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What do the makefile symbols $@ and $< mean?
...e name of the target being generated, and $< the first prerequisite (usually a source file). You can find a list of all these special variables in the GNU Make manual.
For example, consider the following declaration:
all: library.cpp main.cpp
In this case:
$@ evaluates to all
$< evaluates to...
Copy a stream to avoid “stream has already been operated upon or closed”
...ata, then by definition you either have to generate it twice (deterministically) or store it. If it already happens to be in a collection, great; then iterating it twice is cheap.
We did experiment in the design with "forked streams". What we found was that supporting this had real costs; it bu...
Max length for client ip address [duplicate]
...esses are 128 bits (as opposed to 32 bits of IPv4 addresses). They are usually written as 8 groups of 4 hex digits separated by colons: 2001:0db8:85a3:0000:0000:8a2e:0370:7334. 39 characters is appropriate to store IPv6 addresses in this format.
Edit: However, there is a caveat, see @Deepak's ans...
shortcut for creating a Map from a List in groovy?
...
Check out "inject". Real functional programming wonks call it "fold".
columns.inject([:]) { memo, entry ->
memo[entry.name] = entry.val
return memo
}
And, while you're at it, you probably want to define methods as Categories instead of right on the metaClass. That ...
Is there a rule-of-thumb for how to divide a dataset into training and validation sets?
...ry variance in your estimates. If you have 100,000 instances, it doesn't really matter whether you choose an 80:20 split or a 90:10 split (indeed you may choose to use less training data if your method is particularly computationally intensive).
Assuming you have enough data to do proper held-out t...
How can I force gradle to redownload dependencies?
...
Generally, you can refresh dependencies in your cache with the command line option --refresh-dependencies. You can also delete the cached files under ~/.gradle/caches. With the next build Gradle would attempt to download them agai...
How to stop an app on Heroku?
... your app you can scale the web dynos down to zero which effectively takes all your app http-processes offline.
$ heroku ps:scale web=0
Scaling web processes... done, now running 0
share
|
improve...
How can I use optional parameters in a T-SQL stored procedure?
...dure to do a search through a table. I have many different search fields, all of which are optional. Is there a way to create a stored procedure that will handle this? Let's say I have a table with four fields: ID, FirstName, LastName and Title. I could do something like this:
...
Using sphinx with Markdown instead of RST
...on to choose the parser.) The beauty of this would be instant support for all docutils output formats (but you might not care about that, as similar markdown tools already exist for most). Ways to approach that without developing a parser from scratch:
You could cheat and write a "parser" that us...
What's the rationale for null terminated strings?
... by a
special character, which B spelled
*e. This change was made partially
to avoid the limitation on the length
of a string caused by holding the
count in an 8- or 9-bit slot, and
partly because maintaining the count
seemed, in our experience, less
convenient than using a terminato...