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Rich Hickey: The Value of Values

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Re: Rich Hickey: The Value of Values

#31

Post by mattdeboard »

Munksgaard wrote: post #30
kamaal wrote: post #19

Great talk. Most of these talks on functional programming make perfect sense. These also look ideological superior. My only problem is Object oriented programming looks more pragmatic in the real world. There are libraries, tools, tutorials, help forums and a lot of other stuff out there which helps anybody who wants to start learning OO from to go from nothing to far places. You can't say the same thing about functi…

Clojure in Emacs with Slime is hardly a simple text editor. Emacs might be ancient, but that doesn't make it less powerful. There are also plenty of great documentation for Clojure, Programming Clojure is one, and the online documentation is excellent.

Well now, I love Clojure and write it for my hobby projects, but I have to disagree about the online documentation for it. Every command is documented, sure, but that doesn't make it excellent. For example, here's the doc for the `with-open' macro:

"bindings => [name init ...]

Evaluates body in a try expression with names bound to the values of the inits, and a finally clause that calls (.close name) on each name in reverse order."

I deliberately chose a bit of code that's actually pretty simple and straightforward; also, one that I know intimately. Now, knowing what `with-open' does as well as I do, this doc string almost makes sense on the first pass. But to the layman this is almost impenetrable. I've written a couple variants of this macro and I STILL have to read the docstring a couple of times to understand what it's saying.

The online docs are comprehensive but I would never use the term "excellent" to describe them.

Re: Rich Hickey: The Value of Values

#32

Post by sbov »

YuriNiyazov wrote: post #26
kamaal wrote: post #19

Great talk. Most of these talks on functional programming make perfect sense. These also look ideological superior. My only problem is Object oriented programming looks more pragmatic in the real world. There are libraries, tools, tutorials, help forums and a lot of other stuff out there which helps anybody who wants to start learning OO from to go from nothing to far places. You can't say the same thing about functi…

I just love it when people try to juxtapose "pragmatic" with "math-heavy". Obviously, in the real world no one ever uses math, all they do is print "Hello World" to the screen.

Unless you use Haskell, in which even printing "Hello World" to the screen is math heavy.

Re: Rich Hickey: The Value of Values

#33

Post by yason »

mickeyp wrote: post #27
hueyp wrote: post #20

Earlier quoted context omitted.

It wasn't a knock against relational databases. The issue is update in place. If you have a relational database that is append only there is no problem. He actually wrote one (datomic). The criticism of a primary key is again not anything against having primary keys, but that in a database that allows updates in place a primary key is meaningless. It is meaningless because it doesn't specify a value -- you pass a pri…

> you pass a primary key and it could be anything by the time the receiver gets around to using it. If instead the value was immutable passing a primary key would be fine. Not sure what you mean by receiver here -- receiver as in the database or another component in your software hierarchy? The best way to ensure that your data goes unchanged across atomically disparate events is to insist that (Oracle, which is what…

I think the parent meant the value vs. reference separation.

Consider that you create a record, give it a primary key N, then start referring to that value by the primary key and at some point make an update to the record, the same primary key now refers to another value. The primary key is just a reference pointer to a placeholder (=record) and depending on whatnot the value in the placeholder can change to anything. So, you have to be careful of what you mean by the primary key because it's just a reference, not a value. In the value paradigm your primary key would be a hash, like in git, that would forever be that one value instead of referring to some value.

Re: Rich Hickey: The Value of Values

#34

Post by Munksgaard »

mattdeboard wrote: post #31
Munksgaard wrote: post #30

Earlier quoted context omitted.

Clojure in Emacs with Slime is hardly a simple text editor. Emacs might be ancient, but that doesn't make it less powerful. There are also plenty of great documentation for Clojure, Programming Clojure is one, and the online documentation is excellent.

Well now, I love Clojure and write it for my hobby projects, but I have to disagree about the online documentation for it. Every command is documented, sure, but that doesn't make it excellent. For example, here's the doc for the `with-open' macro: "bindings => [name init ...] Evaluates body in a try expression with names bound to the values of the inits, and a finally clause that calls (.close name) on each name in…

Good point. The clojuredocs version[1] is a bit better, but you're right, it could be better.

[1] http://clojuredocs.org/clojure_core/clojure.core/with-open

Re: Rich Hickey: The Value of Values

#35

Post by sbov »

This video, along with many others I've watched from him, espouses the purity of data, and talks about not tangling data with functions (object orientation).

In this video, he seems to go along and say that values are great for software projects that use multiple languages, in part because values are universal meaning one doesn't need to translate classes into multiple languages.

