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In Functional Programming, what is a functor?
...fmap even
is an overloaded function that can do many wonderful things:
Convert a list of integers to a list of Booleans
Convert a tree of integers to a tree of Booleans
Convert Nothing to Nothing and Just 7 to Just False
In Haskell, this property is expressed by giving the type of fmap:
fmap ...
Select 50 items from list at random to write to file
... leaving the original population unchanged. The resulting list is
in selection order so that all sub-slices will also be valid random
samples. This allows raffle winners (the sample) to be partitioned
into grand prize and second place winners (the subslices).
Members of the popul...
Why would json_encode return an empty string
... problem, but see note below
Here is a recursive function that can force convert to UTF-8 all the strings contained in an array:
function utf8ize($d) {
if (is_array($d)) {
foreach ($d as $k => $v) {
$d[$k] = utf8ize($v);
}
} else if (is_string ($d)) {
...
Store select query's output in one array in postgres
...
There are two ways. One is to aggregate:
SELECT array_agg(column_name::TEXT)
FROM information.schema.columns
WHERE table_name = 'aean'
The other is to use an array constructor:
SELECT ARRAY(
SELECT column_name
FROM information.schema.columns
WHERE table_name = ...
How to change string into QString?
...
If compiled with STL compatibility, QString has a static method to convert a std::string to a QString:
std::string str = "abc";
QString qstr = QString::fromStdString(str);
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improve ...
Error when trying to obtain a certificate: The specified item could not be found in the keychain
...
I solved it. Ensure you are in the "Certificates" section and you select "Apple Worldwide Developer Relations Certification Authority" before requesting a certificate.
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Is there a Python equivalent to Ruby's string interpolation?
...nd text found in the example in the documentation however. Why the use of convert to string here: %(language)s What does the 3 in '03d' signify? Why after the string is there % \? The assignment of variables (if they are in fact variables) after the print expression confuses me also. Sorry if t...
Android Spinner : Avoid onItemSelected calls during initialization
...droid application with a Spinner and a TextView . I want to display the selected item from the Spinner's drop down list in the TextView. I implemented the Spinner in the onCreate method so when I'm running the program, it shows a value in the TextView (before selecting an item from the drop d...
How to assert two list contain the same elements in Python? [duplicate]
...
If there are only unique values in list Converting them to set using set(l1)& set(2) & asserting using assertSetEqual(l1, l2) also helps.
– Abhijeet
Jun 25 '18 at 8:34
...
JavaScript Editor Plugin for Eclipse [duplicate]
...ript files:
Open Eclipse -> Go to "Help" -> "Install New Software"
Select the repository for your version of Eclipse. I have Juno so I selected http://download.eclipse.org/releases/juno
Expand "Programming Languages" -> Check the box next to "JavaScript Development Tools"
Click "Next" -&g...