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Traverse a list in reverse order in Python
... are reversed on the fly while traversing! This is an important feature of all these iteration functions (which all end on “ed”).
– Konrad Rudolph
Feb 9 '09 at 19:10
9
...
Accessing UI (Main) Thread safely in WPF
... example:
class MyViewModel
{
private readonly SynchronizationContext _syncContext;
public MyViewModel()
{
// we assume this ctor is called from the UI thread!
_syncContext = SynchronizationContext.Current;
}
// ...
private void watcher_Changed(object send...
How do I check if a variable exists?
...have nested functions, variables in outer scopes. If you want to check for all of them, you're probably best off triggering NameError after all.
– Petr Viktorin
Jun 10 '14 at 20:18
...
What does “coalgebra” mean in the context of programming?
...coalgebras" several times in functional programming and PLT circles, especially when the discussion is about objects, comonads, lenses, and such. Googling this term gives pages that give mathematical description of these structures which is pretty much incomprehensible to me. Can anyone please expla...
不同品牌的防火墙组成高可靠性集群 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...编号越小优先级越高。例如如下路由规则：
0: from all lookup local
32766: from all lookup main
32767: from all lookup default
优先级最高的规则是0，要查询的路由表名称是local，其次是32766，要查询的路由表名称是main，后面依此...
Unicode与UTF-8互转(C语言实现) - C/C++ - 清泛网 - 专注C/C++及内核技术
...***************************************************************/
int enc_unicode_to_utf8_one(unsigned long unic, unsigned char *pOutput,
int outSize)
{
assert(pOutput != NULL);
assert(outSize >= 6);
if ( unic <= 0x0000007F )
{
// * U-000000...
What do commas and spaces in multiple classes mean in CSS?
..._12 .grid_6,
.container_16 .grid_8 {
width: 460px;
}
That says "make all .grid_6's within .container_12's and all .grid_8's within .container_16's 460 pixels wide." So both of the following will render the same:
<div class="container_12">
<div class="grid_6">460px Wide</div&g...
Order data frame rows according to vector with specific order
...
I prefer to use ***_join in dplyr whenever I need to match data. One possible try for this
left_join(data.frame(name=target),df,by="name")
Note that the input for ***_join require tbls or data.frame
...
Storing R.drawable IDs in XML array
...encoding="utf-8"?>
<resources>
<integer-array name="random_imgs">
<item>@drawable/car_01</item>
<item>@drawable/balloon_random_02</item>
<item>@drawable/dog_03</item>
</integer-array>
</resources>
Then...
Bash: infinite sleep (infinite blocking)
... "string" to a double. Then that double is truncated to the maximum values allowed timespec, which means a very large amount of seconds (architecture-dependant) but, in theory, finite.
– jp48
Aug 19 '17 at 11:16
...