Programming |OT| Functional, Imperative, OOP, Cargo-Cult,... all are welcome!

vypek · Apr 23, 2019

So what I wound up doing last night for my Python issue was to install 2.7.16 on my PC and let it override 2.7.13 by write over the same folder I already had. Can't remove 2.7.13 from the list of programs for some reason though. Anyways, when I do "py -0" I can see that the launcher sees both the 2.7 and 3.7 versions I have installed. What is really interesting is that I don't need to specify the version when I run my scripts. The script based on 2.7 works from any folder without explicitly calling for 2.7. If I go directly into the folder where I store my scripts I can freely call for a version or the python.exe directory and then my script as an argument and it works that way. But if I am outside of that folder and I try to do that, I get an error. Not sure why though. It won't get in the way but I'll still be trying to figure out why that happens.

metaprogram said:
Make sure that in your scripts if you ever need to invoke python to run another script from within one of your scripts, you use `sys.executable` in the Popen() constructor to make sure your environment stays hermetic.

Thanks, I didn't consider this.

MotiD · Apr 24, 2019

I've started learning about inheritance and polymorphism in Java and I'm wondering something

If I have to classes with A being the super class and B being the subclass

If I create a reference variable of A to an object of B
A test = new B()
Let's say they both of a method public int calc(int a) that prints something but B is overloading the method with different parameters public int calc (int a, int b)
Why doesn't the compiler realize I'm overloading the method? It first checks A anyways to see that the method exists before going to B so if the method didn't exist in A at all it results in a compilation error or if it didn't exist in B but existed in A it would use the parent class method

Seems weird but I'm sure there's a logical explanation for why it works this way

SigmasonicX · Apr 24, 2019

MotiD said:
I've started learning about inheritance and polymorphism in Java and I'm wondering something

If I have to classes with A being the super class and B being the subclass

If I create a reference variable of A to an object of B
A test = new B()
Let's say they both of a method public int calc(int a) that prints something but B is overloading the method with different parameters public int calc (int a, int b)
Why doesn't the compiler realize I'm overloading the method? It first checks A anyways to see that the method exists before going to B so if the method didn't exist in A at all it results in a compilation error or if it didn't exist in B but existed in A it would use the parent class method

Seems weird but I'm sure there's a logical explanation for why it works this way

You created test as an A, so you only have access to A methods through test. If you want to use B methods, you'll have to cast test to B.

((B) test).useBMethod()

Sectorseven · Apr 25, 2019

Is it possible to combine two apps into one? Like if I want Hulu and Netflix in one app (I think Apple TV does something like this)?

Granadier · Apr 25, 2019

Sectorseven said:
Is it possible to combine two apps into one? Like if I want Hulu and Netflix in one app (I think Apple TV does something like this)?

No, Apple TV doesn't allow that and it's also not something that's possible.

Sectorseven · Apr 25, 2019

Granadier said:
No, Apple TV doesn't allow that and it's also not something that's possible.

I thought Apple TV lets you browse all the content from the different streaming services in one app. I guess that's what I'm asking. Not literally two apps in one, but like one central app where you can put all your login info and see all your content in one place.

Granadier · Apr 25, 2019

Sectorseven said:
I thought Apple TV lets you browse all the content from the different streaming services in one app. I guess that's what I'm asking. Not literally two apps in one, but like one central app where you can put all your login info and see all your content in one place.

Apple TV has a "TV" app that they own which will show you content that's available to watch through various services, but that's not the same as "combining two apps".

You could achieve the same behavior by just aggregating all of the available content from each service and determining if something is available that way. To actually view the content itself though you will always need to go into the specific app.

Sectorseven · Apr 25, 2019

Granadier said:
Apple TV has a "TV" app that they own which will show you content that's available to watch through various services, but that's not the same as "combining two apps".

You could achieve the same behavior by just aggregating all of the available content from each service and determining if something is available that way. To actually view the content itself though you will always need to go into the specific app.

