The Whiteboard

12:20 AM

@MichaelT that's the way, ruin his career before it even starts :P if he wanted something like that I could get him hired at my last place, at least they're good to work for if not allowing good work

Decent benefits, decent PTO, friendly people and nobody works overtime

Just brain dead culture with bad code and way too much fear to let anyone actually change the code

Jimmy Hoffa

1:12 AM

I'm starting to think I really don't like Rich Hickey

Every single misguided thing I hear about FP anymore seems to be somebody quoting that guy regarding Clojure like so long as you say and agree with these things you're doing FP, regardless of whether you're actually following any level of laws about it.

I'm sorry but using list comprehensions does not your code functional make

Jimmy Hoffa

1:32 AM

I feel bad. Glen Peterson's a nice and smart guy, and I just gave him a really big rant...

I just hope it comes off as logical sharing of knowledge as I was genuinely trying to do, rather than just an over the top castigation

I appreciate the effort, organization, and clear communication in this answer; but I have to take slight issue with some of the technicals. One of the keys as mentioned near the top is composition of functions, this goes back to why largely encapsulating functions inside of objects does not yield purpose: If a function is inside an object, it must be there to act on that object; and if it acts on that object it must be changing it's internals. Now I'll forgive that not everyone requires referential transparency or immutability, but if it changes the object in place it no longer need return it — Jimmy Hoffa 17 mins ago

And as soon as a function doesn't return a value, suddenly the function cannot be composed with others, and you lose all the abstraction of functional composition. You could have the function change the object in place and then return the object, but if it's doing this why not just make the function take the object as a parameter and free it from the confines of it's parent object? Freed from the parent object it will be able to work on other types as well, which is another important part of FP you're missing: Type abstraction. your forEachPasenger only works against passengers... — Jimmy Hoffa 15 mins ago

The reason you abstract things to map and reduce, and these functions are not bound to containing objects is so that they can be used on a myriad of types through parametric polymorphism. It's the conflagration of these varied abstractions which you don't find in the OOP languages that really defines FP and drives it to have value. It's not that laziness, referential transparency, immutability, or even the HM type system are necessary to create FP, those things are rather side effects of creating languages purposed for functional composition where functions can abstract over types generally — Jimmy Hoffa 12 mins ago

user20683

2:32 AM

@JimmyHoffa Things like mapping decorators to functions that will generate strings later

tylerl

5:20 AM

@JimmyHoffa I like the idea of FP containing a conflagration of varied abstractions. Abstractions tearing through the countryside and reducing all objects in its path to ash and soot.

user20683

@tylerl FP and OO are essentially inverses of each other

tylerl

@WorldEngineer eh?

I can see "fundamentally different", but how to you get from there to "inverse"?

user20683

@tylerl state control is the name of the game in both cases, in FP you define and chain the state together, passing it from one function to the next. In OO, you define the state as an internal structure of an object and then mutate it in place, getting reports on the state as defined by contract as you need them.

user20683

granted this is my warped brain that learned OO via equal parts Java and Objective C (the latter of which I've forgotten 95% of) and FP via Haskell mainly.

user20683

also it's terribly late

tylerl

5:32 AM

They definitely take very different approaches, if state were always represented by the fields of $this, then OO wouldn't have need for return

becuase all state would be implicit in the object itself

They're definitely very different design patterns, but not diametrically opposed, I don't think.

gnat

7:06 AM

guys I would appreciate your help...

299

A: Are answers that just contain links elsewhere really "good answers"?

I think that links are fantastic, but they should never be the only piece of information in your answer. An analogy would be if you are standing at 100 Main St. and you ask where 98 Main St. is. A good answer would be "It is the next building over". points at building If you instead inc...

marginal answers with links query shows less than 100 posts, could you please take a look at these? Posts in current query results are where I either feel these are OK, or can't make up my mind, or where my flags weren't actioned...

...While we're at it, I would like to say huge thanks to query author, @MichaelT - per my experience, it turned out incredibly accurate and sensitive in picking troublesome posts, both answers and questions

Matt D

7:40 AM

hgi folks

gnat

10:00 AM

interesting (and somewhat painful) to see how crappy answers come to the question having over-inflated collider exposure...

-1

A: Can a beginner in programming start learning game development?

i started like you with java. today, some years later, i still use object oriented stuff that i learned from the time i used java. java is greate but not as quick as other languages because it runs on a virtual machine. i would say learn some more java not to make anything just to get some experi...

-1

A: Can a beginner in programming start learning game development?

The first program I wrote in Java was a simple game of tic-tac-toe or naught’s and crosses. When learning to program you want to ensure that you don't try something too difficult too soon (don't try and write the next Tomb raider as your first project) but other than that. If you are interested...

-1

A: Can a beginner in programming start learning game development?

I recommend you see the basics first so that it won't take you long while starting development. Try to understand the basics like using loops and conditions statements in java before proceeding in any development. And try to be familiary with OOP freamwork first.

StuperUser

12:37 PM

Hi all, Is it possible to find all of the messages that I have starred in this chat room?

