Allow cross-loading of relative file paths in FileModuleResolver.

CHANGELOG.md

@@ -4,6 +4,18 @@ Rhai Release Notes
 Version 0.19.16
 ===============
 
+Breaking changes
+----------------
+
+* `ModuleResolver` trait methods take an additional parameter `source_path` that contains the path of the current environment. This is to facilitate loading other script files always from the current directory.
+* `FileModuleResolver` now resolves relative paths under the source path if there is no base path set.
+* `FileModuleResolver::base_path` now returns `Option<&str>` which is `None` if there is no base path set.
+
+New features
+------------
+
+* `FileModuleResolver` resolves relative paths under the parent path (i.e. the path holding the script that does the loading). This allows seamless cross-loading of scripts from a directory hierarchy instead of having all relative paths load from the current working directory.
+
 
 Version 0.19.15
 ===============

README.md

@@ -3,6 +3,7 @@ Rhai - Embedded Scripting for Rust
 
 ![GitHub last commit](https://img.shields.io/github/last-commit/rhaiscript/rhai?logo=github)
 [![Build Status](https://github.com/rhaiscript/rhai/workflows/Build/badge.svg)](https://github.com/rhaiscript/rhai/actions)
+[![stars](https://img.shields.io/github/stars/rhaiscript/rhai?logo=github)](https://github.com/rhaiscript/rhai)
 [![license](https://img.shields.io/crates/l/rhai)](https://github.com/license/rhaiscript/rhai)
 [![crates.io](https://img.shields.io/crates/v/rhai?logo=rust)](https://crates.io/crates/rhai/)
 [![crates.io](https://img.shields.io/crates/d/rhai?logo=rust)](https://crates.io/crates/rhai/)
@@ -35,7 +36,7 @@ Standard features
 * Built-in support for most common [data types](https://rhai.rs/book/language/values-and-types.html) including booleans, [integers](https://rhai.rs/book/language/numbers.html), [floating-point numbers](https://rhai.rs/book/language/numbers.html) (including [`Decimal`](https://crates.io/crates/rust_decimal)), [strings](https://rhai.rs/book/language/strings-chars.html), [Unicode characters](https://rhai.rs/book/language/strings-chars.html), [arrays](https://rhai.rs/book/language/arrays.html) and [object maps](https://rhai.rs/book/language/object-maps.html).
 * Easily [call a script-defined function](https://rhai.rs/book/engine/call-fn.html) from Rust.
 * Relatively little `unsafe` code (yes there are some for performance reasons).
-* Few dependencies (currently only [`smallvec`](https://crates.io/crates/smallvec), [`num-traits`](https://crates.io/crates/num-traits), [`ahash`](https://crates.io/crates/ahash)) and [`smartstring`](https://crates.io/crates/smartstring)).
+* Few dependencies - currently only [`smallvec`](https://crates.io/crates/smallvec), [`num-traits`](https://crates.io/crates/num-traits), [`ahash`](https://crates.io/crates/ahash) and [`smartstring`](https://crates.io/crates/smartstring).
 * Re-entrant scripting engine can be made `Send + Sync` (via the `sync` feature).
 * Compile once to [AST](https://rhai.rs/book/engine/compile.html) form for repeated evaluations.
 * Scripts are [optimized](https://rhai.rs/book/engine/optimize.html) (useful for template-based machine-generated scripts).

scripts/module.rhai

@@ -1,3 +1,3 @@
-import "scripts/loop";
+import "loop";
 
 print("Module test!");

src/bin/rhai-repl.rs

@@ -1,9 +1,12 @@
-use rhai::{Dynamic, Engine, EvalAltResult, Module, Scope, AST};
+use rhai::{
+    module_resolvers::FileModuleResolver, Dynamic, Engine, EvalAltResult, Module, Scope, AST,
+};
 
 use std::{
     env,
     fs::File,
     io::{stdin, stdout, Read, Write},
+    path::Path,
     process::exit,
 };
 
