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When do you use map vs flatMap in RxJava?
...ten" this observable of observables (you might start to see where the name _flat_Map comes from). RxJava provides a few ways to flatten observables and for sake of simplicity lets assume merge is what we want. Merge basically takes a bunch of observables and emits whenever any of them emits. (Lots o...
Which is faster: Stack allocation or Heap allocation
...pty classes take up 1 byte of space, minimum
}
int main()
{
std::clock_t start = std::clock();
for (int i = 0; i < 100000; ++i)
empty e;
std::clock_t duration = std::clock() - start;
std::cout << "stack allocation took " << duration << " clock ticks\n";
...
live output from subprocess command
...: # replace 'w' with 'wb' for Python 3
process = subprocess.Popen(your_command, stdout=subprocess.PIPE)
for c in iter(lambda: process.stdout.read(1), ''): # replace '' with b'' for Python 3
sys.stdout.write(c)
f.write(c)
or
import subprocess
import sys
with open('test.lo...
What is a message pump?
...s as or is perceived as a single separate object encarta.msn.com/dictionary_1861608661/entity.html
– Matthew Whited
Feb 8 '10 at 16:23
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In Firebase, is there a way to get the number of children of a node without loading all the node dat
...ts/-JRHTHaIs-jNPLXOQivY/upvotes');
upvotesRef.transaction(function (current_value) {
return (current_value || 0) + 1;
});
For more info, see https://www.firebase.com/docs/transactions.html
UPDATE:
Firebase recently released Cloud Functions. With Cloud Functions, you don't need to create your ow...
What is “entropy and information gain”?
.... P(m)=9/14 and P(f)=5/14. According to the definition of entropy:
Entropy_before = - (5/14)*log2(5/14) - (9/14)*log2(9/14) = 0.9403
Next we compare it with the entropy computed after considering the split by looking at two child branches. In the left branch of ends-vowel=1, we have:
Entropy_lef...
ASP.NET MVC HandleError
..., logMessage, filterContext);
logDirectory = (logDirectory + "\\Log_" + LogFileName(DateTime.Now) + ".txt");
StreamWriter streamWriter = null;
try
{
streamWriter = new StreamWriter(logDirectory, true);
streamWriter.WriteLine(logLine);
...
What does an exclamation mark mean in the Swift language?
...://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/TheBasics.html#//apple_ref/doc/uid/TP40014097-CH5-XID_399
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Are memory leaks ever ok? [closed]
...responding free. An easy way to make one is like this:
#define BLK ((size_t)1024)
while(1){
void * vp = malloc(BLK);
}
Note that every time around the while(1) loop, 1024 (+overhead) bytes are allocated, and the new address assigned to vp; there's no remaining pointer to the previous malloc'...
What's the difference between a catalog and a schema in a relational database?
...pper wrapper" object before the database itself.
I mean DB.schema.<what_ever_object_name_under_schema> .
2 Answers
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