echo() ->
    receive
        {From, Msg} -> From ! {Msg}, echo();
        %^pattern^    %^response^   %^keep loop
        stop -> true
        %^pattern^  ^a return value and stop receiving
    end.

sudo brew install redis-server

redis-server

redis-cli ping

ECHO 'hello word

QUIT

SET foo 100

GET foo // 100

SET bar 'hello world'

GET bar // hello world

INCR foo // 101

DECR foo // 100

EXISTS foo // 1

EXISTS foo1 // 0

DEL bar

EXISTS bar // 0

GET bar //(nir)

FLUSHALL // all empty

SET server:name someserver

GET server:name // "someserver"

SET server:port 8000

GET server:port

SET greeting "Hello world"

GET greeting

EXPIRE greeting 50  // set expirations to 50 second

TTL greeting

SETEX greeting 30 "hello world" // set value and expiration

PERSIST greeting // key will not expire

TTL greeting // -1

MSET key1 "hello" key2 "world"

APPEND key1 " world"

RENAME key1 greeting

LPUSH people "Brad" // 1

LPUSH people "Jen" // 2

LPUSH people "Tom" // 3

LRANGE people 0 -1 // return all // Tom Jen Brad

LRANGE people 1 2 // Jen Brad

RPUSH people "Harry"

LRANGE people 0 -1 // Tom Jen Brad Harry

LLEN people // 4

RPOP people // Harry

LPOP people

LINSERT people BEFORE "Brad" "TOM"

LRANGE people 0 -1 // Jen Tom Brad

SADD cars "Ford"

SADD cars "Honda"

SADD cars "BMW"

SISMEMBER cars "Ford" // 1

SISMEMBER cars "Chevy" // 0

SMEMBER cars // Honda BMW Ford

SCARD cars // 3

SMOVE cars mycars "Ford"

SMEMBER cars // Honda BMW

SMEMBER mycars // Ford

SRAM cars "BMW"

SMEMBER cars // Honda

ZADD users 1980 "Brad"

ZADD users 1975 "Jen"

ZADD users 1990 "Mike"

ZADD users 1990 "Kate"

ZRANK users "Mike" // 3

ZRANK users "Jen" // 0

ZRANK users "Brad" // 1

ZRANGE users 0 -1 // Jen Brad Kate Mike

ZINCRBY users 1 "Jen" // 1976

HSET user:brad name "Brad"

HSET user:brad email "brad@gmail.com"

HGET user:brad name

HGET user:brad email

HGETALL user:brad

HMSET user:john name "Jen" email "jen@yahoo.com" age "25"

HGETALL user:john

HKEYS user:john

HVAL user:john

HINCERBY user:john age 1 // 26

HDEL user:john age // 1

HLEN user:john // 2

SAVE

npx create-react-app .

npx create-react-app my-app --template redux

monitor PC {
    Object buffer;

    void produce(Object o){
        if(buffer != null){ // while
            empty.wait();
        }
        buffer = o;
        full.signal();
    }

    Object consume() {
        if(buffer == null) // while
            full.wait();
        Object temp = buffer;
        empty.signal();
        return temp;
    }
}

// Assumption: E < S < W (Signal and urgent wait)
monitor Semaphore {
    int permit;

    void acquire() {
        if(permit == 0){
            permitsAvailable.wait();
        } else {
            permit--;
        }
    }

    void release(){
        if(!permitAvailable.isEmpty()){
            permitsAvailable.signal();
        } else{
            permit++;
        }
    }
}

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main(int argc, char const *argv[])
{
	vector<int> iv = {1,2,3,4,5,6};

	vector<int> iv2(6);
	copy(iv.begin(), iv.end(), iv2.begin());
	// iv2: 1 2 3 4 5 6

	vector<int> iv3(3);
	copy_if(iv.begin(), iv.end(), iv3.begin(), [](int a){return a % 2 == 0;});
	// iv3: 2 4 6

	vector<int> iv4(5);
	copy_n(iv.begin(), 5, iv4.begin());
	// iv4: 1 2 3 4 5 6

	vector<int> iv5(6);
	copy_backward(iv.begin(), iv.end(), iv5.end());
	// iv5: 1 2 3 4 5 6

	return 0;
}

$font-stack: Helvetica, sans-serif;
$primary-color: #333;

body {
    font: 100% $font-stack;
    color: $primary-color;
}

.container {
    width: 100%;
}

article[role='main'] {
    float: left;
    width: 600px / 960px * 100%;
}

article[role='complementary'] {
    float: right;
    width: 300px / 960px * 100%;
}

$name: foo;
$attr: border;
p.#{$name} {
    #{$attr}-color: blue;
}