@@ -64,28 +67,39 @@ fn main() {
     #[cfg(not(feature = "no_module"))]
     #[cfg(not(feature = "no_std"))]
     {
-        // Set a file module resolver without caching
-        let mut resolver = rhai::module_resolvers::FileModuleResolver::new();
-        resolver.enable_cache(false);
-        engine.set_module_resolver(resolver);
-
         // Load init scripts
         let mut contents = String::new();
         let mut has_init_scripts = false;
 
         for filename in env::args().skip(1) {
+            let filename = match Path::new(&filename).canonicalize() {
+                Err(err) => {
+                    eprintln!("Error script file path: {}\n{}", filename, err);
+                    exit(1);
+                }
+                Ok(f) => f,
+            };
+
             contents.clear();
 
             let mut f = match File::open(&filename) {
                 Err(err) => {
-                    eprintln!("Error reading script file: {}\n{}", filename, err);
+                    eprintln!(
+                        "Error reading script file: {}\n{}",
+                        filename.to_string_lossy(),
+                        err
+                    );
                     exit(1);
                 }
                 Ok(f) => f,
             };
 
             if let Err(err) = f.read_to_string(&mut contents) {
-                println!("Error reading script file: {}\n{}", filename, err);
+                println!(
+                    "Error reading script file: {}\n{}",
+                    filename.to_string_lossy(),
+                    err
+                );
                 exit(1);
             }
 
@@ -93,10 +107,12 @@ fn main() {
                 .compile(&contents)
                 .map_err(|err| err.into())
                 .and_then(|mut ast| {
-                    ast.set_source(&filename);
+                    ast.set_source(filename.to_string_lossy());
                     Module::eval_ast_as_new(Default::default(), &ast, &engine)
                 }) {
                 Err(err) => {
+                    let filename = filename.to_string_lossy();
+
                     eprintln!("{:=<1$}", "", filename.len());
                     eprintln!("{}", filename);
                     eprintln!("{:=<1$}", "", filename.len());
@@ -112,7 +128,7 @@ fn main() {
 
             has_init_scripts = true;
 
-            println!("Script '{}' loaded.", filename);
+            println!("Script '{}' loaded.", filename.to_string_lossy());
         }
 
         if has_init_scripts {
@@ -124,17 +140,23 @@ fn main() {
     #[cfg(not(feature = "no_optimize"))]
     engine.set_optimization_level(rhai::OptimizationLevel::None);
 
+    // Set a file module resolver without caching
+    let mut resolver = FileModuleResolver::new();
+    resolver.enable_cache(false);
+    engine.set_module_resolver(resolver);
+
+    // Make Engine immutable
+    let engine = engine;
+
+    // Create scope
     let mut scope = Scope::new();
 
+    // REPL loop
     let mut input = String::new();
     let mut main_ast: AST = Default::default();
     let mut ast_u: AST = Default::default();
     let mut ast: AST = Default::default();
 
-    // Make Engine immutable
-    let engine = engine;
-
-    // REPL loop
     'main_loop: loop {
         print!("rhai-repl> ");
         stdout().flush().expect("couldn't flush stdout");

src/bin/rhai-run.rs

@@ -3,7 +3,7 @@ use rhai::{Engine, EvalAltResult, Position};
 #[cfg(not(feature = "no_optimize"))]
 use rhai::OptimizationLevel;
 
-use std::{env, fs::File, io::Read, process::exit};
+use std::{env, fs::File, io::Read, path::Path, process::exit};
 
 fn eprint_error(input: &str, mut err: EvalAltResult) {
     fn eprint_line(lines: &[&str], pos: Position, err_msg: &str) {
@@ -38,6 +38,14 @@ fn main() {
     let mut contents = String::new();
 
     for filename in env::args().skip(1) {
+        let filename = match Path::new(&filename).canonicalize() {
+            Err(err) => {
+                eprintln!("Error script file path: {}\n{}", filename, err);
+                exit(1);
+            }
+            Ok(f) => f,
+        };
+
         let mut engine = Engine::new();
 
         #[cfg(not(feature = "no_optimize"))]
@@ -45,7 +53,11 @@ fn main() {
 
         let mut f = match File::open(&filename) {
             Err(err) => {
-                eprintln!("Error reading script file: {}\n{}", filename, err);
+                eprintln!(
+                    "Error reading script file: {}\n{}",
+                    filename.to_string_lossy(),
+                    err
+                );
                 exit(1);
             }
             Ok(f) => f,
@@ -54,7 +66,11 @@ fn main() {
         contents.clear();
 
         if let Err(err) = f.read_to_string(&mut contents) {
-            eprintln!("Error reading script file: {}\n{}", filename, err);
+            eprintln!(
+                "Error reading script file: {}\n{}",
+                filename.to_string_lossy(),
+                err
+            );
             exit(1);
         }
 