Yannis Rizos

12:52 PM

@StuperUser chat.stackexchange.com/rooms/info/21/the-whiteboard/…

and chat.stackexchange.com/rooms/info/21/the-whiteboard/… for your messages that were starred

Conversely, a far more effective way of bookmarking chat conversations is... bookmarks ;) There's a "create new bookmark" link in under "room▼" (top right, right under the room's tags).

user41796

1:32 PM

@GlenPeterson - welcome! @JimmyHoffa pokes in during the day. But you'll find this bit in the transcript of interest. chat.stackexchange.com/transcript/message/11702383#11702383

GlenPeterson

@GlenH7 - thanks!

@JimmyHoffa - Thanks for the compliments on the Whiteboard earlier. I enjoy constructive debate and greatly appreciate a clear, direct refutation of my statements. Your replies are DH5 or DH6 - it doesn't get any better than that. paulgraham.com/disagree.html

user41796

To the OP I can only suggest: Learn Haskell. If you truly want to learn FP, all the tutorials and nonsense in the world often leads you around the water to show you where the lake is, but that doesn't help you learn to swim. Learning Haskell is how everyone should disembark on their FP journey, it's akin to learning to swim by tossing you in the middle of the Atlantic, the only difference is for all your failures on the path, you'll never drown. So hang on tight and start paddling, with Haskell at your side you'll come to understand FP style better than any other softer language can teach. — Jimmy Hoffa 13 hours ago

user41796

^^^^ Who didn't see that one coming a mile away? @JimmyHoffa

GlenPeterson

@JimmyHoffa - I added a PS to my answer in response to this statement "If a function is inside an object, it must be there to act on that object; and if it acts on that object it must be changing it's internals." I agree that your accusation is typical of the practice of OOP (and of virtually every other kind of popular programming until maybe 3 years ago), but it is not an inherent aspect of OOP.

user41796

@GlenPeterson - Jimmy's known as our local Haskell evangelist in the chat room. I'm kind of surprised he didn't weigh in more on that particular OO => FP question. But he tends to hold back when solid answers are already in place

GlenPeterson

1:42 PM

@JimmyHoffa said, "You could have the function change the object in place, then return the object. If so, then why not make the function take the object as a parameter and free it from the confines of it's parent object? Freed from the parent object it will be able to work on other types as well." THX! This is actually the best answer I've heard to a question I posted a while back: programmers.stackexchange.com/questions/212515/…

@JimmyHoffa said, "The reason you abstract things to map and reduce." And there's the ultimate problem with Java. It does not provide abstractions suitable for use with immutability. Specifically, it's collections return something useless like "true" when you call add() instead of returning a new collection. It's functional object interface (which some call a functor) has no return type. Unless Java does an about-face, it will never be compatible with immutability.

@JimmyHoffa said, "functions are not bound to containing objects so they can be used on a myriad of types through parametric polymorphism. [that's why] functional composition [is] where functions can abstract over types generally." OK, but how does that work with type safety? Clojure seems to make this trade-off, providing really general functions at the expense of runtime safety.

maple_shaft

2:18 PM

I will never... never ... ever... even at gunpoint .... work at a company that even so much as entertains the notion of even considering Websphere Application Server

NEVER

AGAIN

COMPLETE

user41796

WAS had its day

maple_shaft

TOTAL

GARBAGE

user41796

not so much anymore

maple_shaft

No Glen... no... you don't understand...

you just don't understand how bad this is

user41796

I think the lads in Hursley started pursuing crap that just didn't make sense for the real world. And they were doing such crazy stuff to begin with that they couldn't bring the code back around to reality

user41796

2:19 PM

oh, I used to know some of the R&D devs for WAS....

maple_shaft

I just want to crawl in a hole and die

rather than have to try and fix another friggin environment issue

user41796

Websphere apps have that effect on folk. They are pretty brittle

user41796

I administered some MQ systems and tangentially touched some websphere AS stuff too

maple_shaft

I have opened 5 different PMRs just to upgrade JSF on a single application, and after following their advice a classloader issue has completely crashed the server

user41796

in my case, it was a pretty static environment, so I lucked out and didn't have to do much

user41796

2:22 PM

@maple_shaft go critical on L2 then. Truly - if you're not getting the support you need then convert the PMR to a critical situation

maple_shaft

That will have to be the next step then

charges should be brought against companies that peddle such unstable pieces of steaming refuse as this

user41796

IBM support really doesn't like having a PMR go critical, but such is life. Sometimes L2 and L3 simply can't get the resources you need to answer your question until it goes critical

GlenPeterson

@GlenH7 - I've dabbled in Haskell with the hope of understanding Monads. I still don't understand Monads. There are so many things I want to learn... I'm sure a Haskell pro would take offense at this, but I tend to think of Scala as Haskell for the JVM. Since I'm tied to the JVM, I've been exploring Scala instead.

user41796

@GlenPeterson they irony of there being an open Haskell discussion in the chat room and @JimmyHoffa NOT BEING INVOLVED is simply palpable....

user41796

I fear this day will go down in infamy for him

Jimmy Hoffa

2:24 PM

@GlenPeterson That's Clojure's approach, JavaScript does the same thing, it's indicative of dynamically typed FP languages which aren't uncommon, but I was trying to make clear the type system itself isn't really the hard-line that makes a language FP. The HM type system exists with the explicit purpose of giving static typing in the vain of allowing those highly general abstractions, ties back to Algorithm W

> Among the properties making HM so outstanding is completeness and its ability to deduce the most general type of a given program without the need of any type annotations or other hints supplied by the programmer. Algorithm W is a fast algorithm, performing type inference in almost linear time with respect to the size of the source, making it practically usable to type large programs.

