feat: Enhance #use directive for directories and cwd

The `#use` directive now supports referencing entire directories,
automatically including all `.myc` files within them. Additionally,
environments are now initialized with the current working directory as a
default search path, simplifying module resolution.

docs/dependency_management.md

@@ -20,20 +20,21 @@ We need a way to explicitly define dependencies *within* a Myc script, ensuring
 
 ## The Solution: `#use` Preprocessor Directives
 
-We introduce a preprocessor directive `#use` that is evaluated *before* the main parsing phase begins.
+We introduce a preprocessor directive `#use` that is evaluated *before* the main parsing phase begins. It can target either single files or entire directories.
 
 ### Syntax
 
 ```myc
 #use math->indicators
 #use utils
+#use mylib
 
 (do
   ;; Actual Myc code begins here
   (def my_var (indicators.calculate ...))
 )
 ```
-*(Here `math->indicators` resolves to `math/indicators.myc` and `utils` resolves to `utils.myc`)*
+*(Here `math->indicators` resolves to the file `math/indicators.myc`. `utils` resolves to `utils.myc`. If `mylib` is a directory instead of a file, it resolves to all `.myc` files within that directory.)*
 
 ### Implementation Plan
 
@@ -41,13 +42,15 @@ We introduce a preprocessor directive `#use` that is evaluated *before* the main
    The `Environment` will be extended with a `HashSet<PathBuf>` (e.g., `loaded_modules`) to keep track of canonical paths that have already been loaded, ensuring idempotency.
 
 2. **Pre-Parse Extraction:**
-   Before the AST `Parser` processes a script, a lightweight scraper will read the top lines of the file. It will extract all `#use` paths and stop as soon as it encounters a line that is not empty, not a comment (`;`), and not a `#use` directive.
+   Before the AST `Parser` processes a script, a lightweight scraper will read the top lines of the file. It will extract all `#use` paths and stop as soon as it encounters a line that is not empty, not a comment (`;` or `#`), and not a `#use` directive.
 
 3. **Recursive Resolution:**
-   - The scraper extracts the module path, replaces `->` with the OS-specific directory separator, and appends `.myc`.
-   - Paths are resolved relative to the file that declares the dependency.
+   - The scraper extracts the module path and replaces `->` with the OS-specific directory separator.
+   - It first checks if `<path>.myc` exists as a file. If it does, it resolves to that single file.
+   - If not, it checks if `<path>` is a directory. If so, it resolves to all `.myc` files inside that directory (sorted alphabetically).
+   - Paths are resolved relative to the file that declares the dependency, with a fallback to the global `--lib` search paths.
    - If a path is not in `loaded_modules`, it is added to the set.
-   - The file is read, and the extraction process runs recursively on its content.
+   - The files are read, and the extraction process runs recursively on their content.
    - This creates a flat list of all dependencies in a valid topological order.
 
 4. **Two-Pass Compilation:**

examples/sma.myc

@@ -1,10 +1,9 @@
-#use lib->sma
-;; Output: void
+#use rtl
 
 (do
   (def sma20 (SMA 20))
 
-  (def n 1000)
+  (def n 100)
   (while (> n 0)
     (do
       (print "val=" n " sma20=" (sma20 n))

src/ast/environment.rs

@@ -173,6 +173,15 @@ impl Environment {
         env
     }
 
+    /// Adds the current working directory to the global search paths.
+    /// This is a builder method to easily initialize an environment for file-based usage.
+    pub fn with_cwd(self) -> Self {
+        if let Ok(cwd) = std::env::current_dir() {
+            self.add_search_path(cwd);
+        }
+        self
+    }
+
     pub fn add_search_path(&self, path: impl AsRef<Path>) {
         self.search_paths.borrow_mut().push(path.as_ref().to_path_buf());
     }
@@ -215,27 +224,54 @@ impl Environment {
     }
 