@@ -65,7 +81,16 @@ fn main() {
             &contents[..]
         };
 
-        if let Err(err) = engine.consume(contents) {
+        if let Err(err) = engine
+            .compile(contents)
+            .map_err(|err| Box::new(err.into()) as Box<EvalAltResult>)
+            .and_then(|mut ast| {
+                ast.set_source(filename.to_string_lossy());
+                engine.consume_ast(&ast)
+            })
+        {
+            let filename = filename.to_string_lossy();
+
             eprintln!("{:=<1$}", "", filename.len());
             eprintln!("{}", filename);
             eprintln!("{:=<1$}", "", filename.len());

src/engine.rs

@@ -645,7 +645,7 @@ impl<'x, 'px> EvalContext<'_, 'x, 'px, '_, '_, '_, '_> {
         self.mods.iter()
     }
     /// _(INTERNALS)_ The current set of modules imported via `import` statements.
-    /// Available under the `internals` feature only.
+    /// Exported under the `internals` feature only.
     #[cfg(feature = "internals")]
     #[cfg(not(feature = "no_module"))]
     #[inline(always)]
@@ -658,7 +658,7 @@ impl<'x, 'px> EvalContext<'_, 'x, 'px, '_, '_, '_, '_> {
         self.lib.iter().cloned()
     }
     /// _(INTERNALS)_ The current set of namespaces containing definitions of all script-defined functions.
-    /// Available under the `internals` feature only.
+    /// Exported under the `internals` feature only.
     #[cfg(feature = "internals")]
     #[inline(always)]
     pub fn namespaces(&self) -> &[&Module] {
@@ -2433,19 +2433,22 @@ impl Engine {
                 {
                     use crate::ModuleResolver;
 
+                    let source = state.source.as_ref().map(|s| s.as_str());
                     let expr_pos = expr.position();
 
                     let module = state
                         .resolver
                         .as_ref()
-                        .and_then(|r| match r.resolve(self, &path, expr_pos) {
+                        .and_then(|r| match r.resolve(self, source, &path, expr_pos) {
                             Ok(m) => return Some(Ok(m)),
                             Err(err) => match *err {
                                 EvalAltResult::ErrorModuleNotFound(_, _) => None,
                                 _ => return Some(Err(err)),
                             },
                         })
-                        .unwrap_or_else(|| self.module_resolver.resolve(self, &path, expr_pos))?;
+                        .unwrap_or_else(|| {
+                            self.module_resolver.resolve(self, source, &path, expr_pos)
+                        })?;
 
                     if let Some(name) = export.as_ref().map(|x| x.name.clone()) {
                         if !module.is_indexed() {

