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What optimizations can GHC be expected to perform reliably?
...Right x
As an extended example, take this definition of last:
last [] = error "last: empty list"
last (x:[]) = x
last (x:x2:xs) = last (x2:xs)
We first transform it to
last_nil = error "last: empty list"
last_cons x [] = x
last_cons x (x2:xs) = last (x2:xs)
{-# INLINE last #-}
last [] = last_...
What is 'Pattern Matching' in functional languages?
...
head :: List a -> a
-- An empty list has no first item, so we raise an error.
head Nil = error "empty list"
-- If we are given a `Cons`, we only want the first part; that's the list's head.
head (Cons h _) = h
Since List a values can be of two different kinds, we need to handle each one...
Save Screen (program) output to a file
..., a screen run overnight with a config file created and deleted on the fly errored out on a screen -r with "Unable to open "/tmp/log.conf". Also, the screen went from [detached] state to non-existent. What could have been the problem?
– Ram RS
Oct 13 '16 at 14:...
How to pick just one item from a generator?
...
answered Feb 22 at 10:05
Dave RoveDave Rove
53044 silver badges99 bronze badges
...
What's the fastest way to loop through an array in JavaScript?
...e better performance, writing code that is less legible and more prone to errors than a simple straightforward for loop. Therefore, I recommend:
If your app iterates over a lot of items or your loop code is inside a function that is used often, a straightforward for loop is the answer:
for (var ...
Eclipse - Unable to install breakpoint due to missing line number attributes
I am getting this strange error in Eclipse while trying to set a breakpoint.
41 Answers
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Swift Beta performance: sorting arrays
...level [-O].
Here is an in-place quicksort in Swift Beta:
func quicksort_swift(inout a:CInt[], start:Int, end:Int) {
if (end - start < 2){
return
}
var p = a[start + (end - start)/2]
var l = start
var r = end - 1
while (l <= r){
if (a[l] < p){
...
How do I download a tarball from GitHub using cURL?
...temporary problem right now, but github is returning a 500 internal server error for this at the moment.
– B T
Oct 29 '13 at 21:15
15
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How to sort two lists (which reference each other) in the exact same way
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I get an error running your example: TypeError: only integer arrays with one element can be converted to an index (Python 2.7.6, numpy 1.8.2). To fix it, list1 and list2 must be declared as numpy arrays.
– BenB
...
Set UIButton title UILabel font size programmatically
... 11:36:34.503 MyApp[3579:707] Family name: Gurmukhi MN
2012-04-02 11:36:34.507 MyApp[3579:707] Font name: GurmukhiMN
2012-04-02 11:36:34.511 MyApp[3579:707] Font name: GurmukhiMN-Bold
2012-04-02 11:36:34.514 MyApp[3579:707] Family name: Malayalam Sangam MN
2012-04-02 11:36:34.518 MyApp[3579:...