     /// Resolves a #use module path relative to a base path, then falls back to search paths.
-    fn resolve_module_path(&self, module_path: &str, base_path: &Path) -> Result<PathBuf, String> {
+    /// Returns a list of all matching .myc files (single file, or all files in a directory).
+    fn resolve_module_paths(&self, module_path: &str, base_path: &Path) -> Result<Vec<PathBuf>, String> {
         let relative_path = module_path.replace("->", std::path::MAIN_SEPARATOR_STR);
         let file_name = format!("{}.myc", relative_path);
 
+        let check_path = |base: &Path| -> Option<Vec<PathBuf>> {
+            // Check for file first
+            let mut file_p = base.to_path_buf();
+            file_p.push(&file_name);
+            if file_p.is_file() && let Ok(canon) = file_p.canonicalize() {
+                return Some(vec![canon]);
+            }
+
+            // Check for directory
+            let mut dir_p = base.to_path_buf();
+            dir_p.push(&relative_path);
+            if dir_p.is_dir() {
+                let mut files = Vec::new();
+                if let Ok(entries) = std::fs::read_dir(&dir_p) {
+                    let mut valid_entries: Vec<_> = entries.filter_map(|e| e.ok()).collect();
+                    valid_entries.sort_by_key(|e| e.path());
+                    for entry in valid_entries {
+                        let p = entry.path();
+                        if p.is_file() && p.extension().is_some_and(|ext| ext == "myc") && let Ok(canon) = p.canonicalize() {
+                            files.push(canon);
+                        }
+                    }
+                }
+                if !files.is_empty() {
+                    return Some(files);
+                }
+            }
+            None
+        };
+
         // 1. Try relative to base_path
-        let mut path = base_path.to_path_buf();
-        path.push(&file_name);
-        if path.is_file() {
-            return path.canonicalize().map_err(|e| format!("IO Error: {}", e));
+        if let Some(paths) = check_path(base_path) {
+            return Ok(paths);
         }
 
         // 2. Try search paths
         for sp in self.search_paths.borrow().iter() {
-            let mut path = sp.clone();
-            path.push(&file_name);
-            if path.is_file() {
-                return path.canonicalize().map_err(|e| format!("IO Error: {}", e));
+            if let Some(paths) = check_path(sp) {
+                return Ok(paths);
             }
         }
 
-        Err(format!("Could not find module '{}' (looked for {})", module_path, file_name))
+        Err(format!("Could not find module or directory '{}'", module_path))
     }
 
     /// Recursively collects all dependencies starting from a given source string.
@@ -248,33 +284,35 @@ impl Environment {
         let directives = self.extract_use_directives(source);
 
         for module_path in directives {
-            let abs_path = self.resolve_module_path(&module_path, base_path)?;
+            let abs_paths = self.resolve_module_paths(&module_path, base_path)?;
 
-            if self.loaded_modules.borrow().contains(&abs_path) {
-                continue;
+            for abs_path in abs_paths {
+                if self.loaded_modules.borrow().contains(&abs_path) {
+                    continue;
+                }
+
+                self.loaded_modules.borrow_mut().insert(abs_path.clone());
+
+                let lib_source = std::fs::read_to_string(&abs_path)
+                    .map_err(|e| format!("Failed to read module {:?}: {}", abs_path, e))?;
+
+                // Pre-process dependencies of the library BEFORE adding it, ensuring topological order
+                let lib_base = abs_path.parent().unwrap_or(Path::new("."));
+                self.collect_dependencies(&lib_source, lib_base, all_files)?;
+
+                let mut parser = Parser::new(&lib_source);
+                let untyped_ast = parser.parse_expression();
+
+                if parser.diagnostics.has_errors() {
+                    return Err(format!(
+                        "Parser error in module {:?}:\n{}",
+                        abs_path,
+                        parser.diagnostics.items[0].message
+                    ));
+                }
+
+                all_files.push((abs_path, untyped_ast));
             }
-
-            self.loaded_modules.borrow_mut().insert(abs_path.clone());
-
-            let lib_source = std::fs::read_to_string(&abs_path)
-                .map_err(|e| format!("Failed to read module {:?}: {}", abs_path, e))?;
-
-            // Pre-process dependencies of the library BEFORE adding it, ensuring topological order
-            let lib_base = abs_path.parent().unwrap_or(Path::new("."));
-            self.collect_dependencies(&lib_source, lib_base, all_files)?;
-
-            let mut parser = Parser::new(&lib_source);
-            let untyped_ast = parser.parse_expression();
-
-            if parser.diagnostics.has_errors() {
-                return Err(format!(
-                    "Parser error in module {:?}:\n{}",
-                    abs_path,
-                    parser.diagnostics.items[0].message
-                ));
-            }
-
-            all_files.push((abs_path, untyped_ast));
         }
         Ok(())
     }

