Code enhancements.

src/module/resolvers/dummy.rs

@@ -0,0 +1,48 @@
+use crate::stdlib::boxed::Box;
+use crate::{Engine, EvalAltResult, Module, ModuleResolver, Position, Shared};
+
+/// Empty/disabled module resolution service that acts as a dummy.
+///
+/// # Example
+///
+/// ```
+/// use rhai::{Engine, Module};
+/// use rhai::module_resolvers::DummyModuleResolver;
+///
+/// let resolver = DummyModuleResolver::new();
+/// let mut engine = Engine::new();
+/// engine.set_module_resolver(resolver);
+/// ```
+#[derive(Debug, Copy, Eq, PartialEq, Clone, Default, Hash)]
+pub struct DummyModuleResolver;
+
+impl DummyModuleResolver {
+    /// Create a new [`DummyModuleResolver`].
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use rhai::{Engine, Module};
+    /// use rhai::module_resolvers::DummyModuleResolver;
+    ///
+    /// let resolver = DummyModuleResolver::new();
+    /// let mut engine = Engine::new();
+    /// engine.set_module_resolver(resolver);
+    /// ```
+    #[inline(always)]
+    pub fn new() -> Self {
+        Default::default()
+    }
+}
+
+impl ModuleResolver for DummyModuleResolver {
+    #[inline(always)]
+    fn resolve(
+        &self,
+        _: &Engine,
+        path: &str,
+        pos: Position,
+    ) -> Result<Shared<Module>, Box<EvalAltResult>> {
+        EvalAltResult::ErrorModuleNotFound(path.into(), pos).into()
+    }
+}