src/engine_api.rs

@@ -317,10 +317,10 @@ impl Engine {
     /// ```
     #[cfg(not(feature = "no_object"))]
     #[inline(always)]
-    pub fn register_get<T: Variant + Clone, U: Variant + Clone>(
+    pub fn register_get<T: Variant + Clone, V: Variant + Clone>(
         &mut self,
         name: &str,
-        get_fn: impl Fn(&mut T) -> U + SendSync + 'static,
+        get_fn: impl Fn(&mut T) -> V + SendSync + 'static,
     ) -> &mut Self {
         use crate::engine::make_getter;
         self.register_fn(&make_getter(name), get_fn)
@@ -364,10 +364,10 @@ impl Engine {
     /// ```
     #[cfg(not(feature = "no_object"))]
     #[inline(always)]
-    pub fn register_get_result<T: Variant + Clone, U: Variant + Clone>(
+    pub fn register_get_result<T: Variant + Clone, V: Variant + Clone>(
         &mut self,
         name: &str,
-        get_fn: impl Fn(&mut T) -> Result<U, Box<EvalAltResult>> + SendSync + 'static,
+        get_fn: impl Fn(&mut T) -> Result<V, Box<EvalAltResult>> + SendSync + 'static,
     ) -> &mut Self {
         use crate::engine::make_getter;
         self.register_result_fn(&make_getter(name), get_fn)
@@ -410,10 +410,10 @@ impl Engine {
     /// ```
     #[cfg(not(feature = "no_object"))]
     #[inline(always)]
-    pub fn register_set<T: Variant + Clone, U: Variant + Clone>(
+    pub fn register_set<T: Variant + Clone, V: Variant + Clone>(
         &mut self,
         name: &str,
-        set_fn: impl Fn(&mut T, U) + SendSync + 'static,
+        set_fn: impl Fn(&mut T, V) + SendSync + 'static,
     ) -> &mut Self {
         use crate::engine::make_setter;
         self.register_fn(&make_setter(name), set_fn)
@@ -459,13 +459,13 @@ impl Engine {
     /// ```
     #[cfg(not(feature = "no_object"))]
     #[inline(always)]
-    pub fn register_set_result<T: Variant + Clone, U: Variant + Clone>(
+    pub fn register_set_result<T: Variant + Clone, V: Variant + Clone>(
         &mut self,
         name: &str,
-        set_fn: impl Fn(&mut T, U) -> Result<(), Box<EvalAltResult>> + SendSync + 'static,
+        set_fn: impl Fn(&mut T, V) -> Result<(), Box<EvalAltResult>> + SendSync + 'static,
     ) -> &mut Self {
         use crate::engine::make_setter;
-        self.register_result_fn(&make_setter(name), move |obj: &mut T, value: U| {
+        self.register_result_fn(&make_setter(name), move |obj: &mut T, value: V| {
             set_fn(obj, value)
         })
     }
@@ -510,11 +510,11 @@ impl Engine {
     /// ```
     #[cfg(not(feature = "no_object"))]
     #[inline(always)]
-    pub fn register_get_set<T: Variant + Clone, U: Variant + Clone>(
+    pub fn register_get_set<T: Variant + Clone, V: Variant + Clone>(
         &mut self,
         name: &str,
-        get_fn: impl Fn(&mut T) -> U + SendSync + 'static,
+        get_fn: impl Fn(&mut T) -> V + SendSync + 'static,
-        set_fn: impl Fn(&mut T, U) + SendSync + 'static,
+        set_fn: impl Fn(&mut T, V) + SendSync + 'static,
     ) -> &mut Self {
         self.register_get(name, get_fn).register_set(name, set_fn)
     }
@@ -562,9 +562,9 @@ impl Engine {
     /// ```
     #[cfg(not(feature = "no_index"))]
     #[inline(always)]
-    pub fn register_indexer_get<T: Variant + Clone, X: Variant + Clone, U: Variant + Clone>(
+    pub fn register_indexer_get<T: Variant + Clone, X: Variant + Clone, V: Variant + Clone>(
         &mut self,
-        get_fn: impl Fn(&mut T, X) -> U + SendSync + 'static,
+        get_fn: impl Fn(&mut T, X) -> V + SendSync + 'static,
     ) -> &mut Self {
         if TypeId::of::<T>() == TypeId::of::<Array>() {
             panic!("Cannot register indexer for arrays.");
@@ -631,10 +631,10 @@ impl Engine {
     pub fn register_indexer_get_result<
         T: Variant + Clone,
         X: Variant + Clone,
-        U: Variant + Clone,
+        V: Variant + Clone,
     >(
         &mut self,
-        get_fn: impl Fn(&mut T, X) -> Result<U, Box<EvalAltResult>> + SendSync + 'static,
+        get_fn: impl Fn(&mut T, X) -> Result<V, Box<EvalAltResult>> + SendSync + 'static,
     ) -> &mut Self {
         if TypeId::of::<T>() == TypeId::of::<Array>() {
             panic!("Cannot register indexer for arrays.");
@@ -696,9 +696,9 @@ impl Engine {
     /// ```
     #[cfg(not(feature = "no_index"))]
     #[inline(always)]
-    pub fn register_indexer_set<T: Variant + Clone, X: Variant + Clone, U: Variant + Clone>(
+    pub fn register_indexer_set<T: Variant + Clone, X: Variant + Clone, V: Variant + Clone>(
         &mut self,
-        set_fn: impl Fn(&mut T, X, U) + SendSync + 'static,
+        set_fn: impl Fn(&mut T, X, V) + SendSync + 'static,
     ) -> &mut Self {
         if TypeId::of::<T>() == TypeId::of::<Array>() {
             panic!("Cannot register indexer for arrays.");
@@ -766,10 +766,10 @@ impl Engine {
     pub fn register_indexer_set_result<
         T: Variant + Clone,
         X: Variant + Clone,
-        U: Variant + Clone,
+        V: Variant + Clone,
     >(
         &mut self,
-        set_fn: impl Fn(&mut T, X, U) -> Result<(), Box<EvalAltResult>> + SendSync + 'static,
+        set_fn: impl Fn(&mut T, X, V) -> Result<(), Box<EvalAltResult>> + SendSync + 'static,
     ) -> &mut Self {
         if TypeId::of::<T>() == TypeId::of::<Array>() {
             panic!("Cannot register indexer for arrays.");
@@ -787,7 +787,7 @@ impl Engine {
 
