Remove unused system library and simplify environment initialization

The `system.myc` file, containing macros and core utilities, has been
removed as its functionality is now handled by an embedded string. This
simplifies the build process and eliminates a file that was no longer
strictly necessary.

Additionally, the `with_cwd()` method on the `Environment` has been
removed. The environment now automatically adds the current working
directory and its `rtl` subdirectory to the search paths during
initialization. This streamlines the setup for file-based usage and
ensures standard search paths are always considered.

rtl/system.myc

@@ -1,19 +0,0 @@
-;; Myc System Library
-;; Standard macros and core utilities.
-
-(do
-  (macro while [cond body]
-    `((fn [] (if ~cond
-               (do ~body (again))
-             )))
-  )
-
-  ;; Creates a stateful cache (Series) from a stateless stream.
-  (macro cache [lookback type src]
-    `(do
-       (def data (series ~lookback ~type))
-       (pipe [~src] (fn [s] (do (push data s))))
-       data
-     )
-  )
-)

src/ast/environment.rs

@@ -19,7 +19,6 @@ use crate::ast::compiler::macros::{MacroEvaluator, MacroExpander, MacroRegistry}
 use crate::ast::compiler::optimizer::Optimizer;
 use crate::ast::compiler::specializer::{FunctionRegistry, MonoCache, Specializer};
 use crate::ast::compiler::tco::{ExecNode, TCO};
-use crate::ast::rtl;
 use crate::ast::rtl::intrinsics;
 use crate::ast::types::{
     Identity, NodeIdentity, Object, Purity, SourceLocation, StaticType, Value,
@@ -28,6 +27,9 @@ use crate::ast::types::{
 use crate::ast::diagnostics::{DiagnosticLevel, Diagnostics};
 pub type PipelineGenerator = Box<dyn FnMut() -> bool>;
 
+const SYSTEM_LIB_SOURCE: &str = include_str!("system.myc");
+const SYSTEM_LIB_PATH: &str = "<embedded>/system.myc";
+
 pub struct CompilationResult {
     pub ast: Option<TypedNode>,
     pub diagnostics: Diagnostics,
@@ -169,22 +171,18 @@ impl Environment {
             search_paths: Rc::new(RefCell::new(Vec::new())),
             loaded_modules: Rc::new(RefCell::new(HashSet::new())),
         };
-        env.register_stdlib();
+        crate::ast::rtl::register(&env);
-        env
-    }
 
-    /// Adds the current working directory to the global search paths.
+        // Automatically add standard search paths (CWD and CWD/rtl)
-    /// 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);
+            env.add_search_path(&cwd);
-            // Also add the rtl subdirectory if it exists
             let rtl_path = cwd.join("rtl");
             if rtl_path.exists() {
-                self.add_search_path(rtl_path);
+                env.add_search_path(rtl_path);
             }
         }
-        self
+
+        env
     }
 
     pub fn add_search_path(&self, path: impl AsRef<Path>) {
@@ -276,16 +274,7 @@ impl Environment {
         base_path: &Path,
         all_files: &mut Vec<(PathBuf, Node<UntypedKind>)>,
     ) -> Result<(), String> {
-        let mut directives = self.extract_use_directives(source);
+        let directives = self.extract_use_directives(source);
-
-        // Implicitly add #use system if it's not already there and we can resolve it.
-        // This is only done for the root script (when loaded_modules is empty) to avoid redundancy.
-        if !directives.contains(&"system".to_string())
-            && self.loaded_modules.borrow().is_empty()
-            && self.resolve_module_paths("system", base_path).is_ok()
-        {
-            directives.insert(0, "system".to_string());
-        }
 
         for module_path in directives {
             let abs_paths = self.resolve_module_paths(&module_path, base_path)?;
@@ -352,7 +341,23 @@ impl Environment {
     pub fn preload_dependencies(&self, source: &str, file_path: Option<&Path>) -> Result<(), String> {
         let base_path = file_path.and_then(|p| p.parent()).unwrap_or_else(|| Path::new("."));
         let mut files = Vec::new();
-        
+
+        // 1. Always load the embedded system library first as a virtual module
+        let system_path = PathBuf::from(SYSTEM_LIB_PATH);
+        if !self.loaded_modules.borrow().contains(&system_path) {
+            self.loaded_modules.borrow_mut().insert(system_path.clone());
+            let mut parser = Parser::new(SYSTEM_LIB_SOURCE);
+            let untyped_ast = parser.parse_expression();
+            if parser.diagnostics.has_errors() {
+                return Err(format!(
+                    "Failed to parse embedded system library:\n{}",
+                    parser.diagnostics.items[0].message
+                ));
+            }
+            files.push((system_path, untyped_ast));
+        }
+
+        // 2. Collect dependencies from the main source
         self.collect_dependencies(source, base_path, &mut files)?;
 
         // Pass 1: Discovery (Globals and Macros)
@@ -463,7 +468,7 @@ impl Environment {
         Some(checker.check(&wrapped_ast, &[], diagnostics))
     }
 
-    pub fn compile_untyped(&self, untyped_ast: Node<UntypedKind>) -> Result<TypedNode, String> {
+    fn compile_untyped(&self, untyped_ast: Node<UntypedKind>) -> Result<TypedNode, String> {
         let mut diagnostics = Diagnostics::new();
 
         let typed_ast_opt = self.compile_pipeline(untyped_ast, &mut diagnostics);
@@ -530,9 +535,6 @@ impl Environment {
         values.push(val);
     }
 