However, regardless of whether you use an object oriented design or not, don't you usually have a set of functions you tend to perform on a set of data or values? For instance, you may not wrap your customer data behind a class and methods, but there are still going to be some rules related to all that data you're passing around. So in the multiple languages scenario, wouldn't you still have to translate those rules from language to language?

Re: Rich Hickey: The Value of Values

#36

Post by nickik »

jacoblyles wrote: post #4

Is there anywhere I can go to get a collection of useful programming videos? Somewhere that aggregates videos like these after they are uploaded?

You should be more clear what you want, programming videos can be anything from printing hallo world in java to theoretical computer sience where they dont even know how large the problems are.

Are you intressted in languages, compilers, algorithms, data structurs, parallism, concurency, databases, operating system, virtual maschines, garbage colleters, grafics or something more meta like the this 'value of value' video.

I can provide you links almost everything but im not going to do the work until you tell me what you want.

Re: Rich Hickey: The Value of Values

#37

Post by DeepDuh »

sbov wrote: post #35

This video, along with many others I've watched from him, espouses the purity of data, and talks about not tangling data with functions (object orientation). In this video, he seems to go along and say that values are great for software projects that use multiple languages, in part because values are universal meaning one doesn't need to translate classes into multiple languages. However, regardless of whether you us…

You would. The thing is that it's supposed to be easier and involving less code, since you don't need to port the interface boilerplate. At least that's how I understood it.

Re: Rich Hickey: The Value of Values

#38

Post by skardan »

I think there is another great example of value based programming we use every day even on small scale: unix pipes.

cat file | grep .... | wc

There are no complex protocols involved between cat, grep and wc - just passing around the value (now I am not talking about mutable files, directories etc).

I have seen very few systems which are as simple yet as flexible and versatile. Conventional wisdom says it is because unix is set of small utilities where each program does just one thing right. After watching the talk we should note that these utilities pass around text values.

If you want to build something as powerful and flexible as unix command line, you should think about value of decomposition as well as value of values :)

Re: Rich Hickey: The Value of Values

#39

Post by danenania »

Chris_Newton wrote: post #28
lrenn wrote: post #21

Earlier quoted context omitted.

> a time dimension (or, if you prefer, place-oriented programming) Place oriented is the opposite of having a time dimension. It means that at any time, the thing at that place might be different. This was done for your second argument, efficiency. The talk argues that if functional programming with values is efficient enough for you, than you shouldn't be writing object oriented software. Values on the other hand ab…

For the avoidance of doubt, when I’m talking about (not) doing away with a time dimension here, I mean from the perspective of the world changing over time as our program runs, not of associating values that effectively last forever with a certain point in time (as in purely functional data structures, version control systems, etc.). That is, even if we follow the current trend of adopting more ideas from functional…

I'm far from an expert on this topic, but it seems that you're still missing the main point--this talk is exactly about how to model time dependent data (immutable data), and how not to (mutable state, oo). Hickey definitely isn't advocating a system that can't change with time. Such a system would be pointless. He wants changes in state (which, naturally, occur on a time axis) to be represented by new values, not as in place, destructive updates of old values, as it's done in oo and currently popular databases.

If you look at the results of this approach in Datomic, I think you actually do see a design that treats time as much like a first-class citizen as it's ever been treated, in the sense that time essentially acts as a primary key, and developers are provided with a time machine that allows them easy and efficient access to any state that has existed in their data in the history of the application. (In theory, at least--I haven't personally tried Datomic).

Re: Rich Hickey: The Value of Values

#40

Post by mark_l_watson »

lrenn wrote: post #24
kamaal wrote: post #19

Great talk. Most of these talks on functional programming make perfect sense. These also look ideological superior. My only problem is Object oriented programming looks more pragmatic in the real world. There are libraries, tools, tutorials, help forums and a lot of other stuff out there which helps anybody who wants to start learning OO from to go from nothing to far places. You can't say the same thing about functi…

> The community is too elitist, the tutorials are math heavy. And the tools are too ancient. Having to use simple text editors and selling them as technologies used to build large applications is a contradictory philosophy. Careful. Statements like this only create more "elitists" by insulting people. Have you seen leiningen, Counter Clockwise, or La-Clojure? Part of the reason you need all that tooling is because of…

+1 the requirement for tooling is less. I switch between IntelliJ and Emacs for Clojure development, and tools don't hold me back.

I did a fair amount of Java GWT/SmartGWT development last year and having both client side Java code and server side code running in twin debuggers was handy, but really only crucial because of the complexity of the whole setup. That said, I only write simple web apps and web services in Clojure and Noir and perhaps that is why I don't feel that I need complex tools.

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