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Understanding typedefs for function pointers in C
...d returns a SignalHandler.
It takes a bit of getting used to, though. The one thing you can't do, though is write a signal handler function using the SignalHandler typedef in the function definition.
I'm still of the old-school that prefers to invoke a function pointer as:
(*functionpointer)(arg1, ...
Python memoising/deferred lookup property decorator
Recently I've gone through an existing code base containing many classes where instance attributes reflect values stored in a database. I've refactored a lot of these attributes to have their database lookups be deferred, ie. not be initialised in the constructor but only upon first read. These attr...
Method chaining - why is it a good practice, or not?
... writing code easier (especially with IntelliSense). Mind you that this is one isolated case though, and is not a general practice in my code.
The point is - in 99% cases you can probably do just as well or even better without method chaining. But there is the 1% where this is the best approach.
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How to change the foreign key referential action? (behavior)
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Old question but adding answer so that one can get help
Its two step process:
Suppose, a table1 has a foreign key with column name fk_table2_id, with constraint name fk_name and table2 is referred table with key t2 (something like below in my diagram).
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What is “assert” in JavaScript?
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There is no assert in JavaScript (yet; there's talk of adding one, but it's at an early stage). Perhaps you're using some library that provides one. The usual meaning is to throw an error if the expression passed into the function is false; this is part of the general concept of asserti...
How to normalize a NumPy array to within a certain range?
...ized within a range before it can be written back to a file. This can be done like so:
7 Answers
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Factors in R: more than an annoyance?
One of the basic data types in R is factors. In my experience factors are basically a pain and I never use them. I always convert to characters. I feel oddly like I'm missing something.
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How efficient can Meteor be while sharing a huge collection among many clients?
...allers register
callbacks for the same live query, the driver only watches one copy of
the query, calling each registered callback with the same result.
Each time the server updates a collection, the driver recalculates each
live query on that collection (Future versions of Meteor will expose a
sca...
What is the difference between a thread and a fiber?
.../etc.). This means that for threads, data integrity is a big issue because one thread may be stopped in the middle of updating a chunk of data, leaving the integrity of the data in a bad or incomplete state. This also means that the operating system can take advantage of multiple CPUs and CPU cores ...
Equivalent of “throw” in R
How does one "throw" an error in R? I have a function that takes a data frame and some column names and does stuff with them. If the columns don't exist, I want the function to stop and to stop all functions depending on it.
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