wow it works

src/dsl.rs

@@ -0,0 +1,69 @@
+use std::sync::Arc;
+use std::thread;
+
+// Обобщённое выражение: I -> Out
+pub trait Expr<I> {
+    type Out;
+    fn eval(&self, x: I) -> Self::Out;
+}
+
+// атомарная функция
+pub struct Function<I, O> {
+    pub f: fn(I) -> O,
+}
+
+impl<I, O> Expr<I> for Function<I, O> {
+    type Out = O;
+    fn eval(&self, x: I) -> O {
+        (self.f)(x)
+    }
+}
+
+// композиция g∘f
+pub struct Composition<F1, F2> {
+    pub first: F1,
+    pub second: F2,
+}
+
+impl<I, F1, F2> Expr<I> for Composition<F1, F2>
+where
+    F1: Expr<I>,
+    F2: Expr<F1::Out>,
+{
+    type Out = F2::Out;
+
+    fn eval(&self, x: I) -> Self::Out {
+        let mid = self.first.eval(x);
+        self.second.eval(mid)
+    }
+}
+
+// junction — две ветки параллельно
+pub struct Junction<F1, F2> {
+    pub left: Arc<F1>,
+    pub right: Arc<F2>,
+}
+
+impl<I, F1, F2> Expr<I> for Junction<F1, F2>
+where
+    I: Copy + Send + 'static,
+    F1: Expr<I> + Send + Sync + 'static,
+    F2: Expr<I> + Send + Sync + 'static,
+    F1::Out: Send + 'static,
+    F2::Out: Send + 'static,
+{
+    type Out = (F1::Out, F2::Out);
+
+    fn eval(&self, x: I) -> (F1::Out, F2::Out) {
+        let l = Arc::clone(&self.left);
+        let r = Arc::clone(&self.right);
+
+        let x1 = x;
+        let x2 = x;
+
+        let h1 = thread::spawn(move || l.eval(x1));
+        let h2 = thread::spawn(move || r.eval(x2));
+
+        (h1.join().unwrap(), h2.join().unwrap())
+    }
+}