So it doesn't actually track account information or what you have permission to watch? Like if you select a Netflix movie on Apple TV it will launch the Netflix app, and if you aren't a Netflix subscriber, I guess it just prompts you to sign up?

metaprogram · Apr 25, 2019

Sectorseven said:
So it doesn't actually track account information or what you have permission to watch? Like if you select a Netflix movie on Apple TV it will launch the Netflix app, and if you aren't a Netflix subscriber, I guess it just prompts you to sign up?

Amazon Fire TV kinda does this (not sure how this is related to programming though)

Granadier · Apr 25, 2019

Sectorseven said:
So it doesn't actually track account information or what you have permission to watch? Like if you select a Netflix movie on Apple TV it will launch the Netflix app, and if you aren't a Netflix subscriber, I guess it just prompts you to sign up?

Once the TV app has handed you off to the content provider app (Netflix, Hulu, etc.) it's up to them how they deal with you man

metaprogram said:
Amazon Fire TV kinda does this (not sure how this is related to programming though)

Yeah this. Kinda off-topic since it doesn't seem like the question is how this is achieved from a programming standpoint.

Sectorseven · Apr 25, 2019

Granadier said:
Once the TV app has handed you off to the content provider app (Netflix, Hulu, etc.) it's up to them how they deal with you man

Yeah this. Kinda off-topic since it doesn't seem like the question is how this is achieved from a programming standpoint.

I'm not really at the how point yet. I was just wondering if it was even feasible.

Granadier · Apr 25, 2019

Sectorseven said:
I'm not really at the how point yet. I was just wondering if it was even feasible.

> Is it possible to combine two apps into one?
No

> Can I link to other apps from within a different app?
Yes

If you're curious about the implementation look into URL schemes and deep-linking between tvOS apps. That's where all the magic lies.

Sectorseven · Apr 25, 2019

Granadier said:
> Is it possible to combine two apps into one?
No

> Can I link to other apps from within a different app?
Yes

If you're curious about the implementation look into URL schemes and deep-linking between tvOS apps. That's where all the magic lies.

This might be what I have been looking for, thanks.

Dave. · Apr 27, 2019

Megasoum said:
Hey guys quick question... Not necessarily exactly programming specific but anyway.

You guys have any good suggestions for video series on YouTube for UE4 or Unity tutorials?

I'm already experienced in C# and have a, very rusted, base in C++.

I know both companies have tutorials on their site but I'm looking for community made playlists.

Old post so maybe you've found lots good already, but I didn't see it answered. I've really enjoyed the youtube channel of Matthew Palaje, particularly the "Let's Create X" series. He has lots, this is the first:

They are blueprint focused in UE4 rather than C++, but I don't see that as a bad thing. They build on previous episodes so really should be watched in series.

Link to channel: https://www.youtube.com/channel/UCqPKRjVm36xmxu1OiegTWWg/videos

Have to scroll down a fair way until "2 years ago" to get to the above Genji vid and the start of the series.

Megasoum · Apr 27, 2019

Dave. said:
Old post so maybe you've found lots good already, but I didn't see it answered. I've really enjoyed the youtube channel of Matthew Palaje, particularly the "Let's Create X" series. He has lots, this is the first:

They are blueprint focused in UE4 rather than C++, but I don't see that as a bad thing. They build on previous episodes so really should be watched in series.

Link to channel: https://www.youtube.com/channel/UCqPKRjVm36xmxu1OiegTWWg/videos

Have to scroll down a fair way until "2 years ago" to get to the above Genji vid and the start of the series.

Cool thanks! I added his two "Let's Create" playlists to my Watch Later list

Anustart · Apr 27, 2019

Edit: Raging over.

vypek · Apr 29, 2019

I was messing around with Seleinum this weekend. Its really cool. I've barely scratched the surface and had some fun with it. Was executing javascript on pages, going through pages and clicking on stuff, sending username and password info to log into sites. Pretty fun stuff so far.