(emphasis mine)

maple_shaft

lol

speak of the devil

user41796

@maple_shaft When you contact them on the 5th PMR, just politely request that you need to escalate the issue to sev 1 and to make it critical. Point out that having 5 PMRs to resolve an issue is unacceptable. Then point out that the last resolution crashed your server so you have lost use of the application.

user41796

The first item justifies the crit sit. The second item justifies the sev 1

user41796

and don't let them talk you into a lower severity until your server is up and running again.

Jimmy Hoffa

But the HM type system just rises as a side effect of trying to have those general abstractions and trying to get compile-time type checking, Clojure says rightly "FP doesn't need compile-time type checking" but Clojure doesn't mistake to say "Functions don't need to be composable by way of taking data as parameters and returning values"

user55340

2:26 PM

@GlenH7 I'm fairly sure that @JimmyHoffa has a haskell program that polls the chat room transcript for various mentions and sets off a gong when someone mentions a 'monad' or other key words. The only problem is that setting off a gong induces a state change...

Jimmy Hoffa

Clojure allows the dynamicism explicitly to allow that generalized abstraction

user41796

@MichaelT wretched, wretched state changes....

Jimmy Hoffa

►

user55340

@GlenH7 Its really quite limiting... imagine never being able to change your state out of, say, Colorado. Pure FP programmers can never change their state.

maple_shaft

@GlenH7 I have a critical deadline to resolve some proof of concept stuff then I absolutely must start on features. What this means is that I will have to use plain JSP's for my portal development as opposed to JSF which we are all experienced in. I am writing an architecture guide currently and I need to finish this before the dev team starts writing portlets. Without this document they will create an unmaintainable mess

Jimmy Hoffa

2:28 PM

@GlenPeterson I don't take it as an insult, I just personally disagree with the purpose of OO in FP, as many say they're orthogonal concepts and I don't disagree, but they're orthogonal like a bike and a car: You can have both, but when you do, one of them becomes pretty pointless

maple_shaft

While I agree with you on escalation... it is just easier for me to reinstall

Jimmy Hoffa

@MichaelT I have to rely on the runtime to mutate my state for me :(

user41796

@maple_shaft That's always a hard decision point. Just because you go critical doesn't guarantee you'll have a resolution in the timeframe you need. I would still escalate it, but hedge your bets by following the other path you mentioned. Keep in mind that if you don't go critical then they'll never really know what a steaming problem it was that you ran into

Jimmy Hoffa

@GlenH7 Is @maple_shaft about to become an unstoppable chain reaction? Don't do it @maple_shaft, just remember Three Mile Island!

user41796

"Back in the day", Support had to tally the total number of crit sits they had for the year. And they also ranked them by severity. Too many situations meant long talks with development about fixing the core issues.

user41796

2:32 PM

@JimmyHoffa past tense. He already changed state.

maple_shaft

@GlenH7 I am beyond caring what they know.... they obviously are ineffective at preventing such problems to begin with because they encourage the brain drain and technical debt that led them to this sorry pathetic state their ridiculous company has put themselves in

it just doesn't matter

user41796

@maple_shaft I have heard similar from many Websphere clients...

maple_shaft

The core fact remains their software is unusable, and the conspiracy theory part of me believes this is by design so that they can sell you yet another project

or sell you consultants

F***** ingrates

user41796

@maple_shaft nah, Global Services really doesn't have much feedback into the design cycle. You're safer just blaming the eggheads who created WAS to begin with.

Jimmy Hoffa

@GlenPeterson Scala doesn't seem a terrible language, but encapsulating a method in an object just lacks reason in FP because again, you're coupling that method with it's parent type then, and FP is all about generalizing methods and removing tight coupling. In procedural code we couple things sequentially, in OOP we couple things rationally, in FP we try to stop coupling things altogether.

maple_shaft

2:35 PM

The only part of me that cares is posting what I DO know in an SO question, (that can actually be indexed by Google unlike their horrible documentation sites) and self answer so that other people like me don't have to suffer through what I did...

user41796

Hursley makes some amazing, amazing stuff, as do the other R&D sites. But they are not ready for enterprise consumption out of the gate. And if you build up a monstrous application stack without the right foundation then you're doomed to see it collapse upon itself.

maple_shaft

but I am exhausted

Jimmy Hoffa

We're not used to thinking about a method inside an object as type coupling because it's the only way you can have a method in OOP, but it is coupling, and it is unnecessary, as well as it leads the horse to the water of non-compositional functions. As soon as your method is in an object, it's a really short step from saying 'well, I might as well just let it change the field in here instead of returning a new one since it's in here already...'

maple_shaft

and starting to NOT care about anybody but myself at the moment

user41796

dirty secret - I once wanted (and still kind of do) to work in an IBM R&D center. Nearly applied to work at Almaden.

