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Functional programming - is immutability expensive? [closed]
...bvious disadvantages of a functional quicksort implementation. In the following, let’s consider this reference implementation in Haskell (I don’t know Scala …) from the Haskell introduction:
qsort [] = []
qsort (x:xs) = qsort lesser ++ [x] ++ qsort greater
where lesser = (filter (<...
Is Python strongly typed?
...design choice made when + was implemented, but not really a necessity following from the language's semantics. In fact, when you overload + on a custom type, you can make it implicitly convert anything to a number:
def to_number(x):
"""Try to convert function argument to float-type object."""
...
What is in your Mathematica tool bag? [closed]
... of images under these operations, i.e. they're equivalent, using the following
In[3] := SelectEquivalents[ pts, Union[Through[rots[#] ] ]& ] (*<-- Note Union*)
Out[3]:= {{{-1, -1, 0}, {-1, 1, 0}, {1, -1, 0}, {1, 1, 0}},
{{-1, 0, 0}, {0, -1, 0}, {0, 1, 0}, {1, 0, 0}},
{{0...
Java “Virtual Machine” vs. Python “Interpreter” parlance?
...
@S.Lott Because it's always good to win arguments with colleagues. ;)
– Qix - MONICA WAS MISTREATED
Oct 6 '14 at 3:50
...
What does O(log n) mean exactly?
...t's versatile as an example. Plus I got to use robots in my explanation! A win all-around. (Also, it looks like your answer was made before I was even a member on StackOverflow to begin with!)
– John Feminella
Feb 23 '10 at 0:40
...
How to use git bisect?
...he history to find a particular regression. Imagine that you have the following development history:
... --- 0 --- 1 --- 2 --- 3 --- 4* --- 5 --- current
You know that your program is not working properly at the current revision, and that it was working at the revision 0. So the regression was li...
水果vs蔬菜智能分类器 - EdgeML图像识别项目 · App Inventor 2 中文网
...
价格查询: 识别商品后显示价格信息
清单管理: 自动生成购物清单
比价功能: 比较不同商店的价格
技术实现：
集成价格数据库
地理位置服务
条形码扫描
在线支付接口
4. 农业应用
应用场景：
...
How do you use bcrypt for hashing passwords in PHP?
... algorithm. You cannot retrieve the plain text password without already knowing the salt, rounds and key (password). [Source]
How to use bcrypt:
Using PHP >= 5.5-DEV
Password hashing functions have now been built directly into PHP >= 5.5. You may now use password_hash() to create a bcrypt h...
What is the performance of Objects/Arrays in JavaScript? (specifically for Google V8)
...n investigation to the question of how implementations behave regarding growing arrays: If they implement them the "usual" way, one would see many quick pushes with rare, interspersed slow pushes at which point the implementation copies the internal representation of the array from one buffer to a l...
Mutex example / tutorial? [closed]
...le concurrently, we have potential for a race condition. Consider the following code
//somewhere long ago, we have i declared as int
void my_concurrently_called_function()
{
i++;
}
The internals of this function look so simple. It's only one statement. However, a typical pseudo-assembly languag...