Clojure night

Clojure Community Night

Aria Haghighi CTO

@aria42Saturday, October 5, 13

Eng @ Prismatic

Saturday, October 5, 13

Eng @ Prismatic

All Clojure in the back


Eng @ Prismatic

All Clojure in the back

Some Clojure in the front


<31. Why


<31. Why

2. Open

Source


<31. Why

2. Open

Source

3.What’s

needed


Why Clojure

<3


Programming to Behavior



EncapsulateThe

Object



Interface

EncapsulateThe

Object



At it’s best, OOP is about

coding to behavior, not

state or identity


Programming to Data


Programming to Data

Inherent data structures can

be used to derive the

structure of a program


Programming to Data


Programming to Data

Ins & Outs


Programming to Data

Ins & Outs

Represent


Programming to Data

Ins & Outs

Represent

Transform


The killer feature of Clojure isn’t that

it’s a functional language, but the

best data-oriented one

Programming to Data


Data Behavior


Data Behavior

sequences

mapsdefn

destructuring

macrosSaturday, October 5, 13

Data Behavior

sequences

mapsdefn

destructuring

macros

deftype

protocol

reify


Data Behavior

sequences

mapsdefn

destructuring

macros

records

multi-methods

deftype

protocol

reify


Data Behavior+

The crown of Clojure’s design is

the clean separation of data

and behavior


Open Source


Plumbing and Graphdata-oriented

composition and dependency

prismatic/plumbing


Graph: Overview


Graph: OverviewUnivariate statistics: Given data as double[] xs



m =1

n

nX

i=1

xi

m2 =1

n

nX

i=1

x

2i

v = m2 �m2



m =1

n

nX

i=1

xi

m2 =1

n

nX

i=1

x

2i

v = m2 �m2

xs

n

m2 m

v



xs

n

m2 m

v



xs

n

m2 m

v

(defn stats [{:keys [xs]}] (let [n (count xs) m (/ (sum xs) n) m2 (/ (sum sq xs) n) v (- m2 (* m m))] {:n n :m m :m2 m2 :v v}))


The Monster let(defn start [{:keys [a,z]}] (let [s1 (store a ...) s2 (store b ...) db (sql-db c) t2 (cron s2 db...)

... srv (server ...)] (fn shutdown [] (.stop srv) ... (.flush s1))))


The Monster let

dozens of parameters, not compositional

(defn start [{:keys [a,z]}] (let [s1 (store a ...) s2 (store b ...) db (sql-db c) t2 (cron s2 db...)



The Monster let

dozens of parameters, not compositional

structure of (de)composition is locked up in an opaque function

(defn start [{:keys [a,z]}] (let [s1 (store a ...) s2 (store b ...) db (sql-db c) t2 (cron s2 db...)



From let to Graph(defn stats [{:keys [xs]}] (let [n (count xs) m (/ (sum xs) n) m2 (/ (sum sq xs) n) v (- m2 (* m m))] {:n n :m m :m2 m2 :v v}))



xs

n

m2 m

v



{:n (fn [xs] (count xs)) :m (fn [xs n] (/ (sum xs) n)) :m2 (fn [xs n] (/ (sum sq xs) n)) :v (fn [m m2] (- m2 (* m m)))}

xs

n

m2 m

v



{:n (fn [xs] (count xs)) :m (fn [xs n] (/ (sum xs) n)) :m2 (fn [xs n] (/ (sum sq xs) n)) :v (fn [m m2] (- m2 (* m m)))}

kkkk

xs

n

m2 m

v


Example: API Service


Example: API Service

(def api-service (service {:service-name “api” :backend-port 42424 :server-threads 100} {:store1 (instance store {:type :s3 ...}) :memo (fnk [store1] {:resource ...}) ... :api-server (...)}))


sane DOM templating and manipulation

prismatic/dommy

Dommy


fast primitive array math

prismatic/hiphip

HipHip (Array)

w · x =nX

i=1

wixi


HipHip Examples


HipHip Examples Dot Product w · x =

nX

i=1

wixi



nX

i=1

wixi

Inner loop in machine learning



nX

i=1

wixi


argmax

`w · x`

prediction



nX

i=1

wixi


argmax

`w · x`

prediction

P (x;w) / exp{w · x}training


Dot Product w · x =nX

i=1

wixi

HipHip Examples



i=1

wixi

(defn dot-product [^doubles ws ^doubles xs] (areduce ws idx sum 0.0 (+ sum (* (aget ws idx) (aget xs idx))))

HipHip Examples



i=1

wixi

HipHip Examples



i=1

wixi

double dotProd(double[] ws, double[] xs) { double sum = 0.0; for (int i=0; i < xs.length; ++i) { sum += ws[i] * xs[i]; } return sum;}

HipHip Examples



i=1

wixi

HipHip Examples



i=1

wixi

(defn dot-product [ws xs] (hiphip.double/asum [w ws x xs] (* w x)))

HipHip Examples


declarative data description and

validation

prismatic/schema

Schema


What Clojure needs


Where’s my debugger!?!


MOAR Compiler Speed

(require 'api.deploy)

go get a coffee, it’s going to be a bit


Compiler Tooling

real IDE tools

Make Paredit a library


Multi-project support in Leiningen


Native Client Story


ThanksQuestions?


Clojure night

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