new file: compiler.rs

new file:   primitives.rs
	new file:   store.rs
	new file:   support.rs

src/support.rs

@@ -0,0 +1,39 @@
+// Platform helpers to ease future no_std portability.
+// The crate currently depends on `std`, but concentrating platform-specific
+// pieces here makes migration simpler.
+
+#[cfg(feature = "std")]
+pub use std::sync::Arc;
+
+#[cfg(feature = "std")]
+pub fn run_parallel<L, R, OutL, OutR>(left: L, right: R) -> (OutL, OutR)
+where
+    L: FnOnce() -> OutL + Send + 'static,
+    R: FnOnce() -> OutR + Send + 'static,
+    OutL: Send + 'static,
+    OutR: Send + 'static,
+{
+    let h1 = std::thread::spawn(left);
+    let h2 = std::thread::spawn(right);
+    (h1.join().unwrap(), h2.join().unwrap())
+}
+
+#[cfg(not(feature = "std"))]
+mod no_std_support {
+    extern crate alloc;
+    pub use alloc::sync::Arc;
+
+    pub fn run_parallel<L, R, OutL, OutR>(left: L, right: R) -> (OutL, OutR)
+    where
+        L: FnOnce() -> OutL + Send + 'static,
+        R: FnOnce() -> OutR + Send + 'static,
+        OutL: Send + 'static,
+        OutR: Send + 'static,
+    {
+        // No threads available: fall back to sequential execution.
+        (left(), right())
+    }
+}
+
+#[cfg(not(feature = "std"))]
+pub use no_std_support::*;