systems).
I used to prefix everything. strSomeString or txtFoo.
Now I use someString and textBoxFoo. It's far more readable and easier for someone new to come along and pick up. As an added bonus, it's trivial to ke...
What is “vectorization”?
...term "vectorization" is also used to describe a higher level software transformation where you might just abstract away the loop altogether and just describe operating on arrays instead of the elements that comprise them)
The difference between vectorization and loop unrolling:
Consider the follo...