dineshba

if case .sugar = sugarcane.taste {              // if sugarcane.taste is `.sugar` then 
    print("yummmmy sugarcane")                  // enters into if
}
if case .salty(let value) = frenchFries.taste { // frenchFries.taste is .salty(10), so it matches
    if value < 10 {                             // the case and assign the value 10 to `value`
        print("manageable")                     // we can use the `value` inside the `if case`
    } else {
        print("impossible")
    }
}

dineshba

struct ComputerLab { // Computer Lab contains list of laptops.
    let laptops: [Laptop]
}
// we want to get the list of mac laptops

// Traditional way
var macLaptops: [Laptop] = []
for laptop in computerLab.laptops {
    if laptop.name.contains("Mac") {
        macLaptops.append(laptop)

dineshba

let fanNames = computerLab.laptops
    .filter({laptop in !laptop.name.contains("Mac") })
    .filter({laptop in laptop.fan != nil})
    .map({laptop in laptop.fan!.name})

// Simplified
let fanNames = computerLab.laptops
    .filter({laptop in !laptop.name.contains("Mac") })
    .compactMap({laptop in laptop.fan?.name})  //compactMap will filter out nil values by default

dineshba

var anyValue: Any          // If we don't know the type at compile time,
                           // we can use `Any`. It is mostly used for data 
                           // coming from network which can be type casted as below.

anyValue = "string value" // assinging string value

anyValue is String        // true
                          // type checking using `is` operator
if let stringValue = anyValue as? String { // if anyValue is castable to String, it will
    print(stringValue.uppercased())        // store in stringValue and enter into `if-let`

dineshba

class Dog {
    var name: String
    var weight: Int

    // constructor or initializer
    init(name: String, weight: Int) {
        self.name = name                  
        self.weight = weight
    }
}

dineshba

struct Cherry: Eatable {
  var taste: Taste = Taste.sweet
  func isBitter() -> Bool {
    return self.taste == .bitter  
  }
}
let 🍒 = Cherry() // literally we can have variable name like this🤓

struct Chilly: Eatable {
  var taste: Taste = Taste.spicy

dineshba

var optionalValue: Int?     
if let value = optionalValue { // unwraps optionalValue and assigns                                    
                               // it to variable named value
 print(value)                  // type of value = Int
else {
 print("not able to unwrap optionalValue as it is nil")
}
  
//Let's rewrite the sum function using if-let
func sum(_ optionalAugend: Int?, _ optionalAddend: Int?) -> Int? {

dineshba

# usage show_commit commit-sha
# usage show_commit HEAD

#!/bin/sh
show_tree() {
  spacing=$2
  printf "$spacing showing tree $1  \n"
  for one in $(git cat-file -p $1 | awk '{printf $2"--"$3 "\n"}'); do
    printf "$spacing $one \n"
  done;

dineshba

### custom shell prompt ###
parse_git_branch() {
    git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/ (\1)/'
}
PS1='\[\e[31;47m\]$(kubectl config current-context)\[\e[m\]\[\e[36;47m\]$(kubectl config view --minify --output 'jsonpath={..namespace}')\[\e[m\]\w\[\033[32m\]$(parse_git_branch)\[\033[00m\] \$ '

### cd dir interactively ###
alias godir='cd $(find ~/projects -type d -maxdepth 2 | fzf)'

### load tmux session interactively ###

dineshba

Learning
  - Technical
      - Use stderr and stdout properly (60% content for this 5w1h) (why do we need stderr, redirection, identify)
      - Use feature toggles
      - Write modular code in pkg dir so that anybody can import and use it (Eg helm, kubectl)
      - Easy dev setup (Makefile)
      - Logging at different log level (--debug flag)
      - 12 factor app (file, env, flag)
      - hyperfine for benchmark
  - NonTechnical