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Where does the “flatmap that s***” idiomatic expression in Scala come from?
What is so powerful about flatmap that it deserves such a place in the Scala folklore?
4 Answers
...
Listing all permutations of a string/integer
...sk in programming interviews (not from my experience of interviews though) is to take a string or an integer and list every possible permutation.
...
ExecuteReader requires an open and available Connection. The connection's current state is Connectin
...ce it seems to be faster than to create a new object for any action.
That is neither a good idea in terms of peformance nor in terms of fail-safety.
Don't poach on the Connection-Pool's territory
There's a good reason why ADO.NET internally manages the underlying Connections to the DBMS in the AD...
Linking R and Julia?
Julia looks very promising for fast and syntax-sane computation (e.g. here ), but I suspect it will not be anywhere near R in terms of overall statistics workflow for some time yet. So I'd like to use it where C++ is mainly used in R programs: to optimize slow portions of code. Before I invest th...
Does C have a “foreach” loop construct?
... macros are frequently used to emulate that:
#define for_each_item(item, list) \
for(T * item = list->head; item != NULL; item = item->next)
And can be used like
for_each_item(i, processes) {
i->wakeup();
}
Iteration over an array is also possible:
#define foreach(item, array...
Can someone explain collection_select to me in clear, simple terms?
...thor.where(..).order(..) or something like that.
# In your example it is:
Author.all,
# then you should specify methods for generating options
:id, # this is name of method that will be called for every row, result will be set as key
:name_with_initial, # this is name of metho...
How do I call a JavaScript function on page load?
...nt the onload method to take parameters, you can do something similar to this:
window.onload = function() {
yourFunction(param1, param2);
};
This binds onload to an anonymous function, that when invoked, will run your desired function, with whatever parameters you give it. And, of course, you c...
how to stop Javascript forEach? [duplicate]
...ent in deep comments nesting with recursive function and forEach within. Is there a way to stop Node.js forEach ? As I understand every forEach iteration is a function and and I can't just do break , only return but this won't stop forEach .
...
Static extension methods [duplicate]
Is there any way I can add a static extension method to a class.
4 Answers
4
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Is mongodb running?
...ngoDB version >= 2.6
or
service mongod status
to see if mongod is running (you need to be root to do this, or prefix everything with sudo). Please note that the 'grep' command will always also show up as a separate process.
check the log file /var/log/mongo/mongo.log to see if there ar...