[Community feedback] Switch/Case patterns

[Olyno]

Hi everyone 👋🏻
We (developers of skript-parser) would love to know your opinion about a maybe new feature we will add: the switch case.

Like you probably know, Skript is a English-based language, so we are not sure about this syntax. Can you give us your opinion about it?

To give more precisions about what we're thinking about, I'm going to simply quote the @Mwexim's questions from #92:

I have a few discussion questions ready because I know some people will not agree with the implementation:

• Is this necessary? The syntax isn't English-like! Yes it is, and it is very useful in my opinion. I hate the fact that script never added something like this.
• I don't like EffCase. It is quite ugly... If enough people agree with this, I will revert the second commit. I added this as extra utility, but I can imagine this is a step too far in creating non-English syntax.
• I think allowing identical switch statements/multiple default ones should be prohibited. If enough people agree with this, I will change this as well.
• Default cases should always be placed at the end. Again, if enough people find this necessary, I'll change it.

Furthermore, this fixes some problems with restrictions in the ParserState and with Effects. There was also a small fix for the logger while parsing literal lists.
Feedback is always welcome.

I would like to add this question:

• Do you have any usage idea of this feature? If so what is it?

I would like to hear the community's opinion about it. Thanks to anyone who tell us their opinion 😃

[Ankoki]

I do think the switch case feature will be very very useful in a lot of cases, however it will be hard to think of a pattern which doesn't look really messy, the only thing i can think of is

for every value of %object%:
    if value is "HI":
        #code
    if value is "BYE":
        #code
    else:
        #code

where the else acts as default, i couldn't really see any other way this being implemented bar the way you have already PRed but definitely would like to see it happen as it would be really useful and if there's any better patterns i would love to see them :D I also believe that the default should definitely always be at the end, as its similar to an if, else if, else if, else:)

[WeeskyBDW]

in my opinion, it need to be implemented even if an another syntax is choosen, for adding a for of (Javscript) or for in (Python) equivalent

[Psekk]

How does every value of %object% work, object is singular :/ but I get whatchu mean :)

[Moderocky]

It depends what direction you want to take your new Skript language in.
Do you want it to be english-readable? If so, then it's probably not a good idea (at least not in the traditional form, you might be able to create some alternative way of phrasing it.)
Do you want it to be focused on being a programming language? If so, then yes, since it's a very common feature found in most languages.

The original Skript was never intended to be a fully-fledged feature-perfect programming language and its core features were:

1. Being usable by everyone - no knowledge of programming required
2. Being quick to use - no compiling or loading or boilerplate, just write something in a file and slap it in
3. Being able to do a wide variety of things
   (- This courtesy of Njol's original introduction to it)

Now 2. and 3. aren't terribly relevant here - but 1. is. Switch statements may be common in programming languages, but they aren't always very intuitive (at least without explanation.) This would detract from Skript's accessible and english-readable nature to an extent.

Now you've already done this with things like || and && operators, etc. so it looks like you're not really concerned about the original purpose anymore. That's absolutely fine, since what you're creating here is effectively a new language with a new purpose, so you get to choose what direction you want it to go in and what you want the core objectives to be, however it would be worth making these objectives clear now.

Do you want Skript to be a niche thing - a simple and english-based language? If so, I would personally recommend dropping switch and similar. I think they look inconsistent in the design of the language, and they don't actually add any new behaviour that can't be reproduced with existing things.

On the other hand, do you want this new Skript to be another scripting language? If so, add in switches and the other common language features, or it'll just end up being a feature-lite alternative.

[Olyno]

How do you personnally see the Skript's language? Like do you see it as a niche thing or a scripting language?

[Moderocky]

How do you personnally see the Skript's language? Like do you see it as a niche thing or a scripting language?

Hmm, difficult to say.
I think has a disadvantage as a scripting language in that it requires Java and the JVM to run, unless you're planning to somehow convert it into a native executable (maybe Graal or similar?) but those tend to end up as very bloated installable files once converted.