Jimmy Hoffa

2:38 PM

@maple_shaft shit, at this point even venting the irradiated material won't stop you will it... the best we can hope for is a 40' thick cement sarcophogus. @GlenH7 get on it, you're the only real engineer around here...

maple_shaft

Sorry guys... just venting to prevent nuclear meltdown its the lesser of two evils

I will still probably get cancer from this though

user41796

@JimmyHoffa Cost of living is what stopped me from applying. They simply couldn't provide a large enough uplift to make it worth considering

Jimmy Hoffa

@GlenPeterson does this make sense what I'm saying? Am I just rambling madmanese? Here ye here ye! All have the lost buffalo within them! One need open their eyes, ears, and hair! Eat from the flesh of the electronics, the sky will bequeeth to you a woog-woog and we shall be slain, err saved, err slaved err RUN AWAY RUN AWAY...

GlenPeterson

@JimmyHoffa If you decouple all your functions from all but the most general type it could operate on, how do you organize your programs? Do you use files, or namespaces? Small programs sometimes use all globals, but large programs are all but impossible with that approach.

Jimmy Hoffa

@GlenPeterson Module systems vary, but are usually effectively like namespace organization

GlenPeterson

2:41 PM

@JimmyHoffa It takes me time to read things like the Wikipedia entry on the Hindley-Milner type system.

@JimmyHoffa I didn't think you were crazy until your madmanese post. :-)

Jimmy Hoffa

Note though, because multiple things are together in a module means nothing of their existence to interact with eachother so it's not like a class, they're just as you said, code-organization techniques. You may have modules with nothing but groups of functions that all work on a couple different general primitive types, and are organized together because they can be composed

or for any reason you wanted to organize them together really

the HM type system just refers to a type system based on what is commonly called Algebraic Data Types, Scala has those no?

Scala breaks down and fails to accomplish Algorithm W quality inferrence though because it's type system also has objects and non-ADT structures

GlenPeterson

@JimmyHoffa My experience is that when code is used in a way it was not intended to be used, it often breaks. Even for simple functions, it is very easy to make significant mistakes. Types are documentation of what the author was thinking and what they designed the function to handle. Once-again, this seems like trading wide reuse for safety.

Jimmy Hoffa

@GlenPeterson Sorry, referring to what exactly?

You're saying the HM type system gives safety but doesn't allow wide reuse?

GlenPeterson

@JimmyHoffa yes.

@JimmyHoffa No

@JimmyHoffa :-) Thinking...

Jimmy Hoffa

think about this ADT and function:
data Tree a = Node a (Tree a) (Tree a) | Nothing

treeMap :: (a -> b) -> Tree a -> Tree b
treeMap f (Nothing) = Nothing
treeMap f (Node val left right) = Node (f val) (treeMap f left) (treeMap f right)

Notice how it generalizes allowing to be used on a tree that has any type of value?

the type signature of treeMap :: just says (a -> b) so it's first param is a function that goes from any arbitrary type a, to any other arbitrary type b, and a Tree with values of that arbitrary type a (the part Tree a), and returns a Tree with values of the arbitrary type b (the last part of the sig saying Tree b)

the ADT definition is saying tree can be either of those things on each side of the | (you could add more |s to define more things the Tree could have been etc)

GlenPeterson

2:53 PM

@JimmyHoffa - yes. In Java this is done with "generics" which is a little bit like currying in the sense that you slap a type parameter on a function and get back a function that works only on that type. Because you've parameterized the type, you can make functions that work on any type, yet be type-safe.

Jimmy Hoffa

So think about that, and then think about the fact that, the treeMap can be generalized every further to where it doesn't even have to work on a Tree type, but any type that contains a type of a like the tree does:

fmap :: (a -> b) -> f a -> f b

GlenPeterson

@JimmyHoffa are you talking about duck-typing like Go? If a function requires a foo() method, you can pass anything with a foo() method as an argument?

Jimmy Hoffa

in this way it parameterizes the Tree itself as f, so it could be a List a, a Tree a, a Window a, anything, all of which fmappable so long as there's a definition for the fmap typeclass

It's similar to duck typing

not exactly the same though because: The function is outside of the type.

GlenPeterson

@JimmyHoffa - I think Scala calls type classes traits.

Jimmy Hoffa

So you could take a type someone else defined, define the fmap function for it and then it can be used in all the code that's written to fmap stuff

@GlenPeterson Yes.

The key being that they are defined separate from the type that they work with

This type of generalization which is even further than my initial quite general treeMap above is only possible when you accept implementing the functions outside of the types, so that the functions can generalize across many types

GlenPeterson

2:57 PM

@JimmyHoffa and mixed-in without changing the original argument to the function.

Jimmy Hoffa

So as I said above, putting a function inside a type is type coupling. FP is all about decoupling to the primitive base degree. Some do this using dynamicism, some do this using type systems like HM or in other varied ways, but the key is removing coupling allowing functions to be generalized, and generalized to the purpose that they may be composed arbitrarily and easily

GlenPeterson

@JimmyHoffa - even poor old Java can do this, but it requires that your function accept an interface. You may have to manually code a wrapper/converter class to implement that interface in a way that makes sense for the wrapped class. Anything you can write a sensible wrapper class for, you can pass to that function.

