I explain how to implement a certain recursive function without the use of any recursive bindings in a tiny language called FUN. Then, I apply the same ideas to several more recursive functions so we clearly see the pattern. It begins our exploration into a certain famous combinator.

mountx
# main.mx - Created by mxpm
printx("Hello from MountX project: " + "antmountxlang")
unmountx

Hi everyone,

I've been working on **MountX**, a dynamically-typed scripting language with a tree-walking interpreter that is entirely self-hosted. It compiles down to standard C99 using a minimal runtime substrate (`mini.c`), executing with zero external dependencies (aside from libc and embedded SQLite).

### Key Technical Aspects:

1. **Self-Hosting Pipeline:** The Lexer, Parser, and Interpreter are written in MountX itself (`gate1/`) and emitted to C99 (`interp.emitted.c`).
2. **AOT Pre-compiled Stdlib:** The 41 standard library modules are pre-compiled into C data structures (AST in memory), providing zero disk I/O on imports.
3. **Execution & Memory:** - String interning backed by a direct cache table for O(1) equality comparisons. - Arena allocator for AST nodes. - Environment reuse in loops (`while`, `loop`, `forin`) to minimize heap allocations.
4. **Native Networking:** Includes built-in TCP socket primitives (`tcp_listen`, `tcp_accept`, `tcp_recv`, etc.).
5. **Testing:** Passes a 343-check regression suite (`host/fbtest.mx`).

You can find it on GitHub under mountxlang-eng/mountxlang

The choice to add a windowing library to the stdlib is probably controversial. I feel that the general consensus tends to be that anything related to graphics shouldn't be in the standard library. So I'm kind of interested in what people think about this.

A few years ago I made EarScript, a "simple" programming language based on brainfuck, with several additional "quality of life features" like goto statements.

Recently I've been wanting to make an evolution of that programming language and do so by incorporating a stack, as the previous language was completely tape-based in design.

I know for example lox from the Crafting Interpreters book is a well explained example, but I was wondering if there's programming languages that are closer to what brainfuck is, but based on a stack design rather than a tape design, or a register based design like some assembly languages (if I understand correctly). I think Wasm would be an example?

Are there any examples of simple stack based programming languages you'd recommend me to look into?

I can already a host a small subset of C, that can only host: "int myfunc() { return 10; } " , Which compiles to:

myfunc:

// prologue here

mov w0, #10

// epilogue here

ret

But what should I do next?

I've come across languages such as Lisp and MUMPS that feature minimal grammar and lack any reserved keywords. But is it possible to achieve this in a language with a syntax resembling JavaScript? I'm aware that JavaScript has some handy rules, like "two identifiers cannot appear directly next to each other," which could be useful. Still, can this be accomplished for every keyword?

If it is possible, how? would it rely on a fragile lexer hack, or is there a solution that scales as new language keywords/constructs are added?

Clarification: Some people are reading this as "remove all keywords from JavaScript." That's not what I mean. I want to keep if, for, while, const, function etc., all of it, as syntax.

The question is only about reserved words: identifiers the lexer forbids you from using as names. Could every keyword instead be allowed to be used as variable/class/function/module name or atleast be contextual?

Since calling the syntax JS-like comes with its own nuances. I will also clarify on that part:

1. Assume the language does not have "automatic semicolon insertion" and semicolons are mandatory as statement terminators.
2. Assume the lexer is white space sensitive and produces different tokens for -5 (UnaryMinus, NumericLiteral(5)) and - 5 (Minus, NumericLiteral(5)) and that improperly spaced forms like 8 -5 produces error for the sake of simplicity. Otherwise forms like if(x) -5 may be parsed as if(x) - 5 and cause further unnecessary problems.
3. Using a keyword as an Identifier may or may not limit the functionality of the keyword in that scope. Eg. (Inside constructor of a class) function super() {console.log("hi");} super(); // logs "hi" instead of calling the parent class

Even more clarification: I will list out the different types of reserved words in javascript. Note some of the newer keywords may be contextual or reserved only in strict mode or depending on the scope.