Dreamboum · Apr 30, 2019

Howdy folks I have to make Chess in OOP Java, any good resources out there? Also I'd need to make a GUI for it and I'm kinda lost. How much time do you think it would take me ?

I'm also struggling a lot with inheritance and polymorphism, does someone have resources that really helped them wrap their head around it? Thanks

Mr. Bad Example · Apr 30, 2019

Dreamboum said:
Howdy folks I have to make Chess in OOP Java, any good resources out there?

The Chess Programming Wiki is the best resource that I know of for this kind of thing.

-COOLIO- · Apr 30, 2019

i want to try my hand at creating simple music creation software. anyone have any ideas where i can start? books or online courses for digital audio programming with a focus in music creation?

ArnoldJRimmer · May 1, 2019

I have about 5 years + ( I had to check, I thought it was 4. I'm getting old!) experience with old and modern Angular guys, and I want to broaden my horizons. I've used React and Vue in the past, but mostly fixing bugs or adding small features (mostly on a node backend with some minor tweaks on the front end), so I don't have a really good feel for them and what they offer. I want to broaden my horizons and get REALLY good at at least one other front end framework. Possibly use it on an upcoming small to medium sized project at the end of this year.

What should I go for?

Theonik · May 2, 2019

-COOLIO- said:
i want to try my hand at creating simple music creation software. anyone have any ideas where i can start? books or online courses for digital audio programming with a focus in music creation?

What languages are you most familiar with? What direction do you wish to get into?
There is pretty decent audio APIs in web browsers these days.

-COOLIO- · May 2, 2019

Theonik said:
What languages are you most familiar with? What direction do you wish to get into?
There is pretty decent audio APIs in web browsers these days.

ideally i think i'd like to try creating a VR app for music creation, so i suppose javascript is probably no a go despite being my most familiar language.

i'm open to learning any language though. I have some familiarity with c, java, and python as well.

Dreamboum · May 2, 2019

Mr. Bad Example said:
The Chess Programming Wiki is the best resource that I know of for this kind of thing.

Thanks!

What would you folks say opened your eyes about OOP? I'm still struggling to grasp it fully, especially when it comes to encapsulation, overloading and polymorphism

Post Reply · May 2, 2019

Dreamboum said:
Thanks!

What would you folks say opened your eyes about OOP? I'm still struggling to grasp it fully, especially when it comes to encapsulation, overloading and polymorphism

Thinking about the concepts with real world analogies helped me when I first started learning OOP. Like, use literal objects and think about the different aspects of OOP with regards to those real world things.

Like encapsulation is keeping the inner workings of an object encapsulated inside that object (you don't want things that interact with the object to know about everything inside of the class... just what's necessary to accomplish some task). Think about a vending machine.

If you had to operate a bunch of cranks, levers and machinery yourself when you wanted to get a drink out of a vending machine, that would be a case of bad encapsulation. But in the real world, all you have to do is put money into the money slot and then select the drink you want and then the vending machine takes care of the rest. That's good encapsulation. It hides all of the stuff that's going on within that object when you ask the object to do things and it only presents its public interface, which in the case of the vending machine would be the money slot and buttons to select a drink.

ElectricKaibutsu · May 2, 2019

Hey everyone, I just wanted to pop in and say you can do it. I just got offered my first software developer job today and I'm so stoked to be starting on this career path at age 33. Four years ago I started on the help desk. After a year I moved into a Business Systems Analyst position. I started getting serious about learning software development a year ago. I got friendly with the developers and studied every night. I noticed some things we could do better at work and made some applications for that. I had some terrible interviews and then a good one which led to this job. I'm so happy to have found a career I want to do for the rest of my life. If I can do it, you can too. There are so many awesome resources out there. HackerRank was great for me for interviews btw.

HelloMeow · May 3, 2019

-COOLIO- said:
ideally i think i'd like to try creating a VR app for music creation, so i suppose javascript is probably no a go despite being my most familiar language.

i'm open to learning any language though. I have some familiarity with c, java, and python as well.

