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Haskell Type vs Data Constructor
...erstanding type constructors and data constructors. For example, I don't really understand the difference between this:
6 A...
OceanBase使用libeasy原理源码分析：客户端 - 数据库(内核) - 清泛网 - 专...
...端》，作为客户端使用时，会涉及到一些数据结构，easy_session_t, easy_client_t, easy_hash_t, easy_hash_list_t等。
easy_session_t用来封装一个要发出去的请求，easy_client_t用来封装一个TCP连接的发起端，easy_hash_t是一个哈希表，easy_hash_list_t是...
List all tables in postgresql information_schema
What is the best way to list all of the tables within PostgreSQL's information_schema?
8 Answers
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Performance of foreach, array_map with lambda and array_map with static function
...
}
return $result;
}
function useMapClosure($numbers) {
return array_map(function($number) {
return $number * 10;
}, $numbers);
}
function _tenTimes($number) {
return $number * 10;
}
function useMapNamed($numbers) {
return array_map('_tenTimes', $numbers);
}
foreach (array('F...
Why does `a == b or c or d` always evaluate to True?
...r is more literal minded.
if name == "Kevin" or "Jon" or "Inbar":
is logically equivalent to:
if (name == "Kevin") or ("Jon") or ("Inbar"):
Which, for user Bob, is equivalent to:
if (False) or ("Jon") or ("Inbar"):
The or operator chooses the first argument with a positive truth value:
if ("Jon")...
Setting environment variables for accessing in PHP when using Apache
I have a Linux environment and I have a PHP Web Application that conditionally runs based on environment variables using getenv in PHP. I need to know how these environment variables need to be set for the application to work correctly. I am not sure how to set this up on Apache.
...
Combine --user with --prefix error with setup.py install
...me workaround:
pip install --user --install-option="--prefix=" <package_name>
or
python setup.py install --user --prefix=
Note that there is no text (not even whitespace) after the =.
Do not forget the --user flag.
Installing multiple packages:
Create ~/.pydistutils.cfg (or equivalent...
Can I list-initialize a vector of move-only type?
...nitializer list elements in the current revision of the language.
Specifically, we have:
typedef const E& reference;
typedef const E& const_reference;
typedef const E* iterator;
typedef const E* const_iterator;
const E* begin() const noexcept; // first element
const E* end() const noexce...
How to launch jQuery Fancybox on page load?
..."text/javascript">
$(document).ready(function() {
$("#hidden_link").fancybox().trigger('click');
});
</script>
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Nullable Foreign Key bad practice?
... read.
Only if you know better than Chris Date "what first normal form really means". If x and y are both nullable, and indeed in some row x and y are both null, then WHERE x=y does not yield true. This proves beyond reasonable doubt that null is not a value (because any real value is always equ...