         self.register_result_fn(
             crate::engine::FN_IDX_SET,
-            move |obj: &mut T, index: X, value: U| set_fn(obj, index, value),
+            move |obj: &mut T, index: X, value: V| set_fn(obj, index, value),
         )
     }
     /// Short-hand for register both index getter and setter functions for a custom type with the [`Engine`].
@@ -834,10 +834,10 @@ impl Engine {
     /// ```
     #[cfg(not(feature = "no_index"))]
     #[inline(always)]
-    pub fn register_indexer_get_set<T: Variant + Clone, X: Variant + Clone, U: Variant + Clone>(
+    pub fn register_indexer_get_set<T: Variant + Clone, X: Variant + Clone, V: Variant + Clone>(
         &mut self,
-        get_fn: impl Fn(&mut T, X) -> U + SendSync + 'static,
+        get_fn: impl Fn(&mut T, X) -> V + SendSync + 'static,
-        set_fn: impl Fn(&mut T, X, U) -> () + SendSync + 'static,
+        set_fn: impl Fn(&mut T, X, V) -> () + SendSync + 'static,
     ) -> &mut Self {
         self.register_indexer_get(get_fn)
             .register_indexer_set(set_fn)
@@ -1070,7 +1070,7 @@ impl Engine {
 
                 match self
                     .module_resolver
-                    .resolve_ast(self, &path, Position::NONE)
+                    .resolve_ast(self, None, &path, Position::NONE)
                 {
                     Some(Ok(module_ast)) => {
                         collect_imports(&module_ast, &mut resolver, &mut imports)
@@ -1081,6 +1081,7 @@ impl Engine {
 
                 let module = shared_take_or_clone(self.module_resolver.resolve(
                     self,
+                    None,
                     &path,
                     Position::NONE,
                 )?);
@@ -1977,7 +1978,7 @@ impl Engine {
         crate::optimize::optimize_into_ast(self, scope, stmt.into_vec(), lib, optimization_level)
     }
     /// Generate a list of all registered functions.
-    /// Available under the `metadata` feature only.
+    /// Exported under the `metadata` feature only.
     ///
     /// Functions from the following sources are included, in order:
     /// 1) Functions registered into the global namespace

src/fn_native.rs

@@ -100,7 +100,7 @@ impl<'a> NativeCallContext<'a> {
         }
     }
     /// _(INTERNALS)_ Create a new [`NativeCallContext`].
-    /// Available under the `internals` feature only.
+    /// Exported under the `internals` feature only.
     #[cfg(feature = "internals")]
     #[cfg(not(feature = "no_module"))]
     #[inline(always)]
@@ -150,7 +150,7 @@ impl<'a> NativeCallContext<'a> {
         self.mods.iter().flat_map(|&m| m.iter_raw())
     }
     /// _(INTERNALS)_ The current set of modules imported via `import` statements.
-    /// Available under the `internals` feature only.
+    /// Exported under the `internals` feature only.
     #[cfg(feature = "internals")]
     #[cfg(not(feature = "no_module"))]
     #[inline(always)]
@@ -163,7 +163,7 @@ impl<'a> NativeCallContext<'a> {
         self.lib.iter().cloned()
     }
     /// _(INTERNALS)_ The current set of namespaces containing definitions of all script-defined functions.
-    /// Available under the `internals` feature only.
+    /// Exported under the `internals` feature only.
     #[cfg(feature = "internals")]
     #[inline(always)]
     pub fn namespaces(&self) -> &[&Module] {