Jimmy Hoffa

I can compose filter with take with drop with map with fold, all without caring which type any of them are working on, it might be a tree or a list or a function

@GlenPeterson to an extend interfaces may mimic this, but even then you need to then implement a decorator that implements the interface, it's all very bulky and results in OO code that's hard to maintain

GlenPeterson

@JimmyHoffa - Yeah, though technically possible in a language like java, the effort of writing all the wrappers would make it completely impractical.

@JimmyHoffa - we could call this The Fallacy of Touring Completeness. Just because it's technically possible to do anything in one Touring complete language, doesn't mean that it's PRACTICAL.

@JimmyHoffa - But Java does not define OOP. It was merely a popular implementation of OOP when OOP was a huge fad. If we consider OOP to mean "allowing user-defined types" then I think we have something we don't have to hate. Something that isn't preventing arbitrary compositions with take, drop, map, and fold.

Jimmy Hoffa

@GlenH7 It's not really a question I was real interested in answering because converting OO code to FP code is more than a refactor, and more importantly the correct answer wouldn't answer his question, the answer he needs is to the question "How do I go about learning FP?" which isn't an appropriate Q for SE

GlenPeterson

3:06 PM

@JimmyHoffa - I mean, they talk about modeling with "verbs" instead of "nouns" in FP and that's great. And most of us have been living in a noun-dominated world for years and there deserves to be a reaction against that. But just as all-nouns is not the answer, I suspect that all verbs is not either. I mean, we all deal with data structures all the time.

Jimmy Hoffa

@GlenPeterson I prefer to take the common OOP relies on Encapsulation (of data and methods in an object), Inheritance (of data and methods from a parent object), (Subtypal/liskov) Polymorphism, and Abstraction (allowing methods to be specific as you get to lower types in the hierarchy)

GlenPeterson

@JimmyHoffa - there is nothing inherently bad about structured data. In fact, I would argue that structured data, like side effects, is necessary in order to get work done. There's a benefit to having the compiler inspect your data structure, or functional interfaces, or whatever and alert you when you try to plug a European 240V plug into a US 110V outlet. But I acknowledge that this safety comes with a cost.

Jimmy Hoffa

@GlenPeterson The HM type system is an implementation of structured data, it's the functions coupled to your types that is part and parcel of OOP that I reject from FP

GlenPeterson

@JimmyHoffa - So, I've been programming in OOP for years, and my personal experience is that Ihneritance is junk. Even Josh Bloch's item 16 says "favor composition over inheritence."

Jimmy Hoffa

@GlenPeterson codewonderings.blogspot.com/2012/09/what-about-inheritance.html

GlenPeterson

3:11 PM

@JimmyHoffa - Encapsulation has helped me out many times. Polymorphism is just what we are talking about. Actually, I would argue that we are just agreeing that Polymorphism is critical and that a broad, yet safe implementation is a huge win.

Jimmy Hoffa

I agree, but I find it most effective to frame OOP in that way to stop people from just saying "Every language is OOP!", which becomes a useless way of trying to identify distinctions and similes between approaches because that oh-so-common thought ends at "All design approaches are identical!"

@GlenPeterson I'm more argueing against Encapsulation, we agree about Polymorphism yes but encapsulation is counter to the abstraction of FP because FP's abstraction isn't based on subtypal polymorphism due to subtypal inheritance being nowhere to be seen (due to it being crap as you said)

GlenPeterson

@JimmyHoffa - the root of my current discontent goes back to a comment you made yesterday. The Clojure Camp sets up OOP as a straw man to take the blame for all the evils inherent in the Von Neuman architecture, and virtually all common programming practices. It's not fair, it confuses issues, and it distracts from meaningful discussion of good and bad programming techniques.

@JimmyHoffa - Encapsulation has saved my butt multiple times. Interface is a keyword in Java and other languages, but I'm going to use the word interface with a lower-case i to mean the concept of what one piece of code exposes to another piece of code, whether in the same code base, or across a network, or whatever. interfaces (lower-i) are everywhere.

Jimmy Hoffa

@GlenPeterson Well don't worry about that from me, I'm not standing up a straw man nor am I a card carrying clojure dev :P I don't blame OOP for all the ills, I just think within the framing of FP's more general more safe and easier to use abstractions, the OO approach loses use. I've written happy C# OOP code day in day out for enough years to not be claiming it a straw man, it put's food on my table and it works just fine for me to get fairly good quality applications written

GlenPeterson

@JimmyHoffa - With even a few thousand lines of code, interfaces are what allow you to cut apart your code in such a way that unrelated functions are not dependent on each other. This way, when you have to make a change in one area, there are other areas which are not affected at all.

Jimmy Hoffa

@GlenPeterson and data-based interfaces are great to have bundled with your implementations, but functions being bundled with the implementation are unnecessary, as soon as all the data of your varied implementations is exposed via an itnerface, you can make a single implementation of the necessary functions that works in the general case across all types and therefore having that function encapsulated with the varied data type implementations lacks purpose

GlenPeterson

3:20 PM

@JimmyHoffa - In this way, encapsulation is a wonderful thing because it allows you to decouple whole aspects of your application. If you have duck typing, or dynamic types, then you run into stuff like namespace collission, where one data structure uses :name or name() to represent one thing, and another data structure uses the same :name or name() to represent something else. Pass that to a general function and things break.

