shape_warrior_t

Just finished "version 0" for a very simple programming language yesterday, and I'm looking to work on "version 1" this weekend. Rust is truly fun to program in... although writing all the tests was not a very fun experience. But doing the work for that meant I was guaranteed to have a reasonably good grasp of the semantics by the time I finished.

Since it's Rust, there's no garbage collector -- heck, for this particular language, there's not even any memory allocation after startup. Instead you get a giant global array of "memory" to work with. The only data type is the 32-bit integer (and thus, using UTF-32 for strings is actually the """correct""" choice for this language). I'm using a vaguely Lisp-like syntax that revolves around {[a tree] formed from (brackets and whitespace)}... which was probably slightly easier to parse than more traditional syntax, but Rust's current lack of pattern matching "through" Vec (for example, letting you extract e from {a b [c (d e)] f} in one step) didn't always make it feel that way.

Nest up: adding while loops, exponentiation and bitwise operators, and most interestingly, string and character literals. (The char literals would just evaluate to their character codes, and string literals would only be usable in a specific write-to-memory construct.) And also expanding the standard library. I'd say "version 1" would really be the more properly "complete" version of the language. I also want to do a functional programming variation (ditching the global memory in favour of reference counted cons cells), and also the whole language is kind of just a stripped down version of another much bigger language half-formed in my head, but that's all probably for... not this weekend, at any rate.

Not very familiar with the libraries, and BB_C has already given a lot of more detailed feedback, but here are some small things:

• Even without rewriting get_files_in_dir as a single chain of method calls, you can still replace

  if dir.is_err() {  
      return None  
  };
  // use dir.unwrap()
  

  with

  let Ok(dir) = dir else {
      return None;
  };
  // use dir
  

  In general, if you can use if let or let else to pattern match, prefer that over unwrapping -- Clippy has a lint relating to this, actually.
• Although the formatting doesn't seem horrible, it doesn't seem like Rustfmt was used on it. You might want to make use of it for slightly more consistent formatting. I mainly noticed the lack of trailing commas, and the lack of semicolons after return None in get_files_in_dir.

The fact that x += y modifies lists in place might be surprising if you're expecting it to be exactly equivalent to x = x + y.

There was a recent langdev Stack Exchange question about this very topic. It's a bit trickier to design than it might seem at first.

Suppose we require a keyword -- say var -- before all binding patterns. This results in having to write things like
for (&(var x1, var y1, var z1), &(var x2, var y2, var z2)) in points.iter().tuple_windows() {},
which is quite a bit more verbose than the current
for (&(x1, y1, z1), &(x2, y2, z2)) in points.iter().tuple_windows() {}.
Not to mention you'll have to write let var x = 0; just to declare a variable, unless you redesign the language to allow you to just write var x = 0 (and if you do that, you'll also have to somehow support a coherent way to express if let Some(x) = arr.pop() {} and let Some(x) = arr.pop() else {todo!()}).

Suppose we require a keyword -- say const -- before all value-matching patterns that look like variables. Then, what's currently

match (left.next(), right.next()) {
    (Some(l), Some(r)) => {}
    (Some(l), None) => {}
    (None, Some(r)) => {}
    (None, None) => {}
}

turns into either the inconsistently ugly

match (left.next(), right.next()) {
    (Some(l), Some(r)) => {}
    (Some(l), const None) => {}
    (const None, Some(r)) => {}
    (const None, const None) => {}
}

or the even more verbose

match (left.next(), right.next()) {
    (const Some(l), const Some(r)) => {}
    (const Some(l), const None) => {}
    (const None, const Some(r)) => {}
    (const None, const None) => {}
}

and you always run the risk of forgetting a const and accidentally binding a new match-all variable named None -- the main footgun that syntactically distinguishing binding and value-matching patterns was meant to avoid in the first place.

Suppose we require a sigil such as $ before one type of pattern. Probably the best solution in my opinion, but that's one symbol that can no longer be used for other things in a pattern context. Also, if you're already using sigils before variable names for other purposes (I've been sketching out a language where a pointer variable $x can be auto-dereferenced by writing x), doubling up is really unpleasant.

...So I can understand why Rust chose to give the same, most concise possible syntax for both binding and value-matching patterns. At least compiler warnings (unused, non-snake-case variables) are there to provide some protection from accidentally turning one into the other.