-    fn register_stdlib(&self) {
-        rtl::register(self);
-    }
 
     pub fn dump_ast(&self, source: &str) -> Result<String, String> {
         self.preload_dependencies(source, None)?;
@@ -542,6 +544,10 @@ impl Environment {
     }
 
     pub fn compile(&self, source: &str) -> CompilationResult {
+        if let Err(e) = self.preload_dependencies(source, None) {
+            return CompilationResult::error(format!("Dependency Error: {}", e));
+        }
+
         let mut parser = Parser::new(source);
         let untyped_ast = parser.parse_expression();
 

src/bin/ast.rs

@@ -42,7 +42,7 @@ struct Cli {
 
 fn main() {
     let cli = Cli::parse();
-    let mut env = Environment::new().with_cwd();
+    let mut env = Environment::new();
     env.optimization = !cli.no_opt;
 
     // Load libraries (Now just search paths)
@@ -74,11 +74,6 @@ fn main() {
     }
 
     if let Some(script_str) = cli.eval {
-        if let Err(e) = env.preload_dependencies(&script_str, None) {
-            eprintln!("❌ Error resolving dependencies: {}", e);
-            std::process::exit(1);
-        }
-
         if cli.dump {
             match env.dump_ast(&script_str) {
                 Ok(dump) => println!("{}", dump),
@@ -92,11 +87,6 @@ fn main() {
     } else if let Some(file_path) = cli.file {
         match fs::read_to_string(&file_path) {
             Ok(content) => {
-                if let Err(e) = env.preload_dependencies(&content, Some(&file_path)) {
-                    eprintln!("❌ Error resolving dependencies for {:?}:\n{}", file_path, e);
-                    std::process::exit(1);
-                }
-
                 if cli.dump {
                     match env.dump_ast(&content) {
                         Ok(dump) => println!("{}", dump),

src/integration_test.rs

@@ -578,7 +578,7 @@ mod tests {
 
     #[test]
     fn test_record_inlining_in_while_loop() {
-        let env_ast = Environment::new().with_cwd();
+        let env_ast = Environment::new();
         // Ensure that constants (like the config record) are inherited into inner lambda scopes (like the body of a while loop).
         let source = r#"
         (do
@@ -603,7 +603,7 @@ mod tests {
         );
 
         // The result of running it should obviously still be correct.
-        let env_run = Environment::new().with_cwd();
+        let env_run = Environment::new();
         let res = env_run.run_script(source).unwrap();
         assert_eq!(format!("{}", res), "10");
     }

src/main.rs

@@ -61,7 +61,7 @@ impl Default for CompilerApp {
             })
             .unwrap_or_default();
 
-        let env = Environment::new().with_cwd();
+        let env = Environment::new();
 
         Self {
             source_code: String::from(
@@ -96,14 +96,10 @@ impl CompilerApp {
         self.trace_logs.clear();
 
         // Reset environment for a fresh run
-        self.env = Environment::new().with_cwd();
+        self.env = Environment::new();
         self.env.optimization = true;
 
         let res = (|| -> Result<(myc::ast::types::Value, std::time::Duration), String> {
-            if let Err(e) = self.env.preload_dependencies(&self.source_code, self.current_example_path.as_deref()) {
-                return Err(format!("Dependency Error: {}", e));
-            }
-
             let start_run = std::time::Instant::now();
             let result = if self.debug_enabled {
                 let (res, logs) = self.env.run_debug(&self.source_code)?;
@@ -162,14 +158,9 @@ impl CompilerApp {
     }
 
     fn dump_ast(&mut self) {
-        self.env = Environment::new().with_cwd();
+        self.env = Environment::new();
         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()) {
-            self.output_log = format!("Dependency Error: {}", e);
-            return;
-        }
-
         match self.env.dump_ast(&self.source_code) {
             Ok(dump) => {
                 self.output_log = format!("--- BOUND AST DUMP ---\n\n{}", dump);

src/utils/tester.rs

@@ -27,7 +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().with_cwd(); // Fresh environment per test file
+        let mut env = Environment::new(); // Fresh environment per test file
         env.optimization = enabled;
         let path = entry.path();
         if path.extension().is_some_and(|ext| ext == "myc") {
@@ -39,15 +39,6 @@ pub fn run_functional_tests_with_optimization(enabled: bool) -> Vec<TestResult>
                 .map(|m| m.get(1).unwrap().as_str().trim().to_string());
 
             if let Some(expected) = expected_output {
-                if let Err(e) = env.preload_dependencies(&content, Some(&path)) {
-                    results.push(TestResult {
-                        name,
-                        success: false,
-                        message: format!("Dependency Error: {}", e),
-                    });
-                    continue;
-                }
-
                 match env.run_script(&content) {
                     Ok(val) => {
                         let val_str = format!("{}", val);
@@ -120,20 +111,8 @@ 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().with_cwd();
+        let env = Environment::new();
-        
+        let compiled_once = match env.compile(&content).into_result() {
-        if let Err(e) = initial_env.preload_dependencies(&content, Some(&path)) {
-            results.push(BenchmarkResult {
-                name,
-                median: Duration::ZERO,
-                baseline: None,
-                diff_pct: None,
-                status: format!("DEPENDENCY ERROR: {}", e),
-            });
-            continue;
-        }
-
-        let compiled_once = match initial_env.compile(&content).into_result() {
             Ok(c) => c,
             Err(e) => {
                 results.push(BenchmarkResult {
@@ -150,10 +129,7 @@ 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().with_cwd();
+                let env = Environment::new();
-                if let Err(e) = env.preload_dependencies(&content, Some(&path)) {
-                    return Err(format!("Dependency Error in measurement: {}", e));
-                }
                 
                 // Link once per sample
                 let linked = env.link(node.clone());