Doc fixes

Try to use the term "global singleton" consistently. That's also the
term we use in the language reference.

api/sixtyfps-cpp/include/sixtyfps_interpreter.h

@@ -710,10 +710,10 @@ public:
                 new F(std::move(callback)), [](void *data) { delete reinterpret_cast<F *>(data); });
     }
 
-    /// Set the value for a property within an exported global
+    /// Set the value for a property within an exported global singleton.
     ///
-    /// For example, if the main file has an exported global `TheGlobal` with a `property <int> hello`,
-    /// we can set this property
+    /// For example, if the main file has an exported global `TheGlobal` with a `property <int>
+    /// hello`, we can set this property
     /// ```
     /// instance->set_global_property("TheGlobal", "hello", 42);
     /// ```
@@ -729,7 +729,7 @@ public:
                 inner(), sixtyfps::private_api::string_to_slice(global),
                 sixtyfps::private_api::string_to_slice(prop_name), &value.inner);
     }
-    /// Returns the value behind a property in an exported global.
+    /// Returns the value behind a property in an exported global singleton.
     std::optional<Value> get_global_property(std::string_view global,
                                              std::string_view prop_name) const
     {
@@ -744,7 +744,7 @@ public:
         }
     }
 
-    /// Like `set_callback()` but on a callback in the specified exported global
+    /// Like `set_callback()` but on a callback in the specified exported global singleton.
     ///
     /// Example: imagine the .60 file contains the given global:
     /// ```60
@@ -776,7 +776,7 @@ public:
     }
 
     // FIXME! Slice in public API?  Should be std::span (c++20) or we need to improve the Slice API
-    /// Invoke the specified callback declared in an exported global
+    /// Invoke the specified callback declared in an exported global singleton
     std::optional<Value> invoke_global_callback(std::string_view global,
                                                 std::string_view callback_name,
                                                 Slice<Value> args) const

api/sixtyfps-rs/docs.rs

@@ -158,7 +158,7 @@ pub mod generated_code {
             unimplemented!();
         }
 
-        /// This function provides access to instances of global structures exported in `.60`.
+        /// This function provides access to instances of global singletons exported in `.60`.
         fn global<'a, T: Global<'a, Self>>(&'a self) -> T {
             unimplemented!()
         }

api/sixtyfps-rs/lib.rs

@@ -421,13 +421,13 @@ pub fn invoke_from_event_loop(func: impl FnOnce() + Send + 'static) {
     sixtyfps_rendering_backend_default::backend().post_event(Box::new(func))
 }
 
-/// This trait is used to obtain references to global structures exported in `.60`
+/// This trait is used to obtain references to global singletons exported in `.60`
 /// markup. Alternatively, you can use [`ComponentHandle::global`] to obtain access.
 ///
-/// This trait is implemented by the compiler for each global that's exported.
+/// This trait is implemented by the compiler for each global singleton that's exported.
 ///
 /// # Example
-/// The following example of `.60` markup defines a global called `Palette`, exports
+/// The following example of `.60` markup defines a global singleton called `Palette`, exports
 /// it and modifies it from Rust code:
 /// ```rust
 /// sixtyfps::sixtyfps!{
@@ -448,11 +448,11 @@ pub fn invoke_from_event_loop(func: impl FnOnce() + Send + 'static) {
 /// let app = App::new();
 /// app.global::<Palette>().set_background_color(sixtyfps::Color::from_rgb_u8(0, 0, 0));
 ///
-/// // alternate way to access the global:
+/// // alternate way to access the global singleton:
 /// Palette::get(&app).set_foreground_color(sixtyfps::Color::from_rgb_u8(255, 255, 255));
 /// ```
 ///
-/// See also the [language reference for globals](docs/langref/index.html#global-singletons) for more information.
+/// See also the [language reference for global singletons](docs/langref/index.html#global-singletons) for more information.
 pub trait Global<'a, Component> {
     /// Returns a reference that's tied to the life time of the provided component.
     fn get(component: &'a Component) -> Self;
@@ -498,7 +498,7 @@ pub trait ComponentHandle {
     /// and [`Self::hide`].
     fn run(&self);
 
-    /// This function provides access to instances of global structures exported in `.60`.
+    /// This function provides access to instances of global singletons exported in `.60`.
     /// See [`Global`] for an example how to export and access globals from `.60` markup.
     fn global<'a, T: Global<'a, Self>>(&'a self) -> T
     where

sixtyfps_runtime/interpreter/api.rs

@@ -788,9 +788,9 @@ impl ComponentInstance {
             .map_err(|()| CallCallbackError::NoSuchCallback)
     }
 
-    /// Return the value for a property within an exported global used by this component.
+    /// Return the value for a property within an exported global singleton used by this component.
     ///
-    /// The `global` parameter is the exported name of the global. The `property` argument
+    /// The `global` parameter is the exported name of the global singleton. The `property` argument
     /// is the name of the property
     ///
     /// ## Examples
@@ -827,7 +827,7 @@ impl ComponentInstance {
             .map_err(|()| GetPropertyError::NoSuchProperty)
     }
 
-    /// Set the value for a property within an exported global used by this component.
+    /// Set the value for a property within an exported global singleton used by this component.
     pub fn set_global_property(
         &self,
         global: &str,
@@ -843,7 +843,7 @@ impl ComponentInstance {
             .set_property(&normalize_identifier(property), value)
     }
 
-    /// Set a handler for the callback in the exported global. A callback with that
+    /// Set a handler for the callback in the exported global singleton. A callback with that
     /// name must be defined in the specified global and the global must be exported from the
     /// main document otherwise an error will be returned.
     ///
@@ -892,7 +892,7 @@ impl ComponentInstance {
             .map_err(|()| SetCallbackError::NoSuchCallback)
     }
 
-    /// Call the given callback within a global with the arguments
+    /// Call the given callback within a global singleton with the arguments
     ///
     /// ## Examples
     /// See the documentation of [`Self::set_global_callback`] for an example