From 4362245debe71b7fd03e7f655c1999627b2edbe0 Mon Sep 17 00:00:00 2001
From: "Shane F. Carr" <shane@unicode.org>
Date: Tue, 25 Aug 2020 16:10:17 -0500
Subject: [PATCH] Review feedback.

---
 .../cldr-json-data-provider/src/reader.rs     |  8 ++---
 .../cldr-json-data-provider/src/support.rs    | 32 +++++++++----------
 .../src/transform/mod.rs                      |  9 +++---
 3 files changed, 23 insertions(+), 26 deletions(-)

diff --git a/components/cldr-json-data-provider/src/reader.rs b/components/cldr-json-data-provider/src/reader.rs
index 5301dca7a67..2fe9db04e51 100644
--- a/components/cldr-json-data-provider/src/reader.rs
+++ b/components/cldr-json-data-provider/src/reader.rs
@@ -5,9 +5,7 @@ use std::path::PathBuf;
 
 /// Helper function to open a file and return failures as a crate error.
 pub fn open_reader(path: PathBuf) -> Result<BufReader<File>, Error> {
-    let file = match File::open(&path) {
-        Ok(file) => file,
-        Err(err) => return Err(Error::IoError(err, path)),
-    };
-    Ok(BufReader::new(file))
+    File::open(&path)
+        .map(BufReader::new)
+        .map_err(|e| Error::IoError(e, path))
 }
diff --git a/components/cldr-json-data-provider/src/support.rs b/components/cldr-json-data-provider/src/support.rs
index 57ecc4fb13b..f047251925c 100644
--- a/components/cldr-json-data-provider/src/support.rs
+++ b/components/cldr-json-data-provider/src/support.rs
@@ -12,6 +12,14 @@ pub(crate) struct LazyCldrProvider<T> {
     src: RwLock<Option<T>>,
 }
 
+impl<T> Default for LazyCldrProvider<T> {
+    fn default() -> Self {
+        LazyCldrProvider {
+            src: RwLock::new(None),
+        }
+    }
+}
+
 fn map_poison<E>(_err: E) -> DataError {
     // Can't return the PoisonError directly because it has lifetime parameters.
     DataError::new_resc_error(crate::error::Error::PoisonError)
@@ -23,12 +31,6 @@ where
     T: DataProvider<'d> + DataKeySupport + DataEntryCollection + TryFrom<&'b CldrPaths>,
     <T as TryFrom<&'b CldrPaths>>::Error: 'static + std::error::Error,
 {
-    pub fn new() -> Self {
-        Self {
-            src: RwLock::new(None),
-        }
-    }
-
     /// Call T::load, initializing T if necessary.
     pub fn try_load(
         &self,
@@ -45,11 +47,10 @@ where
         if src.is_none() {
             src.replace(T::try_from(cldr_paths).map_err(DataError::new_resc_error)?);
         }
-        // The RwLock is guaranteed to be populated at this point.
-        if let Some(data_provider) = src.as_ref() {
-            return data_provider.load(req).map(Some);
-        }
-        unreachable!();
+        let data_provider = src
+            .as_ref()
+            .expect("The RwLock must be populated at this point.");
+        data_provider.load(req).map(Some)
     }
 
     /// Call T::iter_for_key, initializing T if necessary.
@@ -68,10 +69,9 @@ where
         if src.is_none() {
             src.replace(T::try_from(cldr_paths).map_err(DataError::new_resc_error)?);
         }
-        // The RwLock is guaranteed to be populated at this point.
-        if let Some(data_provider) = src.as_ref() {
-            return data_provider.iter_for_key(data_key).map(Some);
-        }
-        unreachable!();
+        let data_provider = src
+            .as_ref()
+            .expect("The RwLock must be populated at this point.");
+        data_provider.iter_for_key(data_key).map(Some)
     }
 }
diff --git a/components/cldr-json-data-provider/src/transform/mod.rs b/components/cldr-json-data-provider/src/transform/mod.rs
index 1d70642ba33..c14fbafc95a 100644
--- a/components/cldr-json-data-provider/src/transform/mod.rs
+++ b/components/cldr-json-data-provider/src/transform/mod.rs
@@ -16,17 +16,16 @@ impl<'a, 'd> CldrJsonDataProvider<'a, 'd> {
     pub fn new(cldr_paths: &'a CldrPaths) -> Self {
         CldrJsonDataProvider {
             cldr_paths,
-            plurals: LazyCldrProvider::new(),
+            plurals: Default::default(),
         }
     }
 }
 
 impl<'a, 'd> DataProvider<'d> for CldrJsonDataProvider<'a, 'd> {
     fn load(&self, req: &DataRequest) -> Result<DataResponse<'d>, DataError> {
-        if let Some(resp) = self.plurals.try_load(req, &self.cldr_paths)? {
-            return Ok(resp);
-        }
-        Err(DataError::UnsupportedDataKey(req.data_key))
+        self.plurals
+            .try_load(req, &self.cldr_paths)?
+            .ok_or(DataError::UnsupportedDataKey(req.data_key))
     }
 }