Jimmy Hoffa

I said structured data is good, HM type system has structured data like the tree I showed above, it's encapsulating functions into those types I disagree with

GlenPeterson

@JimmyHoffa - But why does a class or a type have to be more than a namespace to stick functions in?

@JimmyHoffa - even in Clojure, if you declare a function, it goes in the /user namespace or some such thing.

Jimmy Hoffa

@GlenPeterson Make all classes static and you don't have to, but then are you writing OOP anymore?

GlenPeterson

@JimmyHoffa - I'm saying that OOP does not prevent that.

Jimmy Hoffa

@GlenPeterson No, but it's counter to OOP to put all your functions in static classes and all your data in DTOs

GlenPeterson

3:23 PM

@JimmyHoffa - It's counter to any kind of popular programming that's more than 5 years old.

Jimmy Hoffa

2 mins ago, by GlenPeterson

@JimmyHoffa - But why does a class or a type have to be more than a namespace to stick functions in?

answered your own question :P

GlenPeterson

@JimmyHoffa - I think my answer is that a class or type can be just a namespace. It doesn't need to mutate, or extend, or be particularly data-specific.

@JimmyHoffa - where did I contradict myself?

Jimmy Hoffa

@GlenPeterson no it doesn't, but if you write your classes like that "It's counter to any kind of popular programming that's more than 5 years old."

GlenPeterson

@JimmyHoffa - yes, but a lot of my point is that these evils we've been talking about are not OOP evils, They are just old state-of-the-art evils.

Jimmy Hoffa

@GlenPeterson They can be avoided as we've said, but as you just said the approach to avoiding them is no longer writing OOP, not idiomatic or practical OOP anyway

OOP isn't evil, I write (what I think) is quality software in OOP every day, it tends to be pretty good flexible stuff that's easy to maintain and extend if I do say so myself

GlenPeterson

3:29 PM

@JimmyHoffa - So my point is that we have a new way of doing things that doesn't make obsolete only OOP, but most of the things that came before OOP as well. We aren't talking about shortcomings of OOP, rather OOP is simply old, and these are shortcomings of every old paradigm of programming of which OOP happens to be the most popular/recent. Mutable state is the basis of Von Neuman architecture which was invented in 1945.

Jimmy Hoffa

But to write FP is to choose an abstraction that no longer shows encapsulating data and methods together as worthwhile, and that encapsulation is core to OOP

GlenPeterson

@JimmyHoffa - It's not the fault of OOP that people in 1970 coming up with OOP assumed that mutability was a good thing.

Jimmy Hoffa

@GlenPeterson I think you're argueing with these card-carrying clojure folks you talked about :P I really don't think OOP is evil

GlenPeterson

@JimmyHoffa - Ah, but FP does not prevent encapsulation or interfaces.

@JimmyHoffa Because FP is so strong a tool, you can encapsulate with closures and with functions. Really, that's a strength of FP - that we can make better, yet more flexible abstractions.

@JimmyHoffa - I guess that to me, FP is just a bunch of awesome new techniques that solve problems we didn't even know we had 10 years ago. It makes a lot of OOP stuff less useful, but there are still some ideas that came into focus with OOP that are good. I suppose we are just drawing lines in our definition of OOP slightly differently, but it makes for interesting discussion.

@JimmyHoffa True.

@JimmyHoffa I'm going to have to focus on work for a while, but this has been a very interesting discussion. I'll definitely have to read more about Hindley-Milner and make an effort to learn more Haskell, at least enough to understand Peyton-Jones Monad paper.

Jimmy Hoffa

@GlenPeterson Same, carry on. Besides I think we've sufficiently assaulted the chat room heh

GlenPeterson

3:39 PM

@JimmyHoffa P.S. You too seem like a nice, and intelligent person. I look forward to our next discussion. I'm @GlenKPeterson on twitter. My email is my first name at organicdesign.org.

user55340

(btw, it makes me happy when we have fairly substantial perfectly P.SE discussions in chat...)

Jimmy Hoffa

I need a drink.

user55340

@JimmyHoffa I'm waiting for @YannisRizos to make a new profound comment so that we can pin it again. I'm hoping that @gnat doesn't provide evidence of his previous profound pinned comment.

Sparticus

5:01 PM

Holy stars going on in here. every other message

No, I am Sparticus.

No, I AM Sparticus

No, чto is Sparticus

No, seriously, I'm sparticus.

You guys are a bunch of .Net posers. I'm Sparticus and I <3 ruby

user55340

@Sparticus This is clear signs of brain damage. Likely caused by ruby treating the programmer's mind as an open class and metaprogramming in some weirdness language remappings whenever the person tries to say "ruby sucks". There is no other logical explanation for such statements.

Sparticus

5:14 PM

Man I love ruby so much. I find its ability to add individual methods to specific objects instead of each class to be so useful!

@MichaelT I have no clue what you're talking about

Jimmy Hoffa

@Sparticus Javascript does this (I assume you mean adding to instances instead of types)

Does Python not also allow this?

