krishnabhargav

type State<'S,'a> = 'S -> ('a * 'S)

module State = 
    let unit a : State<_,_> = fun s -> (a, s) 
    
    let map<'s,'a,'b> (f : 'a -> 'b) (r : State<'s,'a>) =
        fun s ->
            let a,next = r(s) 
            f(a), next

krishnabhargav

static T[] Rotate(int n, T[] arr) { var temp = new T[arr.Length]; for (int i = 0; i < arr.Length; i++) { var destIndex = i - n; if (destIndex < 0) { var mul = -1 * destIndex / arr.Length; destIndex = (arr.Length * mul) + destIndex;

krishnabhargav

git config --global diff.tool diffmerge
git config --global difftool.diffmerge.cmd 'c:/tools/diffmerge/sgdm.exe \"$LOCAL\" \"$REMOTE\"'
git config --global merge.tool diffmerge
git config --global mergetool.diffmerge.cmd 'c:/tools/diffmerge/sgdm.exe --merge --result=\"$MERGED\" \"$LOCAL\" \"$BASE\" \"$REMOTE\"'
git config --global mergetool.diffmerge.trustExitCode true

krishnabhargav

1) explain the life of an http request. 
2) what does the FLP result teach us? 
3) what is a byzantine failure? 
4) explain CRDTs
5) explain linearizability. 
6) how does DNS work? 
7) crash-stop vs crash-recovery? 
8) difference between soft and hard real time
9) model GC in an eventually consistent system 
10) discuss clock skew, NTP, and AWS vs metal 

krishnabhargav

let inline recordMetrics< ^T when ^T : (member MessageCountDetails : MessageCountDetails) 
                                 and ^T : (member Path : string)> (all : ^T seq) = 
        recordMetricsForPath (fun e -> (((^T : (member Path : string) e)))) all

krishnabhargav

learning/hello-paket/HelloPaket  master ✗                          103d ✖ ⚑ ◒
▶ wget https://github.com/fsprojects/Paket/releases/download/0.30.3/paket.bootstrapper.exe
--2015-02-23 21:20:58--  https://github.com/fsprojects/Paket/releases/download/0.30.3/paket.bootstrapper.exe
Resolving github.com... 192.30.252.131
Connecting to github.com|192.30.252.131|:443... connected.
HTTP request sent, awaiting response... 302 Found
Location: https://s3.amazonaws.com/github-cloud/releases/22755810/f2133dfe-bb80-11e4-9f9d-f777da134aed.exe?response-content-disposition=attachment%3B%20filename%3Dpaket.bootstrapper.exe&response-content-type=application/octet-stream&AWSAccessKeyId=AKIAISTNZFOVBIJMK3TQ&Expires=1424744518&Signature=v8wt6BYpfl2y0QOeTkmPQe18xUE%3D [following]
--2015-02-23 21:20:58--  https://s3.amazonaws.com/github-cloud/releases/22755810/f2133dfe-bb80-11e4-9f9d-f777da134aed.exe?response-content-disposition=attachment%3B%20filename%3Dpaket.bootstrapper.exe&response-content-type=application/octet-stream&AWSAccess

krishnabhargav

src/Unit-1/DoThis  master ✗                                          23h17m ◒
▶ ls -l
total 7456
-rw-r--r--  1 bhargava  staff      182 Feb 23 08:16 App.config
-rw-r--r--  1 bhargava  staff     1140 Feb 23 08:16 ConsoleReaderActor.cs
-rw-r--r--  1 bhargava  staff     1092 Feb 23 08:16 ConsoleWriterActor.cs
-rw-r--r--  1 bhargava  staff     1530 Feb 23 08:16 Program.cs
drwxr-xr-x  3 bhargava  staff      102 Feb 23 08:16 Properties
-rw-r--r--  1 bhargava  staff     2595 Feb 23 08:16 WinTail.csproj
-rw-r--r--  1 bhargava  staff      960 Feb 23 08:16 WinTail.sln

krishnabhargav

let rec gcd a b = match (a,b) with
			| (x,y) when x = y -> x
			| (x,y) when x > y -> gcd (x-y) y
			| (x,y)		   -> gcd x (y-x)

let lcm a b = a*b/(gcd a b)

krishnabhargav

let sizeOfFolder folder = 
    let allFiles = Directory.GetFiles(folder, "*.*", SearchOption.AllDirectories)
    let fileInfos = allFiles |> Array.map (fun x -> new FileInfo(x))
    let allSizes = fileInfos |> Array.map (fun x -> x.Length)
    Array.sum allSizes

///This version requires explicit type annotations in the lambda
let sizeOfFolder2 folder = 
    let allFiles  =  Directory.GetFiles(folder, "*.*", SearchOption.AllDirectories)
    let fileInfos =  Array.map (fun (x:string) -> new FileInfo(x)) allFiles

krishnabhargav

val sqlContext = new org.apache.spark.sql.SQLContext(sc); //sc is SparkContext
import sqlContext._

case class Person(name: String, age: Int)

val randomPeople = sc.parallelize(1 to 1000).map(i => Person("Yu_"+i,i))

randomPeople.registerAsTable("people")

val aged30 = sql("select * from people where age = 30")