src/fn_register.rs

@@ -60,15 +60,15 @@ pub trait RegisterNativeFunction<Args, Result> {
     /// Get the type ID's of this function's parameters.
     fn param_types() -> Box<[TypeId]>;
     /// Get the type names of this function's parameters.
-    /// Available under the `metadata` feature only.
+    /// Exported under the `metadata` feature only.
     #[cfg(feature = "metadata")]
     fn param_names() -> Box<[&'static str]>;
     /// Get the type ID of this function's return value.
-    /// Available under the `metadata` feature only.
+    /// Exported under the `metadata` feature only.
     #[cfg(feature = "metadata")]
     fn return_type() -> TypeId;
     /// Get the type name of this function's return value.
-    /// Available under the `metadata` feature only.
+    /// Exported under the `metadata` feature only.
     #[cfg(feature = "metadata")]
     fn return_type_name() -> &'static str;
 }

src/module/mod.rs

@@ -67,7 +67,7 @@ pub struct FuncInfo {
 
 impl FuncInfo {
     /// Generate a signature of the function.
-    /// Available under the `metadata` feature only.
+    /// Exported under the `metadata` feature only.
     #[cfg(feature = "metadata")]
     pub fn gen_signature(&self) -> String {
         let mut sig = format!("{}(", self.name);
@@ -363,7 +363,7 @@ impl Module {
     }
 
     /// Generate signatures for all the non-private functions in the [`Module`].
-    /// Available under the `metadata` feature only.
+    /// Exported under the `metadata` feature only.
     #[cfg(feature = "metadata")]
     #[inline(always)]
     pub fn gen_fn_signatures(&self) -> impl Iterator<Item = String> + '_ {
@@ -605,7 +605,7 @@ impl Module {
     }
 
     /// Update the metadata (parameter names/types and return type) of a registered function.
-    /// Available under the `metadata` feature only.
+    /// Exported under the `metadata` feature only.
     ///
     /// The [`u64`] hash is returned by the [`set_native_fn`][Module::set_native_fn] call.
     ///

src/module/resolvers/collection.rs

@@ -111,11 +111,12 @@ impl ModuleResolver for ModuleResolversCollection {
     fn resolve(
         &self,
         engine: &Engine,
+        source_path: Option<&str>,
         path: &str,
         pos: Position,
     ) -> Result<Shared<Module>, Box<EvalAltResult>> {
         for resolver in self.0.iter() {
-            match resolver.resolve(engine, path, pos) {
+            match resolver.resolve(engine, source_path, path, pos) {
                 Ok(module) => return Ok(module),
                 Err(err) => match *err {
                     EvalAltResult::ErrorModuleNotFound(_, _) => continue,

src/module/resolvers/dummy.rs

@@ -40,6 +40,7 @@ impl ModuleResolver for DummyModuleResolver {
     fn resolve(
         &self,
         _: &Engine,
+        _: Option<&str>,
         path: &str,
         pos: Position,
     ) -> Result<Shared<Module>, Box<EvalAltResult>> {

src/module/resolvers/file.rs

@@ -7,6 +7,8 @@ use crate::stdlib::{
 };
 use crate::{Engine, EvalAltResult, Module, ModuleResolver, Position, Shared};
 
+pub const RHAI_SCRIPT_EXTENSION: &str = "rhai";
+
 /// A [module][Module] resolution service that loads [module][Module] script files from the file system.
 ///
 /// ## Caching
@@ -39,7 +41,7 @@ use crate::{Engine, EvalAltResult, Module, ModuleResolver, Position, Shared};
 /// ```
 #[derive(Debug)]
 pub struct FileModuleResolver {
-    base_path: PathBuf,
+    base_path: Option<PathBuf>,
     extension: String,
     cache_enabled: bool,
 
