prevent rust panic on kill signal

may_2025_thoughts.md

@@ -1122,28 +1122,28 @@ That leaves the following list:
         * [ ] Model after the p5 keyboard input API
         * [ ] ludus keyboard API: `key_down?(), key_pressed?(), key_released?()`, key code values (use a dict) 
 * [a] Escape characters in strings: \n, \t, and \{,  \}.
-* [ ] `doc!` needs to print the patterns of a function.
+* [a] `doc!` needs to print the patterns of a function.
-* [ ] I need to return to the question of whether/how strings are ordered; do we use `at`, or do we want `char_at`? etc.
+* [a] I need to return to the question of whether/how strings are ordered; do we use `at`, or do we want `char_at`? etc.
     - MNL and I decided: yes, stings are indexable
     - [ ] implement `slice` and `at` and others for strings
 * [x] Automate this build process
 * [ ] Start testing against the cases in `ludus-test`
 * [ ] Systematically debug prelude
 * [ ] Bring it in function by function, testing each in turn
-* [ ] Animation hooked into the web frontend (Spacewar!)
+* [x] Animation hooked into the web frontend (Spacewar!)
 * [ ] Text input (Spacewar!)
 * [ ] ~Makey makey for alternate input?~
-* [ ] Saving and loading data into Ludus (perceptrons, dissociated press)
+* [x] Saving and loading data into Ludus (perceptrons, dissociated press)
 * [ ] Finding corpuses for Dissociated Press
-* [ ] improve validator
+* [a] improve validator
-    - [ ] Tuples may not be longer than n members
+    - [a] Tuples may not be longer than n members
-    - [ ] Loops may not have splatterns
+    - [a] Loops may not have splatterns
     - [ ] Identify others
-    - [ ] Splats in functions must be the same arity, and greater than any explicit arity
+    - [a] Splats in functions must be the same arity, and greater than any explicit arity
-* [ ] actually good error messages
+* [a] actually good error messages
-    - [ ] parsing
+    - [a] parsing
     - [ ] my memory is that validator messages are already good?
-    - [ ] panics, esp. no match panics
+    - [a] 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. 
@@ -1201,10 +1201,10 @@ After that:
         * [x] response: js->rust->ludus
     - [ ] `keyboard`
         * [ ] still working on how to represent this
-* [ ] hook this up to `web.ludus.dev`
+* [x] hook this up to `web.ludus.dev`
-* [ ] do some integration testing
+* [x] do some integration testing
     - [x] do synchronous programs still work?
-    - [ ] animations?
+    - [x] animations?
-    - [ ] read inputs?
+    - [x] read inputs?
-    - [ ] load url text?
+    - [x] load url text?
 

src/lib.rs

@@ -171,11 +171,12 @@ pub async fn ludus(src: String) -> String {
 
     let mut world = World::new(vm_chunk, prelude.clone(), DEBUG_SCRIPT_RUN);
     world.run().await;
-    let result = world.result.clone().unwrap();
+    let result = world.result.clone();
 
     let output = match result {
-        Ok(val) => val.show(),
+        Some(Ok(val)) => val.show(),
-        Err(panic) => format!("Ludus panicked! {panic}")
+        Some(Err(panic)) => format!("Ludus panicked! {panic}"),
+        None => "Ludus run terminated by user".to_string()
     };
     if DEBUG_SCRIPT_RUN {
         // vm.print_stack();