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Is there a way to make GHC provide the type class constraints of typed holes?
...
This is now fixed in GHC 8.0 thanks to @DominiqueDevriese's GHC ticket.
Due to extended type defaulting, this isn't immediately obvious in GHCi. With your example,
> show _
<interactive>:7:6: error:
• Found hole: ...
How to get the name of enumeration value in Swift?
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As of Xcode 7 beta 5 (Swift version 2) you can now print type names and enum cases by default using print(_:), or convert to String using String's init(_:) initializer or string interpolation syntax. So for your example:
enum City: Int {
case Melbourne = 1, Chelyabin...
“Private” (implementation) class in Python
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I did not know the underscore rule extended to classes. I do not want to clutter my namespace when importing, so this behavior is what I was looking for. Thanks!
– oparisy
Feb 15 '09 at 19:52
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How to import multiple .csv files at once?
...mp<-list.files(pattern="*.csv") ddives <- lapply(temp, read.csv) So now each file is called ddives[n] but how would I go about writing a loop to make them all data frames rather than single objects? I can achieve this individually using the data.frame operator but am unsure as to how to loop ...
Are JavaScript strings immutable? Do I need a “string builder” in JavaScript?
...135 | 1135 | 1200 | 4357 | 1137 | 1188 | 4294 |
Findings
Nowadays, all evergreen browsers handle string concatenation well. Array.join only helps IE 11
Overall, Opera is fastest, 4 times as fast as Array.join
Firefox is second and Array.join is only slightly slower in FF but consi...
How many GCC optimization levels are there?
...00' '-v' '-mtune=generic' '-march=x86-64'
/usr/local/libexec/gcc/x86_64-unknown-linux-gnu/5.1.0/cc1 [[noise]] hello_world.c -O100 -o /tmp/ccetECB5.
so -O was forwarded to both cc1 and collect2.
O in common.opt
common.opt is a GCC specific CLI option description format described in the internals doc...
Does python have an equivalent to Java Class.forName()?
...a.
I recommend reading this tutorial
There's no direct function (that I know of) which takes a fully qualified class name and returns the class, however you have all the pieces needed to build that, and you can connect them together.
One bit of advice though: don't try to program in Java style wh...
C default arguments
... double x_out = in.x ? in.x : 3.14;
return f_base(i_out, x_out);
}
Now add a macro, using C's variadic macros. This way users don't have to know they're
actually populating a f_args struct and think they're doing the usual:
#define f(...) var_f((f_args){__VA_ARGS__});
OK, now all of the f...
javac not working in windows command prompt
... of checking, execute:
echo %path%
from your command prompt and let us know what it is.
Otherwise, make sure there is a javac in that directory by trying:
"c:\program files\java\jdk1.6.0_16\bin\javac.exe"
from the command prompt. You can also tell which executable (if any) is being used with ...
Plotting time in Python with Matplotlib
...ve returns a list with one object of type: matplotlib.lines.Line2D object. Now how do I use this to show the graph?
– Arindam Roychowdhury
Jul 20 '17 at 6:59
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