“Hey Underscore, You’re doing it

wrong”

I <3 _

So what’s wrong then?

Agenda

•Currying

•Composition

•Functors

•Random stuff

CurryingCurrying

Curried Function

“A function that will return a new function until it receives all it’s arguments”

...weird

Wu.js to the rescue!

(well, one function at least)

not weird

ExampleExample

ExampleFunction

alUnderscor

e

0 0

ExampleFunction

alUnderscor

e

1 0

ExampleFunction

alUnderscor

e

2 0

ExampleFunction

alUnderscor

e

3 0

underscore’s api prevents you from currying

Currying•Make generic functions - data is

gone

•Build new functions by applying args

•Much more concise definitions

•Make types “line up” for composition

CompositionComposition

Category Theory

“The mathematical theory of transforming values and crap”

*inaccurate definition

ExampleExample

ExampleFunction

alUnderscor

e

3 0

ExampleFunction

alUnderscor

e

4 0

ExampleFunction

alUnderscor

e

5 0

underscore promotes chain as the function

of choice.

Composition•Build new functions from other

functions

•Helps build generic programs w/o args

•Extremely high level coding

•Mathematically backed

FunctorsFunctors

ExampleExample

ExampleFunction

alUnderscor

e

5 0

ExampleFunction

alUnderscor

e

6 0

ExampleFunction

alUnderscor

e

7 0

underscore explicitly prevents

extending map

Functors/Typeclasses

•Change behavior without altering function open/closed principle

•Not just map - reduce, compose, etc

•Intuition and “non proprietary” api

•Free formulas

•Dynamic type safety?

In conclusionIn conclusion