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Error handling in C code
... your library as painless as possible think about these additions:
store all possible error-states in one typedef'ed enum and use it in your lib. Don't just return ints or even worse, mix ints or different enumerations with return-codes.
provide a function that converts errors into something huma...
What does = +_ mean in JavaScript
I was wondering what the = +_ operator means in JavaScript. It looks like it does assignments.
12 Answers
...
What does -D_XOPEN_SOURCE do/mean?
...ch one you need (if any) by looking at the man page for each function you call.
For example, man strdup says:
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
strdup(): _SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 500
strndup(), strdupa(), strndupa():...
Why should eval be avoided in Bash, and what should I use instead?
...rintln. We could, of course, just redirect the output of println on each call, but for the sake of example, we're not going to do that. We'll need to use eval, since variables can't be used to redirect output.
function println
{
eval printf "$2\n" "${@:3}" $1
}
function error
{
println '...
How do I output coloured text to a Linux terminal?
...
You need to output ANSI colour codes. Note that not all terminals support this; if colour sequences are not supported, garbage will show up.
Example:
cout << "\033[1;31mbold red text\033[0m\n";
Here, \033 is the ESC character, ASCII 27. It is followed by [, then zero o...
Use ASP.NET MVC validation with jquery ajax?
...est;
}
}
}
What this does is return a JSON object specifying all of your model errors.
Example response would be
[{
"key":"Name",
"errors":["The Name field is required."]
},
{
"key":"Description",
"errors":["The Description field is required."]
}]
This would be retu...
How do you remove duplicates from a list whilst preserving order?
...n seen or seen_add(x))]
Why assign seen.add to seen_add instead of just calling seen.add? Python is a dynamic language, and resolving seen.add each iteration is more costly than resolving a local variable. seen.add could have changed between iterations, and the runtime isn't smart enough to rule t...
Compare two DataFrames and output their differences side-by-side
...original question
The first step is to concatenate the DataFrames horizontally with the concat function and distinguish each frame with the keys parameter:
df_all = pd.concat([df.set_index('id'), df2.set_index('id')],
axis='columns', keys=['First', 'Second'])
df_all
It's pr...
Plotting time in Python with Matplotlib
...erstand why this is the 5th question I've encountered where no one has actually TRIED using a scatter plot - it doesn't work. Type Error - invalid type promotion.
– dwanderson
Oct 5 '16 at 16:21
...
Can someone explain the right way to use SBT?
...tarted, and why?
I think the sane point is to build immunity to sbt gradually.
Make sure you understand:
scopes format {<build-uri>}<project-id>/config:key(for task-key)
the 3 flavors of settings (SettingKey, TaskKey, InputKey) - read the section called "Task Keys" in http://www.sc...