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Java's Interface and Haskell's type class: differences and similarities?
...d say that an interface is kind of like a type class SomeInterface t where all of the values have the type t -> whatever (where whatever does not contain t). This is because with the kind of inheritance relationship in Java and similar languages, the method called depends on the type of object th...
How can I efficiently select a Standard Library container in C++11?
...ited May 16 '16 at 7:29
user2508324
answered May 22 '12 at 11:26
Matthieu M.Matthieu M.
...
Entity Framework 5 Updating a Record
...y Framework 5 in an ASP.NET MVC3 environment, but so far none of them tick all of the boxes I need. I'll explain why.
7 Ans...
Django select only rows with duplicate field values
... syntax is also how Django interprets you wanting to do a join. So, essentially when you try to filter on that, Django thinks you're trying to do a join with count which obviously doesn't exist. The fix is to specify a name for your annotation result, i.e. annotate(mycount=Count('id')) and then filt...
How can I view the source code for a function?
...a.frame"
x="Raster", y="Extent"
x="Raster", y="matrix"
x="Raster", y="SpatialLines"
x="Raster", y="SpatialPoints"
x="Raster", y="SpatialPolygons"
x="Raster", y="vector"
To see the source code for one of these methods the entire signature must be supplied, e.g.
getMethod("extract" , signature = c(...
What is the difference between CMD and ENTRYPOINT in a Dockerfile?
...ypoint. i.e., the actual thing that gets executed is /bin/sh -c bash. This allowed Docker to implement RUN quickly by relying on the shell's parser.
Later on, people asked to be able to customize this, so ENTRYPOINT and --entrypoint were introduced.
Everything after ubuntu in the example above is ...
Easiest way to check for an index or a key in an array?
... associative array)
[ ${array[key]+abc} ] && echo "exists"
Basically what ${array[key]+abc} does is
if array[key] is set, return abc
if array[key] is not set, return nothing
References:
See Parameter Expansion in Bash manual and the little note
if the colon is omitted, the ope...
Xml serialization - Hide null values
When using a standard .NET Xml Serializer, is there any way I can hide all null values? The below is an example of the output of my class. I don't want to output the nullable integers if they are set to null.
...
How to get everything after a certain character?
...te fast.
$s = '233718_This_is_a_string';
$firstPart = strtok( $s, '_' );
$allTheRest = strtok( '' );
Empty string like this will force the rest of the string to be returned.
NB if there was nothing at all after the '_' you would get a FALSE value for $allTheRest which, as stated in the document...
When should I use Inline vs. External Javascript?
...
At the time this answer was originally posted (2008), the rule was simple: All script should be external. Both for maintenance and performance.
(Why performance? Because if the code is separate, it can easier be cached by browsers.)
JavaScript doesn't belon...