Your best bet would be Unity, since it has great VR support and there are several assets on the asset store that could help you, like synthesizers and sequencers.

DSP (digital signal processing) can be difficult to get into. This is the field you would need to be somewhat familiar with if you want to work with audio.

-COOLIO- · May 3, 2019

HelloMeow said:
Your best bet would be Unity, since it has great VR support and there are several assets on the asset store that could help you, like synthesizers and sequencers.

DSP (digital signal processing) can be difficult to get into. This is the field you would need to be somewhat familiar with if you want to work with audio.

great advice, thanks my dude.

MotiD · May 11, 2019

My Java course will end late next month and then I'm having my exam in early July
I've done great in all the assignments so far and I'm still confident as we're hitting the tougher subjects like algorithmic complexity, polymorphism and recursion but as this latest assignment is built with questions from exams of previous years I've noticed that as the questions get harder and rely more on logic and planning an algorithm and less on your Java knowledge, I'm relying more and more on the debugger which I obviously won't have in the exam

I find it hard to execute perfectly on the first try (as I'm sure many do, but this is what the exam requires) and even when I'm solving problems I keep thinking about how much time I've spent dealing with them and this won't do for the exam

I'm not sure what I'm actually asking? I guess for the exam itself I should prepare by solving exams from earlier years and do it with a pen and paper, but does anyone have any other tips to share with me?

ChrisR · May 11, 2019

Fuck internet explorer :(

Trying to decide if ES5 is easier to switch to or if I should just get Babel up and running in the old ass project I've started to update with typescript

Zevenberge · May 11, 2019

TypeScript is worth it. If you have any project that is past the scope of half a file, then type checking will help you greatly.
(As a plus, once you've got a compilation step up and running, you can simply transpile to an ancient version of Javascript and keep legacy compatibility.)

ChrisR · May 11, 2019

Zevenberge said:
TypeScript is worth it. If you have any project that is past the scope of half a file, then type checking will help you greatly.
(As a plus, once you've got a compilation step up and running, you can simply transpile to an ancient version of Javascript and keep legacy compatibility.)

Ya typescript is good, just sucks I still have to support IE for this project :(

ArnoldJRimmer · May 11, 2019

ChrisR said:
Fuck internet explorer :(

Trying to decide if ES5 is easier to switch to or if I should just get Babel up and running in the old ass project I've started to update with typescript

ChrisR said:
Ya typescript is good, just sucks I still have to support IE for this project :(

Cant you just set output to es5 in tsconfig?

ChrisR · May 11, 2019

ArnoldJRimmer said:
Cant you just set output to es5 in tsconfig?

I can, but then I lose a some of the stuff I had already been using... Trying to decide if I just target ES5 or go ES6+ and compile back just for IE.

Not much, but promises and find and a few other things have been great to use so far.

ArnoldJRimmer · May 12, 2019

ChrisR said:
I can, but then I lose a some of the stuff I had already been using... Trying to decide if I just target ES5 or go ES6+ and compile back just for IE.

Not much, but promises and find and a few other things have been great to use so far.

Ive had the pleasure of not having to worry about ie11 for far too long. ;)

I would set lib and target to es5 so that you get an error when the environment doesn't have a polyfill to support your code, then add it.

For promise es2015.promise should work.

Calderc · May 14, 2019

I'm currently going through Colt Steele's Web Developer Boot Camp, does anyone have tips or pointers for the best way to approach it? Should I just run through the lectures and exercises or should I be taking detailed notes along the way?

milch · May 14, 2019

Why does it seem like hardcore Functional Programmers consider the value of stuff like IO Monads self evident?

I have been struggling to understand the ROI of going through all the hassle of a purely functional approach for months now, but in everything I read and watch, the motivation seems to be poor considering the complexity of it all.

I is stupid :-(

Post Reply · May 14, 2019

milch said:
Why does it seem like hardcore Functional Programmers consider the value of stuff like IO Monads self evident?