Sparticus

(I'm sure it does)

Jimmy Hoffa

In Javascript you can take an instance and just say
someInstance.Garrrr = function(pirate) {
    alert("The pirates name is " + pirate);
};

and now that instance has a new function but not it's type (you'd have to put it on someInstance.prototype for that)

Sparticus

Never done javascript

It has script in the title and damnit, I'm a programmer

I code, I don't script!

Holy shit... inheritance is bad?

Jimmy Hoffa

5:31 PM

@Sparticus Only if you've used it for years and found out subtypal inheritance is horrible

user41796

@Sparticus single inheritance is bad, multiple inheritance is the only way to do it right.

Jimmy Hoffa

@GlenH7 Right as a synonym for Fringe-Crazy? Yeah, that stands up.

Sparticus

I dont think java allows multiple inheritance

Jimmy Hoffa

@Sparticus whoa whoa whoa... you don't think it allows it?

An answer like that is going to get you not-hired sooo fast

user41796

@JimmyHoffa True believers get it. Proper and correct OOP is impossible without multiple inheritance. As evidenced by your lengthy conversation about FP vs. OOP, and as de facto evidence for why FP is seeing a resurgence of interest.

user41796

5:35 PM

And I'm glad none of you called my bluff since I was going to have a hard time keeping that line of trolling going

Jimmy Hoffa

"Can java do multiple inheritance?"
"Maybe?"

Maybe it fundamentally has a property inherent in the way the whole of the language works and all software in it would be defined, but maybe not? Maybe you should design all your code with that fundamental property in mind, or maybe you should design all your code with that fundamental property not in mind...

Sparticus

I didnt say maybe

I said I think that it allows it

in that I understand that my knowledge has limits

Jimmy Hoffa

@Sparticus Welcome to my bridge, how was your stay? Thankyou, come again.

user41796

You can bastardize MI into Java through interfaces. But it doesn't allow MI directly. AFAIK, C++ is one of the few "modern" languages that allow MI

Sparticus

because I'm not perfect, and if you're looking for the perfect person, I don't want to work for you anyway :)

Jimmy Hoffa

5:37 PM

@Sparticus Really though it is important to know if your language supports MI or not, though I wouldn't have expected you to know.

user41796

@Sparticus - I wouldn't worry about it. @JimmyHoffa only hires monads.

Jimmy Hoffa

@GlenH7 that's not really the same though with java because it can have multiple interfaces, but it doesn't inherit from multiple base classes

Sparticus

@GlenH7 He hires people? I thought that FP was stricly limited to academic usage

Jimmy Hoffa

@Sparticus I've said yay or nay on many interview candidates over the years :P

user41796

@JimmyHoffa hence "bastardize MI into Java" ... :-)

Jimmy Hoffa

5:39 PM

@GlenH7 it's not really though... it's not MI of any sort because again, it's not multiple inheritance and there's no way to make it so

user41796

Seriously though - are there any modern languages besides C++ that allow multiple inheritance? C# and Java don't.

Sparticus

I thought we were supposed to not use inheretince

Jimmy Hoffa

@GlenH7 Don't think so, I think it's left to the catch-all "I can do anything you can do [rest of this statement omitted]" of C++

user41796

@JimmyHoffa Well, where I was going to head with the conversation is that MI may not even be taught / discussed in classrooms since most languages don't support it and many view it as inherently evil.

user55340

@Sparticus I've done that once. I had an object that was a File that I had generated, but Redmine needed it to be an HTML Upload file that it defined... well, not so much needed it to be that class but respond to those methods that were in HTMLUploadFile or some such. So I just opened up the object and stuck all the methods that it was expecting in that object and went on. It made me feel dirty.

user41796

5:41 PM

MI may have gone the way of GOTO. At one point in time, it was a useful tool. But it was abused and the masses rallied against it.

Jimmy Hoffa

@GlenH7 Yeah, it's unlikely to be taught much anywhere because basically everyone says it is horrible, rightly so. It's one of those "Look what I can do!" things that only results in "Now I'm never actually going to do that, it was just an experiment" or "Holy crap why did I do that, this is maintenance hell and I hate my life now!"

user55340

@GlenH7 Perl does with its funky inheritance if you do OO Perl...

user55340

Apparently Python has some limited form of MI too...

Jimmy Hoffa

@MichaelT Yeah, but who does that?

user41796

@MichaelT Isn't that like OO in C? Yeah, it can be done, but do you really want to?

Jimmy Hoffa

5:42 PM

Oh right, Randall... like he counts..

user55340

perldoc.perl.org/5.12.2/Class/ISA.html

user55340

  @Food::Fishstick::ISA = qw(Food::Fish  Life::Fungus  Chemicals);
  @Food::Fish::ISA = qw(Food);
  @Food::ISA = qw(Matter);
  @Life::Fungus::ISA = qw(Life);
  @Chemicals::ISA = qw(Matter);
  @Life::ISA = qw(Matter);
  @Matter::ISA = qw();

user55340

So Fishstick searches for a method that it doesn't define in Food::Fish first, then Life::Fungus, and the Chemicals.

user41796

So I'll posit that it's not "fair" to expect a yearling to know whether Java or C# support MI when there isn't a reasonable expectation to believe they have been exposed to MI before. And yes, "exposed" really is the right term in this case. It's like a disease....

