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What does the exclamation mark mean in a Haskell declaration?
...to look inside it, probably through a pattern match:
case f of
Foo 0 _ _ _ -> "first arg is zero"
_ -> "first arge is something else"
This is going to execute enough code to do what it needs, and no more. So it will create a Foo with four parameters (because you can't lo...
How to create a GUID/UUID using iOS
...tring = CFUUIDCreateString(NULL, theUUID);
CFRelease(theUUID);
return (__bridge NSString *)string;
}
EDIT: Jan, 29 2014:
If you're targeting iOS 6 or later, you can now use the much simpler method:
NSString *UUID = [[NSUUID UUID] UUIDString];
...
Spring Data JPA find by embedded object property
...Long twoId); and results in a query of the form: select ...... from one one_ left outer join two two_ on one_.two_id = two_.id where one_id = ? and two_.id = ?
– TroJaN
May 4 at 17:17
...
Split views.py in several files
...everything is a Python module (*.py). You can create a view folder with an __init__.py inside and you still will be able to import your views, because this also implements a Python module. But an example would be better.
Your original views.py might look like this :
def view1(arg):
pass
def v...
CSS styling in Django forms
...aken from my answer to:
How to markup form fields with <div class='field_type'> in Django
class MyForm(forms.Form):
myfield = forms.CharField(widget=forms.TextInput(attrs={'class' : 'myfieldclass'}))
or
class MyForm(forms.ModelForm):
class Meta:
model = MyModel
def __i...
Unique constraint on multiple columns
...ied from technet's documentation, is in the form of:
CONSTRAINT constraint_name UNIQUE [ CLUSTERED | NONCLUSTERED ]
(
column [ ASC | DESC ] [ ,...n ]
)
Therefore, the resuting table definition would be:
CREATE TABLE [dbo].[user](
[userID] [int] IDENTITY(1,1) NOT NULL,
[fcode] [int] ...
class method generates “TypeError: … got multiple values for keyword argument …”
...de:
myfoo.foodo("something")
print
print myfoo
You'll output like:
<__main__.foo object at 0x321c290>
a thong is something
<__main__.foo object at 0x321c290>
You can see that 'thing' has been assigned a reference to the instance 'myfoo' of the class 'foo'. This section of the docs...
Where to find Java JDK Source Code? [closed]
...d page, what to I have do download? The big file jdk-6u21-ea-src-b04-jrl-05_may_2010.jar, 136.48 MB? I already downloaded that one. But doesn't contain the source code.
– Martijn Courteaux
May 24 '10 at 12:06
...
How to perform Callbacks in Objective-C
...newer) option is to use blocks:
@interface MyClass: NSObject
{
void (^_completionHandler)(int someParameter);
}
- (void) doSomethingWithCompletionHandler:(void(^)(int))handler;
@end
@implementation MyClass
- (void) doSomethingWithCompletionHandler:(void(^)(int))handler
{
// NOTE: copyin...
Read only the first line of a file?
...od (Python 2 docs, Python 3 docs):
with open('myfile.txt') as f:
first_line = f.readline()
Some notes:
As noted in the docs, unless it is the only line in the file, the string returned from f.readline() will contain a trailing newline. You may wish to use f.readline().strip() instead to rem...