I have been struggling to understand the ROI of going through all the hassle of a purely functional approach for months now, but in everything I read and watch, the motivation seems to be poor considering the complexity of it all.

I is stupid :-(

I've picked up F# this year and REALLY like it. I think if you're coming from an object oriented background, F# is a good way to get into functional programming because it's a hybrid language that's functional first, but it allows you to still opt into the object oriented paradigm if you absolutely have to.

If you're looking for a good book to read that explains functional programming concepts, I'd highly recommend this one:
https://www.amazon.com/gp/product/1617293997/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

It focuses on F# though, but it helped make a lot of functional concepts clear to me.

MotiD · May 14, 2019

Is solving the water trapping problem really hard or am I really dumb? I've been trying to solve it for a week now, with varying degrees of success but never quite solving it.
I finally saw a solution from someone in my group class and realized I've been complicating it WAY too much. like way over the top.
Thing is, now I don't want to use his algorithm and still come up with my own solution.

It's supposed to be even easier since all numbers are assumed to be greater than 0, and I'm disappointed in myself I haven't figured it yet.

SigmasonicX · May 14, 2019

MotiD said:
Is solving the water trapping problem really hard or am I really dumb? I've been trying to solve it for a week now, with varying degrees of success but never quite solving it.
I finally saw a solution from someone in my group class and realized I've been complicating it WAY too much. like way over the top.
Thing is, now I don't want to use his algorithm and still come up with my own solution.

It's supposed to be even easier since all numbers are assumed to be greater than 0, and I'm disappointed in myself I haven't figured it yet.

My recommendation would be to figure it out manually for some example problems, then try to extrapolate from them. This is one problem where drawing it could help a lot.

One key thing with algorithm problems is that you can often scale them up based on versions with only two or three entries.

Deleted member 6582 · May 14, 2019

milch said:
Why does it seem like hardcore Functional Programmers consider the value of stuff like IO Monads self evident?

I have been struggling to understand the ROI of going through all the hassle of a purely functional approach for months now, but in everything I read and watch, the motivation seems to be poor considering the complexity of it all.

I is stupid :-(

The value is it's easier to manage the behavior of a piece of code. Basically, if values can only change in very controlled ways it allows you to more easily isolate it and understand its behavior removing many subtle classes of bugs (and then compose it in powerful ways). Monads aren't everything in FP though, Haskell is heavy with them but you can try other languages like the aforementioned F#, Ocaml (or it's more readable variant: Reason), Elm etc.

milch · May 15, 2019

Post Reply said:
I've picked up F# this year and REALLY like it. I think if you're coming from an object oriented background, F# is a good way to get into functional programming because it's a hybrid language that's functional first, but it allows you to still opt into the object oriented paradigm if you absolutely have to.

If you're looking for a good book to read that explains functional programming concepts, I'd highly recommend this one:
https://www.amazon.com/gp/product/1617293997/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

It focuses on F# though, but it helped make a lot of functional concepts clear to me.

Somnid said:
The value is it's easier to manage the behavior of a piece of code. Basically, if values can only change in very controlled ways it allows you to more easily isolate it and understand its behavior removing many subtle classes of bugs (and then compose it in powerful ways). Monads aren't everything in FP though, Haskell is heavy with them but you can try other languages like the aforementioned F#, Ocaml (or it's more readable variant: Reason), Elm etc.

I have been dabbling in Scala for a while (which I like a lot). Which I guess is a weird beast because it lets you mix and match FP and OOP to the degree you're comfortable with. And a lot of it makes immediate sense.

I would say where I am struggling is when it goes from standard Scala to libraries like Cats/Scalaz etc, which introduce more Haskell-ish stuff. I would assume a lot of the same rules and laws apply in standard Scala, but it's kinda hidden from the user and sometimes a pragmatic way is chosen. All the rather abstract Category Theory related stuff is really hard for me.

