Protocols may define associated type requirements using the associatedtype keyword:
protocol Container {
associatedtype Element
var count: Int { get }
subscript(index: Int) -> Element { get set }
}
Protocols with associated type requirements can only be used as generic constraints:...
The Problem
The abstract equality and inequality operators (== and !=) convert their operands if the operand types do not match. This type coercion is a common source of confusion about the results of these operators, in particular, these operators aren't always transitive as one would expect.
&...
You can specify different application IDs or package names for each buildType or productFlavor using the applicationIdSuffix configuration attribute:
Example of suffixing the applicationId for each buildType:
defaultConfig {
applicationId "com.package.android"
minSdkVersion 17
...
When writing a class with generics in java, it is possible to ensure that the type parameter is an enum. Since all enums extend the Enum class, the following syntax may be used.
public class Holder<T extends Enum<T>> {
public final T value;
public Holder(T init) {
t...
function listener(e:Event):void {
var m:MovieClip=e.target as MovieClip;
m.x++;
}
If such a listener is attached to an object that's not a MovieClip descendant (for example, a Sprite), the typecast will fail, and any subsequent operations with its result will throw the 1009 error.
Haskell supports a notion of class extension. For example, the class Ord inherits all of the operations in Eq, but in addition has a compare function that returns an Ordering between values. Ord may also contain the common order comparison operators, as well as a min method and a max method.
The =&...
CMake knows several build types, which usually influence default compiler and linker parameters (such as debugging information being created) or alternative code paths.
By default, CMake is able to handle the following build types:
Debug: Usually a classic debug build including debugging informa...
Fortran 2003 introduced support for object oriented programming. This feature allows to take advantage of modern programming techniques. Derived types are defined with the following form:
TYPE [[, attr-list] :: ] name [(name-list)]
[def-stmts]
[PRIVATE statement or SEQUENCE statement]. . .
...
An extensible derived type may be abstract
type, abstract :: base_type
end type
Such a derived type may never be instantiated, such as by
type(base_type) t1
allocate(type(base_type) :: t2)
but a polymorphic object may have this as its declared type
class(base_type), allocatable :: t1
o...
To change the appearance of the keyboard, the following types can be set individually on every UITextFields property: keyboardType
typedef NS_ENUM(NSInteger, UIKeyboardType) {
UIKeyboardTypeDefault, // Default type for the current input method.
UIKeyboardTypeASCIICapable, ...
Use associated type when there is a one-to-one relationship between the type implementing the trait and the associated type.
It is sometimes also known as the output type, since this is an item given to a type when we apply a trait to it.
Creation
trait GetItems {
type First;
// ^~~~ d...
A closure can be defined with a typealias. This provides a convenient type placeholder if the same closure signature is used in multiple places. For example, common network request callbacks or user interface event handlers make great candidates for being "named" with a type alias.
public...
astype() method changes the dtype of a Series and returns a new Series.
In [1]: df = pd.DataFrame({'A': [1, 2, 3], 'B': [1.0, 2.0, 3.0],
'C': ['1.1.2010', '2.1.2011', '3.1.2011'],
'D': ['1 days', '2 days', '3 days'],
...
select_dtypes method can be used to select columns based on dtype.
In [1]: df = pd.DataFrame({'A': [1, 2, 3], 'B': [1.0, 2.0, 3.0], 'C': ['a', 'b', 'c'],
'D': [True, False, True]})
In [2]: df
Out[2]:
A B C D
0 1 1.0 a True
1 2 2.0 b False
2...
get_dtype_counts method can be used to see a breakdown of dtypes.
In [1]: df = pd.DataFrame({'A': [1, 2, 3], 'B': [1.0, 2.0, 3.0], 'C': ['a', 'b', 'c'],
'D': [True, False, True]})
In [2]: df.get_dtype_counts()
Out[2]:
bool 1
float64 1
int64 1
obje...
Modules can be used to add new functions to existing Modules and Types.
namespace FSharp.Collections
module List =
let pair item1 item2 = [ item1; item2 ]
The new function can then be called as if it was an original member of List.
open FSharp.Collections
module Testing =
le...
A JID consists of three parts: localpart@domainpart/resourcepart.
Full JIDs (always have a resource part)
[email protected]/orchard
example.org/da863ab
Bare JIDs (always without resource part)
[email protected]
example.org
