implement basic inheritance

README.md

@@ -23,3 +23,12 @@ popup.setLayout(layout: Layout | null)
 
 keyboard.setLayout(layout: Layout | null)
 
+
+TODO: multiple inheritance, diamond problem
+(it's technically allowed but the semantics aren't very good)
+
+MAYBE PLANNED: associated data (currently classes instances are
+singletons, which really simplifies ffi)
+
+NOT PLANNED: dynamic classes (i.e. updating classes after their
+definition). You can probably hack something up if you really need it.

defs.scm

@@ -10,7 +10,7 @@
 ; (define (kbd/load-font font-path) #f)
 
 (define-syntax self (syntax-rules () ((self func arg ...) (kbd/call kbd/this 'func arg ...))))
-(define-syntax super (syntax-rules () ((super func arg ...) (kbd/call (kbd/super kbd/this) 'func arg ...))))
+(define-syntax super (syntax-rules () ((super func arg ...) (kbd/call (kbd/super kbd/this 'func) 'func arg ...))))
 
 (define-syntax kbd/defmember
   (syntax-rules ()

src/keyboard.rs

@@ -24,10 +24,25 @@ pub struct PopupInfo<'b> {
     font_db: &'b mut FontDb,
 }
 
+#[derive(Clone, Debug)]
+struct Method<E: Engine> {
+    func: Option<E::Func>,
+    super_funcs: Vec<E::Func>,
+}
+
+impl<E: Engine> Default for Method<E> {
+    fn default() -> Self {
+        Self {
+            func: None,
+            super_funcs: Vec::new(),
+        }
+    }
+}
+
 #[derive(Clone, Debug)]
 pub struct Class<E: Engine> {
     pub supers: Vec<String>,
-    pub methods: HashMap<String, E::Func>,
+    pub methods: HashMap<String, Method<E>>,
 }
 
 impl<E: Engine> Default for Class<E> {
@@ -219,7 +234,7 @@ impl<E: Engine> Keyboard<E> {
                 .classes
                 .get_mut("en")
                 .and_then(|cls| cls.methods.get_mut("kbd/width-changed"))
-                .cloned()
+                .and_then(|x| x.func.clone())
             {
                 func.call(self, vec![Value::Symbol("en".into())]).unwrap();
             }

src/keyboard/script.rs

@@ -1,5 +1,8 @@
+use std::collections::HashMap;
+
 use crate::{
     graphics, image,
+    keyboard::Method,
     script::{Args, Engine, ErrorTrait, Func, Value},
 };
 
@@ -35,11 +38,14 @@ fn register<E: Engine>(
     };
     func.add_ref(vm);
     println!("register {cls:?} {name:?} {func:?}");
-    vm.classes
+    let meth = vm
+        .classes
         .entry(cls.into_owned())
         .or_default()
         .methods
-        .insert(name.into_owned(), func);
+        .entry(name.into_owned())
+        .or_default();
+    meth.func = Some(func);
     println!("done");
 
     Ok(Value::Null)
@@ -86,15 +92,36 @@ fn class_define<E: Engine>(
         .collect::<Result<Vec<_>, _>>()?;
     println!("register {cls:?} {supers:?}");
 
-    vm.classes
+    let mut meths = HashMap::<_, Method<_>>::new();
-        .entry(cls.into_owned())
+    // TODO: multiple inheritance ideally needs bfs rather than dfs
+    // and resolving diamonds requires deduplicating bases, and ideally toposorting them
+    // this is fine for when a single method has only a single super tho
+    for sup in &supers {
+        if let Some(sup) = vm.classes.get(sup) {
+            for (name, meth) in &sup.methods {
+                meths
+                    .entry(name.clone())
                     .or_default()
-        .supers
+                    .super_funcs
-        .extend(supers);
+                    .extend(meth.super_funcs.iter().chain(meth.func.iter()).cloned());
+            }
+        }
+    }
+    let entry = vm.classes.entry(cls.into_owned()).or_default();
+    entry.supers.extend(supers);
+    entry.methods.extend(meths);
     println!("done");
     Ok(Value::Null)
 }
 