MotiD · May 18, 2019

SigmasonicX said:
My recommendation would be to figure it out manually for some example problems, then try to extrapolate from them. This is one problem where drawing it could help a lot.

One key thing with algorithm problems is that you can often scale them up based on versions with only two or three entries.

Yeah, that's what I've done for another question and it worked great. I've left the water trapping question for now and I'm moving on to recursion problems.
How exactly can I retain values through recursion calls without the use variables outside the scope of the recursive method? I am allowed to create additional methods to help solve the main problem

SigmasonicX · May 18, 2019

MotiD said:
How exactly can I retain values through recursion calls without the use variables outside the scope of the recursive method? I am allowed to create additional methods to help solve the main problem

Generally yes, but I don't know the restrictions of your problem.

MotiD · May 19, 2019

SigmasonicX said:
Generally yes, but I don't know the restrictions of your problem.

I was given the problem and the signature that only received one value.
I used overloading since I could create additional methods for help and managed to solve it that way. Thanks!

I have a general question for programmers here.. why is Java not used for game development?

mugurumakensei · May 19, 2019

MotiD said:
I was given the problem and the signature that only received one value.
I used overloading since I could create additional methods for help and managed to solve it that way. Thanks!

I have a general question for programmers here.. why is Java not used for game development?

1) Garbage Collection means non-deterministic performance. GC is improving though.
2) Requires an additional RT. Less of a problem on PC. Bigger problem on console due to licensing.
3) C++ continues to be a fair compromise between performance and abstraction. With recent versions of the C++ standard, it's really easy to write code with few bugs. As well, the C++ standards are not tied to a specific company.
4) it's not useful for scripting due to a fair amount of boilerplate code being necessary in order to run. Lua, Python, JavaScript, and/or a custom scripting language are normally sufficient for that purpose.

Mr.Mike · May 19, 2019

Also at this point there's a lot of momentum behind C++ in game development. Libraries are in C++, experienced developers know C++, existing code bases are in C++.

MotiD · May 22, 2019

mugurumakensei said:
1) Garbage Collection means non-deterministic performance. GC is improving though.
2) Requires an additional RT. Less of a problem on PC. Bigger problem on console due to licensing.
3) C++ continues to be a fair compromise between performance and abstraction. With recent versions of the C++ standard, it's really easy to write code with few bugs. As well, the C++ standards are not tied to a specific company.
4) it's not useful for scripting due to a fair amount of boilerplate code being necessary in order to run. Lua, Python, JavaScript, and/or a custom scripting language are normally sufficient for that purpose.

Mr.Mike said:
Also at this point there's a lot of momentum behind C++ in game development. Libraries are in C++, experienced developers know C++, existing code bases are in C++.

Thanks!

Another, unrelated question - Is there some website that has well known programming questions (like the water trapping problem, which to my understanding is pretty well known) that could be asked about in exams (and probably job interviews)? I know GeeksforGeeks for example has some of these but I'm looking for a list to go over in preparation for my exam in early July

Reven · May 23, 2019

MotiD said:
Thanks!

Another, unrelated question - Is there some website that has well known programming questions (like the water trapping problem, which to my understanding is pretty well known) that could be asked about in exams (and probably job interviews)? I know GeeksforGeeks for example has some of these but I'm looking for a list to go over in preparation for my exam in early July

HackerRank is a pretty good website for practicing those type of technical interview questions.

MotiD · May 24, 2019

Reven said:
HackerRank is a pretty good website for practicing those type of technical interview questions.

Thanks! Will have a look later

I have a question about recursion.. is my method considered recursive if it's calling itself but it does not fold back to previous calls? I have a method that's supposed to count and print something and it does so by calling itself and increasing 3 values according to some set of conditions, but the counting and printing is done with new calls (if the condition is met) and at the end I return the counter without folding back to each previous call

Programming |OT| Functional, Imperative, OOP, Cargo-Cult,... all are welcome!

9 Million Scovilles

Elizabeth, I’m coming to join you!