notes and todos

may_2025_thoughts.md

@@ -252,6 +252,7 @@ To reiterate the punch list that *I would have needed for Computer Class 1*:
 * [x] check loop forms against function calls: do they still work the way we want them to?
 * [x] tail call elimination
 * [x] stack traces in panics
+
 * [ ] actually good error messages
     - [ ] parsing
     - [ ] my memory is that validator messages are already good?
@@ -284,7 +285,51 @@ Just trying to get a sense of what needs to happen for CC2:
 * Why?
 * In the middle of doing TCO, looks like it works for `do` forms based on the bytecode, but I ran into these weird binding problems while trying to test that in the vm
 * Once that's put to bed, I believe TCO fully works
+
+_Edited to add: all the above is, I think, fixed._
+
 * But then I need to test it actually works in its intended use case: recursive calls
 * Which means I need to test recursive calls
 * And, once that's done, I think I have a COMPLETE SEMANTICALLY CORRECT INTERPRETER.
 * After that, jesus, it's time for base > prelude > test cases
+
+#### Later
+So this is my near-term TODO:
+
+* [ ] recursive calls
+    - [ ] direct recursive calls
+        * [ ] stash a function declaration before compiling the function, hang onto that declaration
+        * [ ] update that declaration to a definition after compiling the function
+    - [ ] mutual recursive
+        * [ ] check to make sure a function has already been declared, hang onto that declaration
+        * [ ] update that declaration to a definition after compiling the function...
+        * [ ] but BEFORE we close over any upvalues, so the function will be an upvalue for itself
+    - I suspect this can be done not using anything other than an index into a chunk's `constants` vec--no fancy memory swapping or anything; and also--done in the compiler rather than the VM.
+* [ ] getting to prelude
+    - [ ] `base` should load into Prelude
+    - [ ] write a mock prelude with a few key functions from real prelude
+    - [ ] a prelude should be loaded into every context
+    - [ ] the full prelude should run properly
+* [ ] packaging things up
+    - [ ] add a `to_json` method for values
+    - [ ] teach Rudus to speak our protocols (stdout and turtle graphics)
+    - [ ] there should be a Rust function that takes Ludus source and returns valid Ludus status json
+    - [ ] compile Rust to WASM
+    - [ ] wire Rust-based WASM into JS
+    - [ ] FINALLY, test Rudus against Ludus test cases
+
+And then: quality of life improvements:
+* [ ] improve validator
+    - [ ] Tuples may not be longer than n members
+    - [ ] Loops may not have splatterns
+    - [ ] Identify others
+    - [ ] Splats in functions must be the same arity, and greater than any explicit arity
+* [ ] actually good error messages
+    - [ ] parsing
+    - [ ] my memory is that validator messages are already good?
+    - [ ] panics, esp. no match panics
+        * [ ] panics should be able to refernce the line number where they fail
+        * [ ] that suggests that we need a mapping from bytecodes to AST nodes
+        * The way I had been planning on doing this is having a vec that moves in lockstep with bytecode that's just references to ast nodes, which are `'static`, so that shouldn't be too bad. But this is per-chunk, which means we need a reference to that vec in the VM. My sense is that what we want is actually a separate data structure that holds the AST nodes--we'll only need them in the sad path, which can be slow. 
+
+

src/compiler.rs

@@ -1336,8 +1336,8 @@ impl<'a> Compiler<'a> {
                 };
 
                 // TODO: check if the function is already declared, and pull out the relevant OnceCell if need be
-                let init_val = Value::Fn(Rc::new(lfn));
+                let the_fn = Value::Fn(Rc::new(lfn));
-                self.emit_constant(init_val);
+                self.emit_constant(the_fn);
                 self.bind(name);
 
                 for upvalue in upvalues {

src/main.rs

@@ -75,12 +75,7 @@ pub fn run(src: &'static str) {
 pub fn main() {
     env::set_var("RUST_BACKTRACE", "1");
     let src = "
-let whatevs = nil
+
-let mult_factor = 3
-fn mymult (x) -> mult (x, mult_factor)
-fn thing (x) -> mymult (x)
- 
-thing (2)
 ";
     run(src);
 }