+fn call_func<E: Engine>(
+    func: &mut E::Func,
+    engine: &mut E,
+    args: Vec<Value<E>>,
+) -> Result<Value<E>, E::Error> {
+    func.call(engine, args)
+}
+
 fn call<E: Engine>(
     vm: &mut Keyboard<E>,
     mut args: Args<Keyboard<E>>,
@@ -106,12 +133,27 @@ fn call<E: Engine>(
     let name = args
         .pop()
         .ok_or_else(|| ErrorTrait::invalid_argc("kbd/call"))?;
-    let Value::Symbol(cls) = cls else {
+    let (cls_s, func_idx) = match &cls {
+        Value::Symbol(cls) => (cls, None),
+        Value::RevArray(cls1) => match <&[_; 3]>::try_from(&cls1[..]) {
+            Ok([Value::Int(idx), Value::Symbol(super_name), Value::Symbol(cls)]) => {
+                (cls, Some((super_name, idx)))
+            }
+            _ => {
                 return Err(ErrorTrait::invalid_argt(
                     "kbd/call",
                     "symbol",
                     &format!("{cls:?}"),
                 ));
+            }
+        },
+        _ => {
+            return Err(ErrorTrait::invalid_argt(
+                "kbd/call",
+                "symbol",
+                &format!("{cls:?}"),
+            ));
+        }
     };
     let Value::Symbol(name) = name else {
         return Err(ErrorTrait::invalid_argt(
@@ -120,72 +162,79 @@ fn call<E: Engine>(
             &format!("{name:?}"),
         ));
     };
-    fn call_func<E: Engine>(
+    let is_super = matches!(func_idx, Some((x, _)) if x == &name);
-        func: &mut E::Func,
-        engine: &mut E,
-        args: Vec<Value<E>>,
-    ) -> Result<Value<E>, E::Error> {
-        func.call(engine, args)
-    }
     let func = vm
         .classes
-        .get_mut(cls.as_ref())
+        .get_mut(cls_s.as_ref())
-        .and_then(|cls| cls.methods.get_mut(name.as_ref()).cloned());
+        .and_then(|cls| cls.methods.get_mut(name.as_ref()))
+        .and_then(|x| match func_idx {
+            Some((_, idx)) if is_super => usize::try_from(*idx)
+                .ok()
+                .and_then(|idx| x.super_funcs.iter().rev().nth(idx))
+                .cloned(),
+            _ => x
+                .func
+                .iter()
+                .chain(x.super_funcs.iter().rev())
+                .next()
+                .cloned(),
+        });
     if let Some(mut func) = func {
-        args.push(Value::Symbol(cls));
+        args.push(cls);
         args.reverse();
         call_func(&mut func, vm, args)
     } else {
         Err(ErrorTrait::from_str(
             "kbd/call",
-            &format!("{cls}/{name} is not defined"),
+            &if is_super {
+                format!("super for {cls_s}/{name} not found")
+            } else {
+                format!("{cls_s}/{name} is not defined")
+            },
         ))
     }
 }
 
