1 files changed, 38 insertions, 36 deletions

diff --git a/src/extension_loader.zig b/src/extension_loader.zig
index 0ab8091..87eb609 100644
--- a/src/extension_loader.zig
+++ b/src/extension_loader.zig
@@ -6,13 +6,13 @@
 //!
 //!   Extensions (full-featured; call `panto.ext.register_tool` from a script
 //!   that may register many tools):
-//!     1. `$PANTO_HOME/agent/extensions/`                          ("base")
+//!     1. `<data home>/agent/extensions/`                          ("base")
 //!     2. `${XDG_CONFIG_HOME:-$HOME/.config}/panto/extensions/`    ("user")
 //!     3. `./.panto/extensions/`                                   ("project")
 //!
 //!   Tools (ergonomic single-tool form; the script returns one table
 //!   shaped like the argument to `panto.ext.register_tool`):
-//!     1. `$PANTO_HOME/agent/tools/`                               ("base")
+//!     1. `<data home>/agent/tools/`                               ("base")
 //!     2. `${XDG_CONFIG_HOME:-$HOME/.config}/panto/tools/`         ("user")
 //!     3. `./.panto/tools/`                                        ("project")
 //!
@@ -124,7 +124,7 @@ pub const Kind = enum {
 ///
 /// `base_agent_dir`, when non-null, is the path under which embedded
 /// base tools/extensions have been staged — typically
-/// `$PANTO_HOME/agent/`. Pass `null` to skip the base layer entirely
+/// `<data home>/agent/`. Pass `null` to skip the base layer entirely
 /// (mostly useful for tests).
 ///
 /// `environ_map` is consulted for `HOME` and `XDG_CONFIG_HOME`. The
@@ -372,16 +372,19 @@ fn classifyFile(
     if (!std.mem.endsWith(u8, entry_name, ".lua")) return null;
     const base = entry_name[0 .. entry_name.len - ".lua".len];
     if (base.len == 0) return null;
+    if (base[0] == '_') return null;
 
     const script_path = try std.fs.path.join(allocator, &.{ dir_path, entry_name });
     errdefer allocator.free(script_path);
     const name = try allocator.dupe(u8, base);
     errdefer allocator.free(name);
+    const package_root = try allocator.dupe(u8, dir_path);
+    errdefer allocator.free(package_root);
 
     return Found{
         .name = name,
         .script_path = script_path,
-        .package_root = null,
+        .package_root = package_root,
         .source = source,
         .kind = kind,
     };
@@ -445,44 +448,42 @@ const ShadowKeyCtx = struct {
 };
 
 fn applyShadowing(allocator: Allocator, list: *std.array_list.Managed(Found)) !void {
-    var latest: std.HashMap(ShadowKey, usize, ShadowKeyCtx, std.hash_map.default_max_load_percentage) = .init(allocator);
+    const keep = try allocator.alloc(bool, list.items.len);
+    defer allocator.free(keep);
+    @memset(keep, false);
 
-    for (list.items, 0..) |f, i| {
-        try latest.put(.{ .kind = f.kind, .name = f.name }, i);
-    }
+    {
+        var latest: std.HashMap(ShadowKey, usize, ShadowKeyCtx, std.hash_map.default_max_load_percentage) = .init(allocator);
+        defer latest.deinit();
 
-    var keep: std.array_list.Managed(Found) = .init(allocator);
-    var drop: std.array_list.Managed(Found) = .init(allocator);
-    errdefer {
-        latest.deinit();
-        for (keep.items) |*f| f.deinit(allocator);
-        keep.deinit();
-        for (drop.items) |*f| f.deinit(allocator);
-        drop.deinit();
+        for (list.items, 0..) |f, i| {
+            try latest.put(.{ .kind = f.kind, .name = f.name }, i);
+        }
+
+        for (list.items, 0..) |f, i| {
+            const winner = latest.get(.{ .kind = f.kind, .name = f.name }).?;
+            if (winner == i) {
+                keep[i] = true;
+            } else {
+                std.log.debug(
+                    "{s}: '{s}' from {s} shadowed by {s}",
+                    .{ f.kind.label(), f.name, f.source.label(), list.items[winner].source.label() },
+                );
+            }
+        }
     }
-    try keep.ensureTotalCapacity(list.items.len);
-    try drop.ensureTotalCapacity(list.items.len);
 
-    for (list.items, 0..) |f, i| {
-        const winner = latest.get(.{ .kind = f.kind, .name = f.name }).?;
-        if (winner == i) {
-            keep.appendAssumeCapacity(f);
+    var write: usize = 0;
+    for (list.items, keep) |f, k| {
+        if (k) {
+            list.items[write] = f;
+            write += 1;
         } else {
-            std.log.debug(
-                "{s}: '{s}' from {s} shadowed by {s}",
-                .{ f.kind.label(), f.name, f.source.label(), list.items[winner].source.label() },
-            );
-            drop.appendAssumeCapacity(f);
+            var dropped = f;
+            dropped.deinit(allocator);
         }
     }
-
-    latest.deinit();
-    for (drop.items) |*f| f.deinit(allocator);
-    drop.deinit();
-
-    list.clearRetainingCapacity();
-    list.appendSlice(keep.items) catch unreachable;
-    keep.deinit();
+    list.shrinkRetainingCapacity(write);
 }
 
 // ---------------------------------------------------------------------------
@@ -527,6 +528,7 @@ test "scanDir picks up single-file and directory-style extensions" {
     try makeDir(tmp.dir, "ext_root");
     try makeDir(tmp.dir, "ext_root/beta");
     try writeFile(tmp.dir, "ext_root/alpha.lua", "-- alpha\n");
+    try writeFile(tmp.dir, "ext_root/_helper.lua", "-- helper module\n");
     try writeFile(tmp.dir, "ext_root/beta/init.lua", "-- beta init\n");
     try writeFile(tmp.dir, "ext_root/beta/helper.lua", "-- helper\n");
     try writeFile(tmp.dir, "ext_root/.ignored.lua", "-- hidden\n");
@@ -552,7 +554,7 @@ test "scanDir picks up single-file and directory-style extensions" {
     }.lt);
 
     try testing.expectEqualStrings("alpha", list.items[0].name);
-    try testing.expect(list.items[0].package_root == null);
+    try testing.expect(list.items[0].package_root != null);
     try testing.expect(std.mem.endsWith(u8, list.items[0].script_path, "alpha.lua"));
 
     try testing.expectEqualStrings("beta", list.items[1].name);