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What does the `forall` keyword in Haskell/GHC do?
...here
val :: b
val = maybe onNothin onJust mval
This code doesn't compile (syntax error) in plain Haskell 98. It requires an extension to support the forall keyword.
Basically, there are 3 different common uses for the forall keyword (or at least so it seems), and each has its own ...
Array versus List: When to use which?
...f use of arrays in my protobuf-net project; entirely for performance:
it does a lot of bit-shifting, so a byte[] is pretty much essential for encoding;
I use a local rolling byte[] buffer which I fill before sending down to the underlying stream (and v.v.); quicker than BufferedStream etc;
it inte...
How do I implement basic “Long Polling”?
...
It's simpler than I initially thought.. Basically you have a page that does nothing, until the data you want to send is available (say, a new message arrives).
Here is a really basic example, which sends a simple string after 2-10 seconds. 1 in 3 chance of returning an error 404 (to show error ...
How to get a random value from dictionary in python
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Is this efficient? Does this scale if dict gets really large?
– Spectral
Jul 25 '15 at 19:11
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Why java.lang.Object is not abstract? [duplicate]
... of Object any time we wanted to synchronise on a certain object, but this doesn't stand up - an empty subclass could have been provided in the SDK (java.lang.Lock or whatever), which could be constructed any time we wanted to synchronise. Doing this would have the added benefit of creating a strong...
Why does document.querySelectorAll return a StaticNodeList rather than a real Array?
...erator isn't very DOM-like it's
that it isn't very JavaScript-like. It
doesn't take advantage of the features
present in the JavaScript language and
use them to the best of its ability...
I do somewhat empathize. If the DOM was written specifically with JavaScript features in mind it would...
Is there a way to list pip dependencies/requirements?
...accepted answer is no longer relevant for more current versions of pip and does not give an immediate answer without perusing multiple comments so I am providing an updated answer.
This was tested with pip versions 8.1.2, 9.0.1, 10.0.1, and 18.1.
To get the output without cluttering your current d...
Regex Pattern to Match, Excluding when… / Except between
...ecipe?
Key Fact
The method returns the match in Group 1 capture. It does not care at
all about the overall match.
In fact, the trick is to match the various contexts we don't want (chaining these contexts using the | OR / alternation) so as to "neutralize them". After matching all the unw...
Is there a difference between `continue` and `pass` in a for loop in python?
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Yes, they do completely different things. pass simply does nothing, while continue goes on with the next loop iteration. In your example, the difference would become apparent if you added another statement after the if: After executing pass, this further statement would be exe...
How to merge every two lines into one from the command line?
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Does not work with colored output. I tried everything on this Q&A and nothing worked when the output is ansi colored. Tested on Ubuntu 13.04
– Leo Gallucci
Dec 9 '13 at 22:54
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