forked from jmuraski/frp_presentation
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathindex.html
356 lines (209 loc) · 8.68 KB
/
index.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Functional Reactive Programming</title>
<meta name="description" content="An introduction to functional reactive programming.">
<meta name="author" content="Ted Naleid">
<meta name="author" content="Joe Muraski">
<meta name="apple-mobile-web-app-capable" content="yes" />
<meta name="apple-mobile-web-app-status-bar-style" content="black-translucent" />
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
<link rel="stylesheet" href="css/reveal.min.css">
<link rel="stylesheet" href="css/theme/custom.css" id="theme">
<!-- For syntax highlighting -->
<link rel="stylesheet" href="lib/css/zenburn.css">
<!-- If the query includes 'print-pdf', use the PDF print sheet -->
<script>
document.write( '<link rel="stylesheet" href="css/print/' + ( window.location.search.match( /print-pdf/gi ) ? 'pdf' : 'paper' ) + '.css" type="text/css" media="print">' );
</script>
<!--[if lt IE 9]>
<script src="lib/js/html5shiv.js"></script>
<![endif]-->
</head>
<body>
<div class="reveal">
<!-- Any section element inside of this container is displayed as a slide -->
<div class="slides">
<section data-markdown><script type="text/template">
# Functional Reactive Programming
by Ted Naleid <span class="amp">&</span> Joe Muraski
</script></section>
<section data-markdown> <script type="text/template">
## What is reactive programming?
</script> </section>
<section data-markdown> <script type="text/template">
## Well…there's a manifesto you can sign
<img src="/img/manifesto_small.png" width="700px"/>
</script> </section>
<section data-markdown> <script type="text/template">
## Ask 100 people what ‘reactive programming’ is…
</script> </section>
<section data-markdown> <script type="text/template">
## and you'll get a lot of buzzwords and handwaving
</script> </section>
<section data-markdown> <script type="text/template">
## So what is _functional_ reactive programming?
</script> </section>
<section data-markdown> <script type="text/template">
# In the beginning
</script> </section>
<section data-markdown> <script type="text/template">
## Getting a single value (synchronous, blocking)
getUser: User
</script> </section>
<section data-markdown> <script type="text/template">
## Easy to use and reason about, but it doesn't scale
</script> </section>
<section data-markdown> <script type="text/template">
## Get multiple values (synchronous, blocking)
getUsers: List[User]
</script> </section>
<section data-markdown> <script type="text/template">
## Now we get Iterators
(as documented by the Gang of Four)
</script> </section>
<section data-markdown> <script type="text/template">
## Composable data manipulation
val adults = users.filter(_.age > 17).sortBy(p => (p.lName, p.fName)).take(10)
</script> </section>
<section data-markdown> <script type="text/template">
## but we block until the full list is ready
</script> </section>
<section data-markdown> <script type="text/template">
## Callbacks/CPS let us work asynchronously
CPS - Continuation Passing Style
Call Back Hell
show easy then painful examples
</script> </section>
<section data-markdown> <script type="text/template">
## Futures/Promises help tame callback hell
(for single values)
</script> </section>
<section data-markdown> <script type="text/template">
## get single value (async)
getWidget: Future[Widget]
</script> </section>
<section data-markdown> <script type="text/template">
# What if you need a list of items asynchronously?
One way is to request the full list in an asynchronous way:
getWidgets: Future[Widget]
Server calculates list asynchronously and does a callback when it has the full list
Problems:
- need to wait for full list to come back (slow user experience)
- what if it's infinite (need to paginate, etc)
- what if it's a stream that updates? we need to poll for updates
</script> </section>
<section data-markdown> <script type="text/template">
# Observer pattern (as documented by the Gang of Four)
lets you register a callback
but then it is up to you to aggregate those into mutable lists and let consumers know that the list has been updated
</script> </section>
<section data-markdown> <script type="text/template">
# what if this happened?
You got your Iterator in my Observable! You got your Observable in my Iterator!