Sparticus

All I'm getting out of this is that I'd get docked on an interview for not knowing all about MI, even though if I used MI I would be an outcast

Awesome.

user55340

5:44 PM

@Sparticus You need to know about it to avoid problems where it might arise.

user41796

@Sparticus Actually, I'm trying to defend your (lack of) knowledge

Sparticus

@GlenH7 Well I thank you then.

user55340

People keep 'rediscovering' MI and thinking it a good idea at some point without realizing all the problems with it. If you understand it and all the problems, you will avoid solutions that depend upon it.

Sparticus

@MichaelT that sounds like a catch-all cop out to me...

with all due resepect, I think you could say that about any bad feature of any language

or any feature at all

user55340

Thats why people ask it... but the thing is you'll find people making two abstract classes, and then wishing that some other class could extend both of them (pardon my Java) without realizing the problems that that implies.

user41796

5:46 PM

@MichaelT I agree with what you're saying. But MI has evolved / devolved into an advanced programming concept that's not mentioned / taught at a Uni level. Whereas it once was. And while the greybeards know of it because we've been burned by it, the yearlings are blissfully unaware

Jimmy Hoffa

@MichaelT It's really easy to see how horrible it will be as soon as you think about it operationally from the constructor perspective you quickly realize "Fuck, that's going to be problematic.."

Sparticus

@MichaelT couldn't you just compose that third class with the first two?

user41796

It's like asking questions about the RedHat bootloader for the certification test when everyone has switched to using GRUB

Sparticus

(and I believe you meant two interfaces, not two abstract classes)

@GlenH7 You need to know about it to avoid problems where it might arise.

user41796

@Sparticus no, he meant classes. Behold the power of the dark side

user41796

5:49 PM

@Sparticus but those problems were eliminated by the mid to late nineties. And they showed up on certification exams 5 years after they were a non-issue

Sparticus

I can't say Ive tried to inherit an abstract class...

Jimmy Hoffa

No interviewer would expect you to know anything about MI, but it is a not-uncommon and worthwhile question about ones knowledge of their main language that basically exposes two things:
Do they understand the languages type system well enough to know how it fundamentally behaves?
and
Do they understand type systems well enough to know *of* arcane/uncommon concepts such as MI?

Nobody would ever ask specifics, but it's more of as "Has he heard of this at all or not?" Commonly people ask for an explanation of encapsulation, inheritance, polymorphism, etc for the same reason just to see if pe…

In your case, you don't have any particular depth of java knowledge so it doesn't really count

jozefg

Oh god help me, I'm starting to enjoy perl..

Sparticus

Get the gun.

jozefg

There's no need for that :) Anyone attempting to maintain my scripts will shoot me for free

Jimmy Hoffa

5:50 PM

@jozefg have a look at my comments here:

11

A: How to refactor an OO program into a functional one?

Definition of Functional Programming The introduction to The Joy of Clojure says the following: Functional programming is one of those computing terms that has a amorphous definition. If you ask 100 programmers for their definition, you’ll likely receive 100 different answers... Fun...

user41796

@JimmyHoffa I can agree with what you said there.

Sparticus

18 mins ago, by Jimmy Hoffa

An answer like that is going to get you not-hired sooo fast

Jimmy Hoffa

@Sparticus like I said, welcome to my bridge, how do you like the carpet?

@jozefg also am I crazy for hating the concept of functions inside of data types regarding FP?

Encapsulation in FP?

4 hours ago, 2 hours 3 minutes total – 153 messages, 5 users, 28 stars

Bookmarked 1 min ago by Jimmy Hoffa

jozefg

@JimmyHoffa I tend to agree. I certainly don't write tiny little programs in Haskell (<50 lines) because I'm worried that I can't handle mutability. It's because the abstractions in Haskell/Similar FP is just nicer.

Hmm.. Possibly. First class functions are certainly a nice thing. Things like the State, reader, and cont monads are all based around abstracting over function application

user55340

@jozefg Thats one of the things I like about perl - it can be fun to program in.

Jimmy Hoffa

5:55 PM

@MichaelT and it invites people to shoot you?

jozefg

@MichaelT It's like a drug, I know it's bad for me, but it's weirdly fun

@JimmyHoffa I want a version of Haskell that starts up fast. Then I can just write everything in Haskell and everything will be sunny and there will be unicorns

user55340

@jozefg How do you think its 'bad for you'?

user41796

@MichaelT It invites people to shoot him....

Jimmy Hoffa

@jozefg FPComplete? (what do you mean, Emacs isn't fast enough for you?)

jozefg

@MichaelT I understand enough about type systems that I find perl's appalling and the proliferation of globals is slightly terrifying. But if I've got <30 lines of code..

Jimmy Hoffa

5:58 PM

Or do you mean the compiled binary's runtime startup?

jozefg

@JimmyHoffa I mean an interpreter like GHCi or Hugs that starts up as fast as python

Jimmy Hoffa

@jozefg c-c,c-l is fast enough for me.. :)

...after the first time...

jozefg

@JimmyHoffa Yeah it's that 15-20 second first time

Oh hey I got pinned :D

Encapsulation in FP?

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