@@ -52,11 +54,33 @@ pub struct FileModuleResolver {
 impl Default for FileModuleResolver {
     #[inline(always)]
     fn default() -> Self {
-        Self::new_with_path(PathBuf::default())
+        Self::new()
     }
 }
 
 impl FileModuleResolver {
+    /// Create a new [`FileModuleResolver`] with the current directory as base path.
+    ///
+    /// The default extension is `.rhai`.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use rhai::Engine;
+    /// use rhai::module_resolvers::FileModuleResolver;
+    ///
+    /// // Create a new 'FileModuleResolver' loading scripts from the current directory
+    /// // with file extension '.rhai' (the default).
+    /// let resolver = FileModuleResolver::new();
+    ///
+    /// let mut engine = Engine::new();
+    /// engine.set_module_resolver(resolver);
+    /// ```
+    #[inline(always)]
+    pub fn new() -> Self {
+        Self::new_with_extension(RHAI_SCRIPT_EXTENSION)
+    }
+
     /// Create a new [`FileModuleResolver`] with a specific base path.
     ///
     /// The default extension is `.rhai`.
@@ -76,7 +100,31 @@ impl FileModuleResolver {
     /// ```
     #[inline(always)]
     pub fn new_with_path(path: impl Into<PathBuf>) -> Self {
-        Self::new_with_path_and_extension(path, "rhai")
+        Self::new_with_path_and_extension(path, RHAI_SCRIPT_EXTENSION)
+    }
+
+    /// Create a new [`FileModuleResolver`] with a file extension.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// use rhai::Engine;
+    /// use rhai::module_resolvers::FileModuleResolver;
+    ///
+    /// // Create a new 'FileModuleResolver' loading scripts with file extension '.rhai' (the default).
+    /// let resolver = FileModuleResolver::new_with_extension("rhai");
+    ///
+    /// let mut engine = Engine::new();
+    /// engine.set_module_resolver(resolver);
+    /// ```
+    #[inline(always)]
+    pub fn new_with_extension(extension: impl Into<String>) -> Self {
+        Self {
+            base_path: None,
+            extension: extension.into(),
+            cache_enabled: true,
+            cache: Default::default(),
+        }
     }
 
     /// Create a new [`FileModuleResolver`] with a specific base path and file extension.
@@ -100,44 +148,22 @@ impl FileModuleResolver {
         extension: impl Into<String>,
     ) -> Self {
         Self {
-            base_path: path.into(),
+            base_path: Some(path.into()),
             extension: extension.into(),
             cache_enabled: true,
             cache: Default::default(),
         }
     }
 
-    /// Create a new [`FileModuleResolver`] with the current directory as base path.
-    ///
-    /// The default extension is `.rhai`.
-    ///
-    /// # Example
-    ///
-    /// ```
-    /// use rhai::Engine;
-    /// use rhai::module_resolvers::FileModuleResolver;
-    ///
-    /// // Create a new 'FileModuleResolver' loading scripts from the current directory
-    /// // with file extension '.rhai' (the default).
-    /// let resolver = FileModuleResolver::new();
-    ///
-    /// let mut engine = Engine::new();
-    /// engine.set_module_resolver(resolver);
-    /// ```
-    #[inline(always)]
-    pub fn new() -> Self {
-        Default::default()
-    }
-
     /// Get the base path for script files.
     #[inline(always)]
-    pub fn base_path(&self) -> &Path {
+    pub fn base_path(&self) -> Option<&Path> {
-        self.base_path.as_ref()
+        self.base_path.as_ref().map(PathBuf::as_ref)
     }
     /// Set the base path for script files.
     #[inline(always)]
     pub fn set_base_path(&mut self, path: impl Into<PathBuf>) -> &mut Self {
-        self.base_path = path.into();
+        self.base_path = Some(path.into());
         self
     }
 
@@ -168,12 +194,12 @@ impl FileModuleResolver {
 
     /// Is a particular path cached?
     #[inline(always)]
-    pub fn is_cached(&self, path: &str) -> bool {
+    pub fn is_cached(&self, path: &str, source_path: Option<&str>) -> bool {
         if !self.cache_enabled {
             return false;
         }
 
-        let file_path = self.get_file_path(path);
+        let file_path = self.get_file_path(path, source_path);
 