Photoshopped Reeses Peanut Butter Cups image
</script> </section>
<section data-markdown> <script type="text/template">
# their love child would be the Observable
getWidgets: Observable[Widget]
Allows you to asynchronously get
They are also composable, as we will see
</script> </section>
<section data-markdown> <script type="text/template">
## Marble diagrams explanation using something like drop
</script> </section>
<section data-markdown> <script type="text/template">
## Merge
</script> </section>
<section data-markdown> <script type="text/template">
## Zip
</script> </section>
<section data-markdown> <script type="text/template">
## Other functions
</script> </section>
<section data-markdown> <script type="text/template">
## Composition of functions
</script> </section>
<section data-markdown> <script type="text/template">
# How does this solve problems in the real world?
</script> </section>
<section data-markdown> <script type="text/template">
## Netflix example
netflix does this with their video API:
```scala
def getVideos(userId: Long): Observable[Map[String, Any]] =
videoService.getVideos(userId)
.take(10) // take the first 10, then auto-unsubscribe
.flatMap(video => {
val metadata = video.getMetaData(video) // async Map
val bookmark = videoService.getBookmark(video, userId) // async Map
val rating = videoService.getRating(video, userId) // async Map
Observable.zip(Observable(List(metadata, bookmark, rating): _*)).map {
case m :: b :: r :: Nil => Map("id" -> video.id) ++ m ++ b ++ r
}
})
//=> Map(id -> 1, rating -> *****, pos -> 1:33, length -> 2h, title -> Gravity)
```
That method composes 4 separate asynch calls into a List of 10 Maps
</script> </section>
<section data-markdown> <script type="text/template">
## Other examples
</script> </section>
<section data-markdown> <script type="text/template">
# Demo (shows merge, zip etc)
</script> </section>
<section data-markdown> <script type="text/template">
## Other similar tech that addresses the problems
</script> </section>
<section data-markdown> <script type="text/template">
# Scala - Actors (Akka)
</script> </section>
<section data-markdown> <script type="text/template">
# Go - Goroutines/Channels
</script> </section>
<section data-markdown> <script type="text/template">
# Clojure - core.async
</script> </section>
<section data-markdown> <script type="text/template">
# Groovy - Reactor
</script> </section>
<section data-markdown> <script type="text/template">
## Notice anything in common with those technologies?
</script> </section>
<section data-markdown> <script type="text/template">
## Notice anything in common with those technologies?
None of them are in Java, reasoning about asynchronous code is easier in more expressive languages
</script> </section>
<section data-markdown> <script type="text/template">
# Questions?
</script> </section>
</div>
</div>
<script src="lib/js/head.min.js"></script>
<script src="js/reveal.min.js"></script>
<script>
// Full list of configuration options available here:
// https://github.com/hakimel/reveal.js#configuration
Reveal.initialize({
controls: true,
progress: true,
history: true,
center: true,
// width: 1920,
// height: 1200,
theme: Reveal.getQueryHash().theme, // available themes are in /css/theme
transition: Reveal.getQueryHash().transition || 'fade', // default/cube/page/concave/zoom/linear/fade/none
// Optional libraries used to extend on reveal.js
dependencies: [
{ src: 'lib/js/classList.js', condition: function() { return !document.body.classList; } },
{ src: 'plugin/markdown/marked.js', condition: function() { return !!document.querySelector( '[data-markdown]' ); } },
{ src: 'plugin/markdown/markdown.js', condition: function() { return !!document.querySelector( '[data-markdown]' ); } },
{ src: 'plugin/highlight/highlight.js', async: true, callback: function() { hljs.initHighlightingOnLoad(); } },
{ src: 'plugin/zoom-js/zoom.js', async: true, condition: function() { return !!document.body.classList; } },
{ src: 'plugin/notes/notes.js', async: true, condition: function() { return !!document.body.classList; } }
]
});
</script>
</body>
</html>