feat(mingling): add directory environment resources and setup

Add four new resource types for common directory paths and a
convenience setup struct that registers all of them at once.

1 files changed, 77 insertions, 0 deletions

diff --git a/mingling/src/res/dirs/temp_dir.rs b/mingling/src/res/dirs/temp_dir.rs
new file mode 100644
index 0000000..f4f0dca
--- /dev/null
+++ b/mingling/src/res/dirs/temp_dir.rs
@@ -0,0 +1,77 @@
+use std::{
+    env::temp_dir,
+    path::{Path, PathBuf},
+};
+
+/// A global resource that provides the system temporary directory path.
+///
+/// This struct wraps a `PathBuf` representing the platform's temporary directory
+/// (e.g., `/tmp` on Unix, `%TEMP%` on Windows).
+///
+/// Note that `std::env::temp_dir()` is infallible — it always returns a path,
+/// falling back to a platform-specific default (e.g., `/tmp` on Unix) if the
+/// environment variable is not set.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct ResTempDir {
+    tmp: PathBuf,
+}
+
+impl ResTempDir {
+    /// Creates a new `ResTempDir` by querying the OS for the system temporary directory.
+    ///
+    /// This method is infallible since `std::env::temp_dir()` always succeeds,
+    /// returning a platform-specific default when environment variables are unset.
+    pub fn new() -> Self {
+        Self { tmp: temp_dir() }
+    }
+}
+
+impl Default for ResTempDir {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl From<PathBuf> for ResTempDir {
+    fn from(path: PathBuf) -> Self {
+        Self { tmp: path }
+    }
+}
+
+impl From<&Path> for ResTempDir {
+    fn from(path: &Path) -> Self {
+        Self { tmp: path.to_path_buf() }
+    }
+}
+
+impl From<&PathBuf> for ResTempDir {
+    fn from(path: &PathBuf) -> Self {
+        Self { tmp: path.clone() }
+    }
+}
+
+impl From<ResTempDir> for PathBuf {
+    fn from(res: ResTempDir) -> Self {
+        res.tmp
+    }
+}
+
+impl AsRef<Path> for ResTempDir {
+    fn as_ref(&self) -> &Path {
+        self.tmp.as_path()
+    }
+}
+
+impl std::ops::Deref for ResTempDir {
+    type Target = PathBuf;
+
+    fn deref(&self) -> &Self::Target {
+        &self.tmp
+    }
+}
+
+impl std::ops::DerefMut for ResTempDir {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.tmp
+    }
+}