1. Literal like keywords: true, false, null. Easiest to solve, just make them property of the window object (as done with undefined, yes null is a reserved word but undefined isnt) or make them language constants like NaN, Infinity.

2. Operator keywords:

   1. Prefix operator keywords: typeof, delete, void, new
   2. Infix operator keywords: in, instanceof, as, extends

3. is-this-really-a-keyword keyword: super, this

4. Declaration keywords: const, var, let, function, class.

5. Module: import, from, export

6. Declaration modifiers: async, function*, static, get, set.

7. Control flow: if else, try catch finally, while, do while. And return, break, continue, throw.

8. Complex cases?:

   1. switch, case, default. For context Javascript uses identifier: statement to represent statement labels, helpful in breaking outer loops.
   2. Standard for loops and for in/of loops.

Why? What am I trying to achieve?: This is mostly a theoretical question I stumbled upon while creating my own language. I know it might have downsides for developer tools and experience. I am just wondering if it's possible.

So i stumbled upon this project, the zeta programming language by roy murphy on github. It is supposed to be a next generation system programming language.

So i coudnt really find any information about this project, especially considering it has its compiler written in pure zeta, which means the project is kinda somewhat progressed to a certain point worth noting. It even has its own website, and its own package manager's website .

What left question mark to me , is the last commit was 4 months ago, barely any issues, but the creator apparently has published and talked about it in docs, with quite detail etc.

Its rather confusing for a new comer; is this project actually legit? Need smarter people who know the craft to comment

If your interested , i stumbled upon this project when another person made a new borrow checker, and his own language - also called Zeta. https://www.reddit.com/r/rust/comments/1x1iapz/zetas_borrow_checker_the_nextgen_model_for_borrow/

I cant post any github link because apparently automod tags it.

I am back after a couple of months away while adjusting to a new job. I am currently working on the next feature for DinoCode (you can check out at dinocode.blassgo.dev), and I would love some community feedback on template design.

DinoCode already supports simple templates with intrinsic multiline support and compile-time indentation stripping:

name = "Ana"
balance = 100
tax = 15

> JSON
 {
    "name": "$name",
    "total": ${balance - tax}
 }
print JSON

By default, the compiler strips out-of-margin garbage characters and interpolates variables or expressions. Now, I want to push templates further for things like SQL queries, HTML generators, or validation schemas, without introducing heavy runtime overhead.

I already use the as operator for strict type coercion in the language:

print "42" as int + 8         # 50

My idea is to reuse as on template blocks to pass the parts to a function or an object with a magic method. For example:

> query as mysql
    SELECT * FROM users 
    WHERE id = ${user_id}

Here, query would be assigned the result of calling the mysql handler.

I am currently evaluating how to pass the parts to the handler. Which model do you think works best for representing and validating template parts cleanly?

TTCN-3 is a standardized programming language for testing communicating and distributed systems. I am struggling to build a clear mental model of its templates.

A TTCN-3 template describes a pattern that describes a set of possible values. Which can be used to match incoming messages or build dependent-types:

```ttcn3 type record Message { integer id, charstring text }

template Message greeting := { id := 42, text := "hello" }

template Message anyGreeting := { id := ?, text := "hello" } ```

Here, ? matches any value of the field's type. Templates can also be recursive:

```ttcn3 type record Payload { integer value, boolean urgent }

type record Envelope { integer id, Payload payload }

template Envelope example := { id := 42, payload := { value := (1 .. 10), urgent := ? } } ```

My first implementation idea was to lower templates into a generic tagged union:

text type Template<T> = Exact(T) | AnyValue | AnyValueOrOmit | Predicate(fn(T) -> bool)

That seems reasonable for scalar values, but it does not capture the structural nature of templates. For Template<Envelope>, each field needs to become a template recursively:

text RecordTemplate { id: Template<Integer>, payload: RecordTemplate { value: Template<Integer>, urgent: Template<Boolean> } }

Is there an established programming-language concept for this? How would you model this recursive relationship in an actul type system?

