From 4d77dc88c6cb4fe8bf71fed6ad16b41c2de7f413 Mon Sep 17 00:00:00 2001
From: Shunsuke Shibayama <sbym1346@gmail.com>
Date: Sun, 10 Sep 2023 01:05:52 +0900
Subject: [PATCH] Update env.rs

---
 crates/erg_common/env.rs | 32 ++++++++++++++++++++------------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/crates/erg_common/env.rs b/crates/erg_common/env.rs
index 294d2cdd..5fab2049 100644
--- a/crates/erg_common/env.rs
+++ b/crates/erg_common/env.rs
@@ -7,11 +7,19 @@ use crate::python_util::get_sys_path;
 use crate::style::colors::*;
 use crate::style::RESET;
 
+fn fallback_erg_path() -> PathBuf {
+    #[allow(deprecated)]
+    std::env::home_dir().map_or(PathBuf::from(".erg"), |path| path.join(".erg"))
+}
+
 fn _erg_path() -> PathBuf {
     let path = var("ERG_PATH").unwrap_or_else(|_| env!("CARGO_ERG_PATH").to_string());
     PathBuf::from(path).canonicalize().unwrap_or_else(|_| {
-        eprintln!("{RED}[ERR] ERG_PATH not found{RESET}");
-        PathBuf::from(".")
+        let fallback = fallback_erg_path();
+        if !fallback.exists() {
+            eprintln!("{RED}[ERR] ERG_PATH not found{RESET}");
+        }
+        fallback
     })
 }
 fn _erg_std_path() -> PathBuf {
@@ -21,7 +29,7 @@ fn _erg_std_path() -> PathBuf {
         .canonicalize()
         .unwrap_or_else(|_| {
             eprintln!("{RED}[ERR] ERG_PATH/lib/std not found{RESET}");
-            PathBuf::from("lib/std/")
+            fallback_erg_path().join("lib/std")
         })
 }
 fn _erg_std_decl_path() -> PathBuf {
@@ -31,7 +39,7 @@ fn _erg_std_decl_path() -> PathBuf {
         .canonicalize()
         .unwrap_or_else(|_| {
             eprintln!("{RED}[ERR] ERG_PATH/lib/std.d not found {RESET}");
-            PathBuf::from("lib/std.d/")
+            fallback_erg_path().join("lib/std.d")
         })
 }
 fn _erg_pystd_path() -> PathBuf {
@@ -41,7 +49,7 @@ fn _erg_pystd_path() -> PathBuf {
         .canonicalize()
         .unwrap_or_else(|_| {
             eprintln!("{RED}[ERR] ERG_PATH/lib/pystd not found {RESET}");
-            PathBuf::from("lib/pystd/")
+            fallback_erg_path().join("lib/pystd")
         })
 }
 fn _erg_external_lib_path() -> PathBuf {
@@ -51,7 +59,7 @@ fn _erg_external_lib_path() -> PathBuf {
         .canonicalize()
         .unwrap_or_else(|_| {
             eprintln!("{RED}[ERR] ERG_PATH/lib/external not found {RESET}");
-            PathBuf::from("lib/external/")
+            fallback_erg_path().join("lib/external")
         })
 }
 fn _python_site_packages() -> impl Iterator<Item = PathBuf> {
@@ -62,7 +70,7 @@ fn _python_site_packages() -> impl Iterator<Item = PathBuf> {
         .map(|p| {
             p.canonicalize().unwrap_or_else(|_| {
                 eprintln!("{RED}[ERR] ERG_PATH/lib/external not found {RESET}");
-                PathBuf::from("lib/external/")
+                fallback_erg_path().join("lib/external")
             })
         })
 }
@@ -74,27 +82,27 @@ pub static ERG_PYSTD_PATH: OnceLock<PathBuf> = OnceLock::new();
 pub static ERG_EXTERNAL_LIB_PATH: OnceLock<PathBuf> = OnceLock::new();
 pub static PYTHON_SITE_PACKAGES: OnceLock<Vec<PathBuf>> = OnceLock::new();
 
-/// == `Path::new(".")` if ERG_PATH is not set
+/// == `Path::new("~/.erg")` if ERG_PATH is not set
 pub fn erg_path() -> &'static PathBuf {
     ERG_PATH.get_or_init(|| normalize_path(_erg_path())) // .with(|s| s.clone())
 }
 
-/// == `Path::new("lib/std")` if ERG_PATH is not set
+/// == `Path::new("~/.erg/lib/std")` if ERG_PATH is not set
 pub fn erg_std_path() -> &'static PathBuf {
     ERG_STD_PATH.get_or_init(|| normalize_path(_erg_std_path()))
 }
 
-/// == `Path::new("lib/std.d")` if ERG_PATH is not set
+/// == `Path::new("~/.erg/lib/std.d")` if ERG_PATH is not set
 pub fn erg_std_decl_path() -> &'static PathBuf {
     ERG_STD_DECL_PATH.get_or_init(|| normalize_path(_erg_std_decl_path()))
 }
 
-/// == `Path::new("lib/pystd")` if ERG_PATH is not set
+/// == `Path::new("~/.erg/lib/pystd")` if ERG_PATH is not set
 pub fn erg_pystd_path() -> &'static PathBuf {
     ERG_PYSTD_PATH.get_or_init(|| normalize_path(_erg_pystd_path()))
 }
 
-/// == `Path::new("lib/external")` if ERG_PATH is not set
+/// == `Path::new("~/.erg/lib/external")` if ERG_PATH is not set
 pub fn erg_py_external_lib_path() -> &'static PathBuf {
     ERG_EXTERNAL_LIB_PATH.get_or_init(|| normalize_path(_erg_external_lib_path()))
 }