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Is there a way to make GHC provide the type class constraints of typed holes?
...ing, this isn't immediately obvious in GHCi. With your example,
> show _
<interactive>:7:6: error:
• Found hole: _h :: ()
Or perhaps ‘_h’ is mis-spelled, or not in scope
• In the first argument of ‘show’, namely ‘_h’
In the expression: show _h
I...
What is the most pythonic way to check if an object is a number?
...: 0 + x
except TypeError: canadd=False
else: canadd=True
The presence of __add__ per se tells you nothing useful, since e.g all sequences have it for the purpose of concatenation with other sequences. This check is equivalent to the definition "a number is something such that a sequence of such t...
What is the documents directory (NSDocumentDirectory)?
...lowing tech note: https://developer.apple.com/library/ios/technotes/tn2406/_index.html
The Apple sanctioned way (from the link above) is as follows:
// Returns the URL to the application's Documents directory.
- (NSURL *)applicationDocumentsDirectory
{
return [[[NSFileManager defaultManager] U...
Objective-C ARC: strong vs retain and weak vs assign
...on error to use assign for an object. You have to use either weak or unsafe_unretained (which is unsafe, obviously) if you don't want to retain the property.
– cobbal
Jan 19 '12 at 15:07
...
Capture keyboardinterrupt in Python without try-except
...g.Event:
import signal
import sys
import time
import threading
def signal_handler(signal, frame):
print('You pressed Ctrl+C!')
sys.exit(0)
signal.signal(signal.SIGINT, signal_handler)
print('Press Ctrl+C')
forever = threading.Event()
forever.wait()
...
How do I access the request object or any other variable in a form's clean() method?
... no reason to do it this way.
A much better way is to override the form's __init__ method to take an extra keyword argument, request. This stores the request in the form, where it's required, and from where you can access it in your clean method.
class MyForm(forms.Form):
def __init__(self, *...
Why can't C compilers rearrange struct members to eliminate alignment padding? [duplicate]
...ng the ZIP implementation would like to access the data directly):
struct __attribute__((__packed__)) LocalFileHeader {
uint32_t signature;
uint16_t minVersion, flag, method, modTime, modDate;
uint32_t crc32, compressedSize, uncompressedSize;
uint16_t nameLength, extraLength;
};
T...
Possibility of duplicate Mongo ObjectId's being generated in two different collections?
...hey are generated on different machines.
Now if you were referring to the _id field in general, we do not require uniqueness across collections so it is safe to reuse the old _id. As a concrete example, if you have two collections, colors and fruits, both could simultaneously have an object like {_...
Inserting multiple rows in mysql
...sed within parentheses and separated by commas.
Example:
INSERT INTO tbl_name
(a,b,c)
VALUES
(1,2,3),
(4,5,6),
(7,8,9);
Source
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What is “android.R.layout.simple_list_item_1”?
...ayout.html
(Updated link thanks @Estel: https://github.com/android/platform_frameworks_base/tree/master/core/res/res/layout )
You can actually view the code for the layouts.
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