feat: copy `.erg`

src/copy.rs

@@ -0,0 +1,38 @@
+use std::path::Path;
+use std::fs::{copy, read_dir, create_dir_all};
+
+use erg_common::env::{erg_path, python_site_packages};
+
+fn copy_dir(from: impl AsRef<Path>, to: impl AsRef<Path>) -> std::io::Result<()> {
+    let from = from.as_ref();
+    let to = to.as_ref();
+    if !from.exists() {
+        return Ok(());
+    }
+    if !to.exists() {
+        create_dir_all(to)?;
+    }
+    for entry in read_dir(from)? {
+        let entry = entry?;
+        if entry.file_type()?.is_dir() {
+            copy_dir(entry.path(), to.join(entry.file_name()))?;
+        } else {
+            copy(entry.path(), to.join(entry.file_name()))?;
+        }
+    }
+    Ok(())
+}
+
+#[allow(unused)]
+pub(crate) fn copy_dot_erg() {
+    if erg_path().exists() {
+        return;
+    }
+    for site_packages in python_site_packages() {
+        if site_packages.join(".erg").exists() {
+            println!("Copying site-package/.erg to {}", erg_path().display());
+            copy_dir(site_packages.join(".erg"), erg_path())
+                .expect("Failed to copy .erg");
+        }
+    }
+}

src/lib.rs

@@ -1,5 +1,6 @@
 mod analyze;
 mod config;
 mod handle_err;
+mod copy;
 
 pub use analyze::PythonAnalyzer;

src/main.rs

@@ -1,13 +1,17 @@
 mod analyze;
 mod config;
 mod handle_err;
+mod copy;
 
 use analyze::{PythonAnalyzer, SimplePythonParser};
 use els::Server;
 use erg_common::config::ErgMode;
 use erg_common::spawn::exec_new_thread;
 
+use crate::copy::copy_dot_erg;
+
 fn run() {
+    copy_dot_erg();
     let cfg = config::parse_args();
     if cfg.mode == ErgMode::LanguageServer {
         let mut lang_server = Server::<PythonAnalyzer, SimplePythonParser>::new(cfg, None);