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What are bitwise shift (bit-shift) operators and how do they work?
... powerful: one operand of any instruction can be left or right shifted for free. So scaling by a compile-time-constant that's known to be a power-of-2 can be even more efficient than a multiply.
OK, back in the modern days... something more useful now would be to use bitshifting to store two 8-b...
How do I get current date/time on the Windows command line in a suitable format for usage in a file/
...%m-%%d.%%H%%M%%S"') do ren file.txt file.%%i.txt
date.exe is part of the free GNU tools which need no installation.
NOTE: Copying date.exe into any directory which is in the search path may cause other scripts to fail that use the Windows built-in date command.
...
java.sql.SQLException: - ORA-01000: maximum open cursors exceeded
...et nor the connection object.
But still we have to close the resultset to free some oracle memory. Still if you don't close the resultset that won't be counted for CURSORS.
Closing Statement object will automatically close resultset object too.
Cursor will be created for all the SELECT/INSERT/UPD...
What are the best practices for catching and re-throwing exceptions?
...omething to the caught exception, may it be some context, values, logging, freeing resources, whatever.
A way to add some information is to extend the Exception class, to have exceptions like NullParameterException, DatabaseException, etc. More over, this allow the developper to only catch some exc...
Benchmarking (python vs. c++ using BLAS) and (numpy)
...y would recommend to use GotoBlas2 because it's easier to install and it's free.
If you want to code in C++/C also check out Eigen3 which is supposed to outperform MKL/GotoBlas2 in some cases and is also pretty easy to use.
...
Questions every good .NET developer should be able to answer? [closed]
...t the intimate details of the garbage collector and how it decides when to free memory. Sure, you could ask candidates "how does a garbage collector work", but asking about weak references gets a much better, more thoughtful reply.
.NET is a fairly abstract language, but star developers almost alw...
How to import multiple .csv files at once?
...ead(.))
The stringsAsFactors = FALSE argument keeps the dataframe factor free, (and as marbel points out, is the default setting for fread)
If the typecasting is being cheeky, you can force all the columns to be as characters with the col_types argument.
tbl <-
list.files(pattern = "*.csv...
Why is “while ( !feof (file) )” always wrong?
...amp;bufsiz, fp)) != -1)
{
/* Use nbytes of data in buffer */
}
free(buffer);
The result we must use is nbytes, the number of bytes up to and including the newline (or EOF if the file did not end with a newline).
Note that the function explicitly returns -1 (and not EOF!) when an error o...
Why isn't String.Empty a constant?
...nt, because the containing Y is a class" was just a little bit too context-free ;) – Leonidas Feb 3 '09 at 17:01
string.Empty is static property that returns an instance of the String class, namely the empty string, not the string class itself. – tvanfosson Feb 3 '09 at 17:01
Empty is ...
What is the difference between LR, SLR, and LALR parsers?
... said all this, it is worth knowing that GLR parsers can parse any context free language, using more complicated machinery but exactly the same tables (including the smaller version used by LALR). This means that GLR is strictly more powerful than LR, LALR and SLR; pretty much if you can write a sta...