-fn set_user_data<E: Engine>(
+fn super_fn<E: Engine>(
-    vm: &mut Keyboard<E>,
+    _vm: &mut Keyboard<E>,
     args: Args<Keyboard<E>>,
 ) -> Result<Value<Keyboard<E>>, <Keyboard<E> as Engine>::Error> {
-    let Ok::<[Value<_>; 2], _>([k, mut v]) = args.try_into() else {
+    let Ok::<[Value<_>; 2], _>([cls, name]) = args.try_into() else {
-        return Err(ErrorTrait::invalid_argc("kbd/set-user-data"));
+        return Err(ErrorTrait::invalid_argc("kbd/super"));
     };
-    let Value::Symbol(k) = k else {
+    let (cls, func_idx) = match cls {
-        return Err(ErrorTrait::invalid_argt(
+        Value::Symbol(cls) => (cls, None),
-            "kbd/set-user-data",
+        Value::RevArray(cls1) => match <[_; 3]>::try_from(cls1) {
-            "symbol",
+            Ok([Value::Int(idx), Value::Symbol(super_name), Value::Symbol(cls)]) => {
-            &format!("{k:?}"),
+                (cls, Some((super_name, idx)))
-        ));
-    };
-    println!("setting user data {k:?} to {v:?}");
-    if let Some(mut val) = vm.user_data.insert(k.into_owned(), v.clone()) {
-        // FIXME: theoretically this can unref data that's referenced elsewhere
-        val.unref(vm);
             }
-    v.add_ref(vm);
+            _ => {
-    Ok(Value::Null)
+                return Err(ErrorTrait::from_str("kbd/super", "invalid class"));
-}
+            }
-
+        },
-fn get_user_data<E: Engine>(
+        _ => {
-    vm: &mut Keyboard<E>,
-    args: Args<Keyboard<E>>,
-) -> Result<Value<Keyboard<E>>, <Keyboard<E> as Engine>::Error> {
-    let Ok::<[Value<_>; 1], _>([k]) = args.try_into() else {
-        return Err(ErrorTrait::invalid_argc("kbd/get-user-data"));
-    };
-    let Value::Symbol(k) = k else {
             return Err(ErrorTrait::invalid_argt(
-            "kbd/get-user-data",
+                "kbd/super",
                 "symbol",
-            &format!("{k:?}"),
+                &format!("{cls:?}"),
+            ));
+        }
+    };
+    let Value::Symbol(name) = name else {
+        return Err(ErrorTrait::invalid_argt(
+            "kbd/super",
+            "symbol",
+            &format!("{name:?}"),
         ));
     };
-    println!("getting user data {k:?}");
+    Ok(match func_idx {
-    Ok(vm
+        Some((func, idx)) if func == name => Value::RevArray(vec![
-        .user_data
+            Value::Int(idx + 1),
-        .get(k.as_ref())
+            Value::Symbol(func),
-        .cloned()
+            Value::Symbol(cls),
-        .unwrap_or(Value::Bool(false)))
+        ]),
+        _ => Value::RevArray(vec![Value::Int(0), Value::Symbol(name), Value::Symbol(cls)]),
+    })
 }
 
 fn add_to_i64<E: Engine>(name: &str, a: Value<E>, b: Value<E>) -> Result<i64, E::Error> {
@@ -456,8 +505,6 @@ pub fn init_builtins<E: 'static + Engine>(engine: &mut Keyboard<E>) {
     engine.register_func("kbd/register", register);
     engine.register_func("kbd/class-define", class_define);
     engine.register_func("kbd/call", call);
-    engine.register_func("kbd/set-user-data", set_user_data);
-    engine.register_func("kbd/get-user-data", get_user_data);
     engine.register_func("kbd/make-text", make_text);
     engine.register(":round-corners", Value::new_symbol(":round-corners"));
     engine.register_func("kbd/make-rect", make_rect);
@@ -465,5 +512,6 @@ pub fn init_builtins<E: 'static + Engine>(engine: &mut Keyboard<E>) {
     engine.register_func("kbd/width", width);
     engine.register_func("kbd/load-font", load_font);
     engine.register_func("kbd/set-layout", set_layout);
+    engine.register_func("kbd/super", super_fn);
     engine.gc();
 }

src/script.rs

@@ -104,6 +104,9 @@ impl<E: Engine> Value<E> {
     }
     pub fn add_car(&mut self, car: Self) {
         match self {
+            Self::Null => {
+                *self = Self::RevArray(vec![car]);
+            }
             Self::RevArray(ref mut x) => {
                 x.push(car);
             }

tmp.scm

@@ -1,8 +1,10 @@
 (kbd/load-font "/home/user/.nix-profile/share/fonts/noto/NotoSans[wdth,wght].ttf")
 
-(kbd/defclass en ()
+(define state #f)
-  ((init) (kbd/set-user-data 'state 'lower))
+
-  ((state) (display (or (kbd/get-user-data 'state) 'lower)) (or (kbd/get-user-data 'state) 'lower))
+(kbd/defclass en (latin)
+  ((init) (set! state 'lower))
+  ((state) (or 'state 'lower))
   ((show-upper) (or (symbol=? (self state) 'upper) (symbol=? (self state) 'capslock)))
   ((show-lower) (symbol=? (self state) 'lower))
   ((show-symbols) (symbol=? (self state) 'symbols))
@@ -87,5 +89,4 @@
   ; signals
 
   ((kbd/width-changed)
-   (display "a !!!")
    (kbd/set-layout (self kbd-layout))))