Personally, I think your best advantage is to market it as an english-readable thing, a very beginner-friendly language, since there isn't really anything well known that is similar to that (so you'd get the advantage of being pretty unique :) .)

The most similar well-known language would probably be Python I think - similar format, whitespace as a part of structure, etc. and I'm not sure Skript can really measure up to Python at all, being realistic.

At the end of the day, languages are in competition. Skript needs to have a reason to be used, or it won't be used.
Original Skript has this with Minecraft:

• Minecraft development is exclusively limited to Java, Skript gives a much simpler alternative
• There aren't really any other things like Skript that compare to it, which is why it's so popular - the user has NO alternative

But outside of Minecraft? There are dozens of available languages. Skript needs to have an "ecological niche" to be useful.

• How does Skript compare with Python? Python is objectively faster, but Skript is (or should be) easier to learn.
• How does Skript compare with Ruby? Ruby might have class structure, but Skript is much more intuitive and simpler.
• How does Skript compare with C/cpp/etc.? These languages are faster, but a lot harder to learn and require compiling. Skript doesn't, and it's easier to learn.
  With languages like Go and JavaScript, I see Skript's advantage as being that it has much simpler syntax, no complex symbols to learn. With Go the user has to learn to use symbols like := () {} * & whereas everything is words in Skript. We can read words.

In all these cases: Skript has the advantage of being simple and easy. Of being something quick to learn. You can pretty much read the code and understand what it's going to do. You don't need to google what := does, what the ~!^ operators do because it doesn't (I don't think) have them. Instead, it's spelled out. set x to y and send {this} to {that}.

That's what Skript does best. I think you would be wise to follow it :)

[Mwexim]

I think I agree with all your points on behalf of what we want to achieve with skript-parser. Personally, I think the first point can be extended to "Being useable by everyone while providing feature-rich syntax for more experienced developers", and that's exactly why I added this switch statement. This is also the approach we seem to be taking with the || and && operators: "Who cares if they are not English-like. Just don't use 'em if you're starting with Skript" (obviously not that literally).

We want to preserve as much English syntax as possible, and that's why I added the questions in my original PR. I don't really care that much about this topic personally, because I put productivity before anything else, but we have to make sure we are not going too far in this.

My conclusion, therefore, is that the switch statement is perfectly fine. I added match %object% as an alternative to it.

[Moderocky]

Very good, I support this.

I also appreciate that you keep the alternatives (like and instead of &&) - gives the user the choice :)

[Efnilite]

In my opinion it'd be quite a useful feature that would make writing code easier (because you don't have to repeat for example string is ... but you only have to write the value) and also because switch looks way more organized and clean than a if/else statement. I also personally don't think you have to stray far from the Java-style switch statement (except maybe the required break; is at the end)

switch %something%: # this could be changed to something more english-y but idk english sooo
    case "cheese":
         # some uesless stuf fidkfdfkdfj
    default:
         # the rest

Adding multiple cases for 1 answer might be a bit hard for users to understand (no offense lol) but adding support might be nice.

[Mwexim]

Adding multiple cases for 1 answer might be a bit hard for users to understand (no offense lol) but adding support might be nice.

Yeah, that was my concern as well. I don't really like the Java-approach to switch statements and I don't think they fit into Skript's thought-process.

I think limiting the number of default statements to 1 would be the first step.

[WeeskyBDW]

i was thought of this syntax

loop all entries of {mylistvar}:
    when "Marie": send "Hey Marie" to console
     
    when "Jonathan":
        add 1 to {employees.count}
        send "Hey Jonathan, you have 1 task to do for today" to console"
        
    by default:
        send "Hey Anonymous"
        

it's a ridiculus exemple but i haven't any else. We can also imagine add is after where to made it's more english

[Moderocky]

i was thought of this syntax

loop all entries of {mylistvar}:
    when "Marie": send "Hey Marie" to console
     
    when "Jonathan":
        add 1 to {employees.count}
        send "Hey Jonathan, you have 1 task to do for today" to console"
        
    by default:
        send "Hey Anonymous"
        

it's a ridiculus exemple but i haven't any else. We can also imagine add is after where to made it's more english

That's quite nice, you could also reduce it to a similar

for {myNumber}:

    when 1:

    when 2:

    when 3:

    otherwise:
        ...