src/bin/ast.rs

@@ -42,7 +42,7 @@ struct Cli {
 
 fn main() {
     let cli = Cli::parse();
-    let mut env = Environment::new();
+    let mut env = Environment::new().with_cwd();
     env.optimization = !cli.no_opt;
 
     // Load libraries (Now just search paths)

src/main.rs

@@ -61,6 +61,8 @@ impl Default for CompilerApp {
             })
             .unwrap_or_default();
 
+        let env = Environment::new().with_cwd();
+
         Self {
             source_code: String::from(
                 r#"
@@ -81,7 +83,7 @@ impl Default for CompilerApp {
             trace_logs: Vec::new(),
             active_tab: AppTab::Output,
             debug_enabled: false,
-            env: Environment::new(),
+            env,
             is_first_frame: true,
             examples,
         }
@@ -94,7 +96,7 @@ impl CompilerApp {
         self.trace_logs.clear();
 
         // Reset environment for a fresh run
-        self.env = Environment::new();
+        self.env = Environment::new().with_cwd();
         self.env.optimization = true;
 
         let res = (|| -> Result<(myc::ast::types::Value, std::time::Duration), String> {
@@ -160,7 +162,7 @@ impl CompilerApp {
     }
 
     fn dump_ast(&mut self) {
-        self.env = Environment::new();
+        self.env = Environment::new().with_cwd();
         self.env.optimization = true; // Enable optimization for AST dump
         
         if let Err(e) = self.env.preload_dependencies(&self.source_code, self.current_example_path.as_deref()) {

src/utils/tester.rs

@@ -27,8 +27,7 @@ pub fn run_functional_tests_with_optimization(enabled: bool) -> Vec<TestResult>
     let output_re = Regex::new(r";; Output: (.*)").unwrap();
 
     for entry in entries.filter_map(|e| e.ok()) {
-        let mut env = Environment::new(); // Fresh environment per test file
-        env.add_search_path(".");
+        let mut env = Environment::new().with_cwd(); // Fresh environment per test file
         env.optimization = enabled;
         let path = entry.path();
         if path.extension().is_some_and(|ext| ext == "myc") {
@@ -121,8 +120,7 @@ pub fn run_benchmarks(update: bool, filter: Option<&str>) -> Vec<BenchmarkResult
             .unwrap_or(1);
 
         // Compile once for this file (symbols/types are compatible with all fresh environments)
-        let initial_env = Environment::new();
-        initial_env.add_search_path(".");
+        let initial_env = Environment::new().with_cwd();
         
         if let Err(e) = initial_env.preload_dependencies(&content, Some(&path)) {
             results.push(BenchmarkResult {
@@ -152,8 +150,7 @@ pub fn run_benchmarks(update: bool, filter: Option<&str>) -> Vec<BenchmarkResult
         // Helper to measure sum of VM execution times over N executions in one environment
         let measure_sum =
             |n: u32, node: &crate::ast::compiler::TypedNode| -> Result<Duration, String> {
-                let env = Environment::new();
-                env.add_search_path(".");
+                let env = Environment::new().with_cwd();
                 if let Err(e) = env.preload_dependencies(&content, Some(&path)) {
                     return Err(format!("Dependency Error in measurement: {}", e));
                 }