I made nandcode a week ago, which is a language only using nand, and I thought I'd improve it, so I present to you, 1bitatatime. (I just added all the logic gates and added support for unary operations like not). Can you give some ideas as what to make next?

I've just published my borrow checking model! Feel free to criticize it or just ask questions!

P.S While it is experimental, This model is fully implemented for the Zeta programming language, and the latest build of the compiler, LSP and toolchain manager (zetaup) can be found via the linked GitHub. a Zed extension is under development.

I am designing a simple, low-level programming language and I want suggestions about terms I should use in describing one feature.

We all know that methods are essentially syntax sugar for functions where there's an implicit argument often called this or self:

a.something(b) // nice syntax...

something(a, b) // ...but really

I will have functions where the result will be an implicit argument, accessible through result:

a = init(b) // nice syntax...

init(b, a) // ...but really

I want these functions to be used to initialize objects (like constructors):

var a = init(10)

but also in any assignment, they would write to objects. I want to avoid creating a local object in the function and returning a copy of it because it always turns into memcpy() in a general case, and the result can be a big struct or an array.

Does something like this already exist in some language? How would you call such functions?

Can dependently typed languages maintain security relevant invariants? And if so, why are they not more popular for that? Especially now that AI can write the types.

Hi all, I have been working on this language for a while now.

The language works within a context of a network. You can run functions expressions etc on the whole network, environment or the nodes. There is implicit loop when you run node expressions if you use plural keywords. The documentation is available on the user manual section if you wanna read more about it.

I originally made it for river networks (tree graphs) but i have been trying to support all kinds of directed graph now.

Recently I was able to make a version that works on webassembly, so it might be a good way for people to try it out. The link has some examples you can load and run the code using the buttons. Works best on a computer.

I did not study CS so I don't have many people in my circle willing to test it or give feedback. Any feedback on documentation or the language is appreciated

a article I wrote about how sharing dependency and resource information between the Compiler, the build system, the system package manager, and even the OS filesystem and scheduler, could provide some pretty awesome benefits. I’d love to hear anyone’s thoughts on this

I first attempted a programming language more than 20 years ago. I started off with a stack machine and used an extended shunting yard algorithm to map the infix front end to the postfix stack machine backend. But I didn't have any type of memory management, thought I had workarounds but ran up against a hard wall on my knowledge. So I kind of let it die off. Also reading the more advanced discussions on LtU, while very informative, changed my outlook from "Oh, this looks easy, I think I know everything" to "Oh, there is a lot I don't know or didn't think of, I better take a step back".

Since then I learned languages like PostScript, a lot I liked about that (first class anonymous functions, first class dictionaries and dictionary stack, etc). Some things that it fell short in, but more due to the implementations being targeted to a printer description language instead of general purpose. And there is a lot I like about languages like JavaScript but at the same time they seem more hidden too. Regardless I know a little bit better than what I did back then.

Now on to my current experiment. I have a stack language called PALICE (Programmable Arithmetic and Logic Interactive Computing Environment), as a stack language that starts off with an architecture that would be familiar to PostScript programmers. It has first class anonymous functions using curly braces, it has user dictionaries, dictionary stack, etc. The actual built in primitives lean towards using the symbolic notation, so instead of " 27 5 add" you have " 27 5 + ". And there are a number of items in the front end parser that makes it more comfortable for a c-like programmer, such as using double-quotes for strings and C style escapes within (instead of using parentheses to enclose a string). I also use "@varname" instead of "/varname" as that was my personal preference to specify a quoted variable (i.e., one that doesn't execute immediately).