[WeeskyBDW]

yes it can be, like i say above in responce of Ankoki, a equivalent of python for in.

[Olyno]

Seems good

[Mwexim]

This seems especially useful while staying English-like. I am in favour of adding this as an alternative to the current syntax (maybe even a replacement). Combining it with loops would be especially useful, but I don't know for sure if this is achievable in a great way.

[TheBentoBox]

The reason conversations like this are even needed is due to some being overly fixated on Skript being an "English-based language". People fiercely attach themselves to that idea such that they don't even want to add features that can potentially tread on it.

To me, the more important aspect of Skript is that it is beginner friendly, not that it's English-based. The latter contributes to the former without having to dictate what the language offers. Most new developers will naturally be able to ease into an English-based language more easily, but that doesn't mean we shouldn't include standard logical structures in the language. In fact, I'd consider it a disservice to those budding developers to not include all standard logical structures. I know many people who are now very trained developers who started with Skript. The more standard programming logic we can put in Skript to help teach those new devs, the better.

My take: definitely add it, and give it two main syntaxes. One can be the standard switch, case, ..., default for those that are already familiar with switch statements, then another English-based one to fit Skript's structure, e.g.:

based on %object%'s value:
    when it's %value%:
        # do case-specific stuff
    otherwise:
        # do default stuff

That syntax may not be perfect but you get the idea. There's no reason English-based and programming-standard syntaxes can't live in harmony.

[Ankoki]

I really like this syntax and the idea of having both tbf, having both makes the most sense to me as its beginner friendly and understandable for anyone who's used it in any other type of code before

[Moderocky]

The reason conversations like this are even needed is due to some being overly fixated on Skript being an "English-based language". People fiercely attach themselves to that idea such that they don't even want to add features that can potentially tread on it.

You say people are 'overly-fixated', but that's because it was Njol's original goal.
Large projects have goals and non-goals, that (are supposed to) dictate how they evolve.

In fact, Skript was not intended to be programming, but the opposite:

[To allow users] to easily modify how Minecraft works without programming anything

(- from Njol's original description.)

that they don't even want to add features that can potentially tread on it.

False, we want to make sure they're added in such a way that they don't tread on it.

Why switch in particular?
Switch adds no inherent functionality. The concept of switch came from a bit of metamathematics almost seventy years ago. It's been added to every programming language because it was always in the one that came before, and has basically been the same since C.

Switch is syntax sugar for languages that need syntax sugar.
Skript is entirely syntax sugar, so we can do a lot better.

There's no reason English-based and programming-standard syntaxes can't live in harmony.
You're correct, but we can do better here.

We can now create better methods of flow control. More intuitive methods! Easier methods!

Example:
Skript is almost unique in how it handles timings. wait 1 second in almost every other language will block the thread processing in order to preserve the happens-before relationship, a staple part of most modern languages. Skript, on the other hand, doesn't. It allows everything else to continue and waits only on the current action.

That is so much more intuitive to beginners. It makes perfect sense, and it's really useful.
Almost no other language has such simple control of timings.

So why can't we do the same with flow control? Create a more intuitive branching system that a beginner can understand. You're treating Skript like its only purpose is to be a training language that leads people into other languages, but it also has the capacity to be more than that.

[Mwexim]

For the ones still in this discussion, do you think something like this is plausible for Skript or should it be removed (and be dependent on sections):

switch {something}:
    case 1:
       print "First"
    case 2 then print "Second"

I am obviously referring to the inline-effect.
I added this because it seemed nice, but the more I looked at it, the less I like it. Anyone agree/disagree? Also, if you're in favour of, do you have any more syntax ideas?

[WeeskyBDW]

I agree

[Olyno]

Hi everyone, I just wanted to tell you that the syntax has been implemented as:

(switch|given|match) %object%

And

(case|when) %*objects%
([by] default|otherwise)

Thanks you to everyone who participated to this thread and I hope to see you on a new thread soon 😃