Added Rust support to the Fun core. (0.38.0)

src/vm/rust/hello.c

@@ -0,0 +1,27 @@
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-01-27
+ */
+ 
+ /**
+ * Rust FFI demo opcode: OP_RUST_HELLO
+ * When executed, it pushes a hello string returned by Rust onto the VM stack.
+ */
+
+case OP_RUST_HELLO: {
+#ifdef FUN_WITH_RUST
+    const char *s = fun_rust_get_string();
+    if (!s) s = "";
+    push_value(vm, make_string(s));
+#else
+    vm_raise_error(vm, "RUST_HELLO requires FUN_WITH_RUST=ON at build time");
+    push_value(vm, make_nil());
+#endif
+    break;
+}