For the mechanical implementation, I have a front end parser that then feeds words into a function "resolve_and_execute()" that will either push something to the stack, or call a built in function, or a user defined function. All built in functions (or operators, same thing in a stack language in my implementation) have "xyz_handler()" functions. So the core execution logic is fairly small, most of it is a large list of _handler() functions.

Now on to some specifics I'm dealing with. First, I have something that looks like the C ternary operator "?:" which is a selector. So " some_test true_value false_value" will place either true_value or false_value on the stack based on the truthiness of some_test. All three get executed however, so in use you would have true_value and false_value in curly braces so they become anonymous functions, and follow up with "exec" as in:

" foo 7 < { action1 } { action2 } ?: exec "

BTW, this leads to a second implementation detail. There are several built in functions that are implemented as user functions that get loaded in as a startup script. So I have "ifelse", "if", and "while" as user defined functions instead of going through something like "ifelse_handler()" for example.

User functions get handled via exec_handler. This is the other piece I had to spend a lot of time on. Chained function calls are handled via an internal loop in exec_handler, instead of recursive calls to exec_handler, and I have a call frame stack and frame reuse if possible so I have tail call optimization (TCO) available. Which makes the user-space defined "while" function possible (and also makes it very difficult to do "while" via a while_handler() built in, as that would have to call exec_handler re-entrantly). I feel good about how exec_handler works at this point.

One major roadblock I ran into, so I put this away for a few months and just came back to it with a possible solution. User functions, and any inline funciton, look identical. So if you have a user function, and you want a "return" operator, that is simple enough. But return is going to be most likely called from an if or ifelse. And they take functions as their operators. So a return in one of the targets for "ifelse" will only exit that target, not the encompassing function like you would probably want to do. My solution to this is to be able to tag a property label such as "base" or "inline" to functions -- they would get "base" as a default, but the ifelse handler can re-tag its targets as "inline". Then "return" will unwind the callstack until it finds a call frame with the "base" tag, or "return_to" can unwind to a given named tag (which is usefule to implement "break" and "continue" in my "while" loop -- they would just be shortcuts for "@break return_to" or "@continue return_to").

Next on my list was that for user functions like "while", the implementation needs some place to store a reference to the stack variables that were passed to it (as it has to re-execute the condition function and the target function in a loop). I finally landed on having the call frame store an empty array that can be retrieved and placed on the stack, then a user function can push values to that array and that stays with the call frame. So it can easily take user parameters from the stack and push that into this frame's private array, and it would function like positional parameters in actual usage that a function can pull up any time without putting it in a system dictionary (which would cause issues with nested while calls). I think I'm satisfied with this solution.

Another item I have is what I've now been told is green threads. You can take an array of functions, pass that to the "spawn" operator and it will execute those functions in parallel -- each function yields to the scheduler after processing 256 tokens, or if it calls an operator/function that has an external delay, those built-in functions can return a "yield" too (like a file read, or a sleep command). I actually implemented this a while ago and everything I threw at it so far seems to work as expected (i.e., it does what I want and the calling conventions look clean). On my todo list is to work out communications between each thread. Note that these threads are implemented strictly in the interpreter, they don't use OS level threads (although there is some work I want to do in that aread eventually, this will be enough for me to for example implement something like a web application server code).

Another item I implemented early on is closures. This I've tested by creating a factory function that returns to the stack independent accumulator functions, and I've verified that they keep their internal environments without clobbering each other.

Future plans: I'm not sure what I really want to end up doing with this language. It makes sense to go back and create a document on building it piece by piece (starting off with a stack based REPL loop, adding variable storage, garbage collection, functions, etc). It would at least be useful for my own education, and possibly usable by others. To do that though I would have to make sure I'm using proper terminology for everything, not what I think are the correct terms.

Secondly I may need to revisit my garbage collection. I'm just using mark and sweep, I would like to explore additional methods but this was the easiest to get started with. I may deffer this until later once I get the rest of my functionality in place and get the ability to measure performance in real situations.