         #[cfg(not(feature = "sync"))]
         return self.cache.borrow_mut().contains_key(&file_path);
@@ -192,8 +218,12 @@ impl FileModuleResolver {
     ///
     /// The next time this path is resolved, the script file will be loaded once again.
     #[inline(always)]
-    pub fn clear_cache_for_path(&mut self, path: &str) -> Option<Shared<Module>> {
+    pub fn clear_cache_for_path(
-        let file_path = self.get_file_path(path);
+        &mut self,
+        path: &str,
+        source_path: Option<&str>,
+    ) -> Option<Shared<Module>> {
+        let file_path = self.get_file_path(path, source_path);
 
         #[cfg(not(feature = "sync"))]
         return self
@@ -210,9 +240,22 @@ impl FileModuleResolver {
             .map(|(_, v)| v);
     }
     /// Construct a full file path.
-    fn get_file_path(&self, path: &str) -> PathBuf {
+    fn get_file_path(&self, path: &str, source_path: Option<&str>) -> PathBuf {
-        let mut file_path = self.base_path.clone();
+        let path = Path::new(path);
+
+        let mut file_path;
+
+        if path.is_relative() {
+            file_path = self
+                .base_path
+                .clone()
+                .or_else(|| source_path.map(|p| p.into()))
+                .unwrap_or_default();
             file_path.push(path);
+        } else {
+            file_path = path.into();
+        }
+
         file_path.set_extension(&self.extension); // Force extension
         file_path
     }
@@ -222,11 +265,16 @@ impl ModuleResolver for FileModuleResolver {
     fn resolve(
         &self,
         engine: &Engine,
+        source_path: Option<&str>,
         path: &str,
         pos: Position,
     ) -> Result<Shared<Module>, Box<EvalAltResult>> {
+        // Load relative paths from source if there is no base path specified
+        let source_path =
+            source_path.and_then(|p| Path::new(p).parent().map(|p| p.to_string_lossy()));
+
         // Construct the script file path
-        let file_path = self.get_file_path(path);
+        let file_path = self.get_file_path(path, source_path.as_ref().map(|p| p.as_ref()));
 
         // See if it is cached
         if self.is_cache_enabled() {
@@ -276,11 +324,12 @@ impl ModuleResolver for FileModuleResolver {
     fn resolve_ast(
         &self,
         engine: &Engine,
+        source_path: Option<&str>,
         path: &str,
         pos: Position,
     ) -> Option<Result<crate::AST, Box<EvalAltResult>>> {
         // Construct the script file path
-        let file_path = self.get_file_path(path);
+        let file_path = self.get_file_path(path, source_path);
 
         // Load the script file and compile it
         match engine.compile_file(file_path).map_err(|err| match *err {

src/module/resolvers/mod.rs

@@ -25,6 +25,7 @@ pub trait ModuleResolver: SendSync {
     fn resolve(
         &self,
         engine: &Engine,
+        source_path: Option<&str>,
         path: &str,
         pos: Position,
     ) -> Result<Shared<Module>, Box<EvalAltResult>>;
@@ -42,6 +43,7 @@ pub trait ModuleResolver: SendSync {
     fn resolve_ast(
         &self,
         engine: &Engine,
+        source_path: Option<&str>,
         path: &str,
         pos: Position,
     ) -> Option<Result<AST, Box<EvalAltResult>>> {

src/module/resolvers/stat.rs

@@ -115,6 +115,7 @@ impl ModuleResolver for StaticModuleResolver {
     fn resolve(
         &self,
         _: &Engine,
+        _: Option<&str>,
         path: &str,
         pos: Position,
     ) -> Result<Shared<Module>, Box<EvalAltResult>> {

src/serde/metadata.rs

@@ -212,7 +212,7 @@ impl From<&crate::Module> for ModuleMetadata {
 impl Engine {
     /// _(METADATA)_ Generate a list of all functions (including those defined in an
     /// [`AST`][crate::AST]) in JSON format.
-    /// Available under the `metadata` feature only.
+    /// Exported under the `metadata` feature only.
     ///
     /// Functions from the following sources are included:
     /// 1) Functions defined in an [`AST`][crate::AST]
@@ -221,9 +221,10 @@ impl Engine {
     /// 4) Functions in global modules (optional)
     pub fn gen_fn_metadata_with_ast_to_json(
         &self,
-        _ast: &AST,
+        ast: &AST,
         include_global: bool,
     ) -> serde_json::Result<String> {
+        let _ast = ast;
         let mut global: ModuleMetadata = Default::default();
 
         if include_global {