I was thinking of the three legal states as:

• not logged in (null or {isAdmin: false, isLoggedIn: false})
• logged in as non-admin (false or {isAdmin: false, isLoggedIn: true})
• logged in as admin (true or {isAdmin: true, isLoggedIn: true})

which leaves {isAdmin: true, isLoggedIn: false} as an invalid, nonsensical state. (How would you know the user's an admin if they're not logged in?) Of course, in a different context, all four states could potentially be distinctly meaningful.

My preferred way of modelling this would probably be something like
role: "admin" | "regular" | "logged-out"
or
type Role = "admin" | "regular";
role: Role | null
depending on whether being logged out is a state on the same level as being a logged-in (non-)admin. In a language like Rust,
enum Role {Admin, Regular}
instead of just using strings.

I wouldn't consider performance here unless it clearly mattered, certainly not enough to use
role: number,
which is just about the least type-safe solution possible. Perhaps
role: typeof ADMIN | typeof REGULAR | typeof LOGGED_OUT
with appropriately defined constants might be okay, though.

Disclaimer: neither a professional programmer nor someone who regularly writes TypeScript as of now.

a === b returns true if a and b have the same type and are considered equal, and false otherwise. If a is null and b is a boolean, it will simply return false.

I would certainly rather see this than {isAdmin: bool; isLoggedIn: bool}. With boolean | null, at least illegal states are unrepresentable... even if the legal states are represented in an... interesting way.

Nice! Some feedback (on your Python, I don't speak Greek):

• In Python, the idiomatic way to name variables and functions is snake_case -- for example, greekTranslation should be greek_translation. (EDIT after seeing your most recent reply: good luck with that when it comes to Python :) )
• You're currently recomputing reverseTranslation every time the user requests an English-to-Greek translation. Unless you're planning to modify greekTranslation while the program is running, it would likely be more efficient to make reverseTranslation a global variable, computed just once at the start of the program.
• The control flow in the main program could be a bit more clear:
  • The condition in while optionSelection == <'practice'/'translation'> makes it look like optionSelection could change to something else inside the loop, yet you never do so. You could just write while True instead.
  • Instead of putting the "Please select either practice, translate, or exit" check up front, it would likely be more maintainable to add it as an else branch to the main if-elif-elif chain. That way, if you added in a new option, you would only have one place in the code to modify instead of two. (Also, instead of x != a and x != b and x != c, you could write x not in [a, b, c]).
  • Speaking of the if-elif-elif chain, you could replace it with a match statement, which would remove the repetitions of optionSelection ==.

Here's how I would write the control flow for the last section:

    optionSelection = input().strip().lower()
    match optionSelection:
        case 'practice':
            while True:
                practiceGreek()
                print('')
                print('Would you like another? [yes] [no]')
                print('')
                selection = input().strip().lower()
                print('')
                if selection != 'yes':
                    break
        case 'translate':
            while True:
                translateToGreek()
                print('')
                print('Would you like to translate another phrase? [yes] [no]')
                print('')
                selection = input().strip().lower()
                print('')
                if selection != 'yes':
                    break
        case 'exit':
            print('')
            print('Thank you for using the Greek Practice Program!')
            print('')
            sys.exit()
        case _:
            print('')
            print('Please select either practice, translate, or exit')
            print('')

(You could probably pull the while True loops into their own dedicated functions, actually.)

Hope that helps. Feel free to ask if any of this doesn't make sense.

Even regular Rust code is more "exciting" than Python in this regard, since you have a choice between self, &self, and &mut self. And occasionally mut self, &'a self, and even self: Box<Self>. All of which offer different semantics depending on what exactly you're trying to do.

You can get the exclusive behaviour with random.randrange. (Relevant Stack Overflow question with a somewhat interesting answer)

...Interesting idea. (And also interesting lore implications? Not that the game has any...)

My main thinking right now is: on startup, have the player on an empty field and force them to move (on both inner and outer "axes") onto a specially marked square (and press spacebar) to enter the main menu. (Controls and what they do will be explained in text.) This gets them accustomed to moving around and pressing the CONFIRM key for menuing.

Then have a special tutorial level to introduce the actual gameplay -- similar to the "real" levels, but much slower BPM and attacks are scripted instead of randomly chosen. I don't want to force anyone to complete the tutorial before entering the actual levels, but it would be the menu item that the player first lands on (aside from maybe the one for changing the controls to something less strange than A/D/J/L).

The tutorial level would require some more code, but at this point that might be worth it. (And also it would add another option for user-made custom levels if somehow people decide to edit those in.)

...Honestly, the one thing I'm most concerned about at the moment is getting players to read text, especially if it's off to the side to avoid covering the playfield.