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How do you know when to use fold-left and when to use fold-right?
...re, you use a left fold. Example (haskell-style pseudocode)
foldl (-) [1, 2, 3] == (1 - 2) - 3 == 1 - 2 - 3 // - is left-associative
If your operator is right-associative (right fold), the parentheses would be set like this:
A x (B x (C x D))
Example: Cons-Operator
foldr (:) [] [1, 2, 3] == 1...
what is the preferred way to mutate a React state?
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edited May 31 '14 at 21:45
Brigand
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an...
What do (lambda) function closures capture?
...e a new scope each time you create the lambda:
>>> adders = [0,1,2,3]
>>> for i in [0,1,2,3]:
... adders[i] = (lambda b: lambda a: b + a)(i)
...
>>> adders[1](3)
4
>>> adders[2](3)
5
The scope here is created using a new function (a lambda, for brevity...
How to not run an example using roxygen2?
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answered Aug 20 '12 at 13:03
GSeeGSee
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Asterisk in function call
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182
* is the "splat" operator: It takes a list as input, and expands it into actual positional argum...
Convert list of dictionaries to a pandas DataFrame
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edited Jul 22 at 17:24
cs95
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How to see which flags -march=native will activate?
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152
You can use the -Q --help=target options:
gcc -march=native -Q --help=target ...
The -v optio...
How to manually deprecate members
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273
You can use the Available tag, for example :
@available(*, deprecated)
func myFunc() {
/...
“x not in y” or “not x in y”
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112
They always give the same result.
In fact, not 'ham' in 'spam and eggs' appears to be special c...
What is the maximum float in Python?
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279
For float have a look at sys.float_info:
>>> import sys
>>> sys.float_info
...