cycle is an infinite iterator.
>>> import itertools as it
>>> it.cycle('ABCD')
A B C D A B C D A B C D ...
Therefore, take care to give boundaries when using this to avoid an infinite loop. Example:
>>> # Iterate over each element in cycle for a fixed range
>&g...
When to use abstract classes: To implement the same or different behaviour among multiple related objects
When to use interfaces: to implement a contract by multiple unrelated objects
Abstract classes create "is a" relations while interfaces provide "has a" capability.
This c...
sudo apt-add-repository ppa:brightbox/ruby-ng
Hit Enter to confirm
sudo apt-get update
Then you can install your ruby version of choice (the ppa supports ruby2.0 ruby2.1 ruby2.2 ruby2.3 and legacy versions ruby1.8 ruby1.9.1) Don't forget to include the respective -dev package for your version. Ot...
Create Or Replace Function Generateguid
Return Char Is
V_Guid Char(40);
Begin
Select Substr(Sys_Guid(),1,8)||'-'||Substr(Sys_Guid(),9,4)||'-'
||Substr(Sys_Guid(),13,4)||'-'||Substr(Sys_Guid(),17,4)||'-'
||Substr(Sys_Guid(),21) Into V_Guid...
Disclaimer: In no way does this example advocate the use of singletons. Singletons are to be used with a lot of care.
In PHP there is quite a standard way of implementing a singleton:
public class Singleton {
private $instance;
private function __construct() { };
public function...
With implicit keys:
key: value
another key:
- some
- more
- values
[1, 2, 3]: last value, which has a flow style key
With implicit and explicit keys:
? key
: value
another key:
- some
- more
- values
? [1, 2, 3]
: last value, which has a flow style key
key, another ...
To see all the facts involving the le relation from the prelude:
Coq < Search le.
le_n: forall n : nat, n <= n
le_S: forall n m : nat, n <= m -> n <= S m
...
max_l: forall n m : nat, m <= n -> Nat.max n m = n
max_r: forall n m : nat, n <= m -> Nat.max n m = m
...
...
Search for all facts involving a pattern in an hypothesis or conclusion:
Coq < Search (_ + O).
plus_n_O: forall n : nat, n = n + 0
The _ character serves as a wildcard, it can be used multiple times:
Coq < Search (S _ <= _).
le_S_n: forall n m : nat, S n <= S m -> n <= m
le...
Session Types are a way to tell the compiler about the protocol you want to use to communicate between threads - not protocol as in HTTP or FTP, but the pattern of information flow between threads. This is useful since the compiler will now stop you from accidentally breaking your protocol and causi...
Let's say your launch activity is called MainActivity, in your app com.example.myapp.
In the manifest:
<activity
android:name=".MainActivity"
>
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
...
Bridge pattern decouples abstraction from implementation so that both can vary independently. It has been achieved with composition rather than inheritance.
Bridge UML diagram from wikipedia:
You have four components in this pattern.
Abstraction: It defines an interface
RefinedAbstraction: It ...
The dimension attribute on an object specifies that that object is an array. There are, in Fortran 2008, five array natures:1
explicit shape
assumed shape
assumed size
deferred shape
implied shape
Take the three rank-1 arrays2
integer a, b, c
dimension(5) a ! Explicit shape (default ...
If the value of the href-attribute begins with tel:, your device will dial the number when you click it. This works on mobile devices or on computers/tablets running software – like Skype or FaceTime – that can make phone calls.
<a href="tel:11234567890">Call us</a>
Most de...
SUB function allows to substitute text inside awk
sub(regexp, replacement, target)
where regexp could be a full regular expression
$ cat file
AAAAA
BBBB
CCCC
DDDD
EEEE
FFFF
GGGG
$ awk '{sub("AAA","XXX", $0); print}' file
XXXAA
BBBB
CCCC
DDDD
EEEE
FFFF
GGGG
...
A Range cannot be created or populated the same way a string would:
Sub RangeTest()
Dim s As String
Dim r As Range 'Specific Type of Object, with members like Address, WrapText, AutoFill, etc.
' This is how we fill a String:
s = "Hello World!"
' But we can...
