vncsna

set -e, -u, -o, -x pipefail

The set lines

• These lines deliberately cause your script to fail. Wait, what? Believe me, this is a good thing.
• With these settings, certain common errors will cause the script to immediately fail, explicitly and loudly. Otherwise, you can get hidden bugs that are discovered only when they blow up in production.

• set -euxo pipefail is short for:

set -e
set -u

TheAthlete

var Benchmark = require('benchmark');
var suite = new Benchmark.Suite;
 
let dominoes = [[1,1],[2,2],[1,1],[1,2],[1,2],[1,1]];
// add tests
suite.add('sort-join', function() {
  for (let d of dominoes) {
    [...d].sort((a, b) => a - b).join('');
  }
})

lbvf50mobile

from collections import deque

def doodledPassword(digits):
    n = len(digits)
    res = [deque(digits) for _ in range(n)]
    deque(map(lambda x: res[x[0]].rotate(-x[0]),[(x,y) for x,y in enumerate(res)]), 0)
    return [list(d) for d in res]

david-hoze

This is a reconstruction of http://www.roman10.net/2011/11/27/how-to-calculate-iptcpudp-checksumpart-2-implementation/ The site is gone so I took it from the archive for the sake of C Programming TCP Checksum's answer Enjoy! All credits go to https://github.com/roman10.

This is a follow up of the previous post, how to calculate IP/TCP/UDP checksum part 1 — theory.

IP Header Checksum Calculation Implementation

To calculate the IP checksum, one can use the code below,

IvanShamatov

# Component way of adding redis
# vendor/dry/system/components.rb
Dry::System.register_provider(
  :persistence,
  boot_path: Pathname(__dir__).join('components').realpath()
)

# vendor/dry/system/components/redis.rb
Dry::System.register_component(:redis, provider: :persistence) do
  init do

konstunn

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution:
    
    def deleteDuplicates(self, head: ListNode) -> ListNode:
        cur = head

konstunn

class Solution:
    def plusOne(self, digits: List[int]) -> List[int]:
        s = "".join([str(d) for d in digits])
        i = int(s)
        i = i + 1
        s = str(i)
        return [int(si) for si in s]
        

lbvf50mobile

Hi folks here I show some Ruby magic.

• a.group_by{|x| x} is similar to a.group_by(&:itself)
• a.group_by(&:itself) is a short cut for a.group_by(&:itself.to_proc)
• and a.group_by(&:itself.to_proc) just use new Proc a.group_by(&Proc.new{|o| o.send :itself})
• a.group_by(&Proc.new{|o| o.send :itself}) use & to treat a Proc as block like this a.group_by{|o| o.send :itself}
• a.group_by{|o| o.send :itself} here it's possible to substitute o.send :itself to o.itself: a.gruop_by{|o| o.itself}
• a.group_by{|o| o.itself} here o.itself it's just an o so it's equal to a.group_by{|o| o}
• Hey and the magic is a.group_by{|o| o} is just a a.group_by{|x| x}

cdesch

Cheat Sheets are greate but they are not a substitute for learning the framework and reading the documentation as we most certainly have not covered every potential example here. Please refer to the Rails Command Line Docs for more information.

Command Line Generator Info

Reference

You can get all of this information on the command line.

rails generate with no generator name will output a list of all available generators and some information about global options. rails generate GENERATOR --help will list the options that can be passed to the specified generator.

flaviocopes

package main

import (
	"strings"
)

func main() {
	strings.HasPrefix("foobar", "foo") // true
}