Trojan horsing Clojure with Javascript

Trojan Horse with me

http://developers.theguardian.com

Why
Javascript?

  • Dynamic
  • Uses maps as their main data structure
  • Derived from lisp
  • Use first order functions
  • Equally unpopular with "proper" language fans

So we're using Clojurescript, yeah?

No

  • Clojurescript is very opinionated
  • It doesn't fit Node-based build pipelines
  • It uses a library that virtually no-one knows
  • You have to take it whole, no cherry-picking

Wisp

A Clojure-like Lisp syntax

Wisp

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Javascript


(defn greet [name] (.concat "Hello " name))

(greet "Robert")

(defn currentSections
    [allSections, activeSections]
  (.filter list (fn [section]
    (.some activeSections
       (fn [activeSection]
         (identical?
           section.id activeSection.id))))))
var greet = exports.greet
    = function greet(name) {
        return 'Hello '.concat(name);
    };
greet('Robert');

var currentSections
    = exports.currentSections
    = function currentSections(
        allSections, activeSections) {
        return list.filter(
            function (section) {
            return activeSections.some(
                function (activeSection) {
                return section.id
                    === activeSection.id;
            });
        });
    };

The parens haven't gone away

Packaging (NPM)

Immutability

Mori

Compiled Clojurescript

Prefix notation

Includes quite a few Clojure standard library functions

Clojure data structures

ImmutableJS

Javascript

Prototype extension

Arrays-compatible interface

Feature comparable with Lo-Dash and Underscore

Influenced by Clojure data structures

 

Om

Love your library
not your language

Omniscient

  • Javascript
  • React
  • ImmutableJS
  • Immstruct

How does Om work?

  • Uses ReactJS to render an in-memory data structure
  • Uses immutable data structures to prevent unnecessary renders
  • Allows React components to be attached to sections of a data structure
  • Uses core.async to handle event changes

Immstruct

  • Wraps ImmutableJS structures
  • Provides an event model
  • Implements cursors

Cursors

 
var data = Immutable.fromJS({'person' :
    {'name' :
        {'first' : 'Robert', 'family' : 'Rees'}
    }
    , 'age' : 452});

var nameCursor = Cursor.from(data, ['person', 'name']);

nameCursor.update('first', function(name) {return name.toUpperCase();} );

data.getIn(['person', 'name', 'first']); // ROBERT

Event driven rendering

var immstruct = require('immstruct'),
  React = require('react');

var appData = immstruct({greeting: "Hello", guest: {name: ""}});

function render() {
    React.render(Component(appData.cursor()), documentElement);
}

render();

appData.on('next-animation-frame', render);

Wot no core.async?

Transducers?

Yes you can!

Why not Clojure?

  • Confident community
  • ES 6, transpilation and ES7
  • libraries > framework

Thank you

Blog: rrees.me

Twitter: rrees

http://slides.com/rrees/trojan-horsing-clojure-with-js

Trojan-horsing Clojure with Javascript

By Robert Rees

Trojan-horsing Clojure with Javascript

How to smuggle Clojure into your work with Javascript

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