Use from_fn for generate_messages generator

projectfluent · Apr 18, 2019 · 934dd77 · 934dd77
1 parent d55e2eb
commit 934dd77
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Showing 3 changed files with 59 additions and 73 deletions.
diff --git a/fluent-fallback/examples/simple.rs b/fluent-fallback/examples/simple.rs
@@ -27,6 +27,7 @@ use std::fs;
 use std::fs::File;
 use std::io;
 use std::io::prelude::*;
+use std::iter::from_fn;
 use std::str::FromStr;
 
 /// We need a generic file read helper function to
@@ -112,26 +113,27 @@ fn main() {
     //    the iterator over FluentBundle instances.
     let res_path_scheme = "./examples/resources/{locale}/{res_id}";
     let generate_messages = |res_ids: &[String]| {
-        let mut bundles = vec![];
+        let mut locales = locales.iter();
+        let res_mgr = &resources;
+        let res_ids = res_ids.to_vec();
 
-        for locale in locales.clone() {
-            let mut bundle = FluentBundle::new(&[&locale]);
-            let res_path = res_path_scheme.replace("{locale}", &locale);
-            for res_id in res_ids {
-                let path = res_path.replace("{res_id}", res_id);
-                let res = if let Some(res) = resources.get(&path) {
-                    res
-                } else {
-                    let source = read_file(&path).unwrap();
-                    let res = FluentResource::try_new(source).unwrap();
-                    resources.insert(path, Box::new(res))
-                };
-                bundle.add_resource(&res).unwrap();
-            }
-            bundles.push(bundle);
-        }
+        from_fn(move || {
+            locales.next().map(|locale| {
+                let mut bundle = FluentBundle::new(&[locale]);
+                let res_path = res_path_scheme.replace("{locale}", locale);
 
-        return bundles.into_iter();
+                for res_id in &res_ids {
+                    let path = res_path.replace("{res_id}", res_id);
+                    let res = res_mgr.get(&path).unwrap_or_else(|| {
+                        let source = read_file(&path).unwrap();
+                        let res = FluentResource::try_new(source).unwrap();
+                        res_mgr.insert(path, Box::new(res))
+                    });
+                    bundle.add_resource(res).unwrap();
+                }
+                bundle
+            })
+        })
     };
 
     // 6. Create a new Localization instance which will be used to maintain the localization

diff --git a/fluent-fallback/tests/localization_test.rs b/fluent-fallback/tests/localization_test.rs
@@ -6,6 +6,7 @@ use fluent_fallback::Localization;
 use std::cell::RefCell;
 use std::fs;
 use std::io;
+use std::iter::from_fn;
 
 fn read_file(path: &str) -> Result<String, io::Error> {
     fs::read_to_string(path)
@@ -17,30 +18,30 @@ fn localization_format() {
 
     let resource_ids: Vec<String> = vec!["test.ftl".into(), "test2.ftl".into()];
     let res_path_scheme = "./tests/resources/{locale}/{res_id}";
+    let locales = vec!["pl", "en-US"];
 
     let generate_messages = |res_ids: &[String]| {
-        let locales = vec!["pl", "en-US"];
-
-        let mut bundles = vec![];
-
-        for locale in locales {
-            let mut bundle = FluentBundle::new(&[locale]);
-            let res_path = res_path_scheme.replace("{locale}", locale);
-            for res_id in res_ids {
-                let path = res_path.replace("{res_id}", res_id);
-                let res = if let Some(res) = resources.get(&path) {
-                    res
-                } else {
-                    let source = read_file(&path).unwrap();
-                    let res = FluentResource::try_new(source).unwrap();
-                    resources.insert(path, Box::new(res))
-                };
-                bundle.add_resource(&res).unwrap();
-            }
-            bundles.push(bundle);
-        }
-
-        return bundles.into_iter();
+        let mut locales = locales.iter();
+        let res_mgr = &resources;
+        let res_ids = res_ids.to_vec();
+
+        from_fn(move || {
+            locales.next().map(|locale| {
+                let mut bundle = FluentBundle::new(&[locale]);
+                let res_path = res_path_scheme.replace("{locale}", locale);
+
+                for res_id in &res_ids {
+                    let path = res_path.replace("{res_id}", res_id);
+                    let res = res_mgr.get(&path).unwrap_or_else(|| {
+                        let source = read_file(&path).unwrap();
+                        let res = FluentResource::try_new(source).unwrap();
+                        res_mgr.insert(path, Box::new(res))
+                    });
+                    bundle.add_resource(res).unwrap();
+                }
+                bundle
+            })
+        })
     };
 
     let mut loc = Localization::new(resource_ids, generate_messages);

diff --git a/fluent-resmgr/src/resource_manager.rs b/fluent-resmgr/src/resource_manager.rs
@@ -2,32 +2,7 @@ use elsa::FrozenMap;
 use fluent::{FluentBundle, FluentResource};
 use std::fs;
 use std::io;
-
-pub struct BundleIterator<'l> {
-    res_mgr: &'l ResourceManager,
-    locales: Vec<String>,
-    locales_ptr: usize,
-    resource_ids: Vec<String>,
-}
-
-impl<'l> Iterator for BundleIterator<'l> {
-    type Item = FluentBundle<'l>;
-
-    fn next(&mut self) -> Option<FluentBundle<'l>> {
-        if self.locales_ptr >= self.locales.len() {
-            return None;
-        }
-        let locale = &self.locales[self.locales_ptr];
-
-        let mut bundle = FluentBundle::new(&[locale]);
-        for res_id in &self.resource_ids {
-            let res = self.res_mgr.get_resource(&res_id, locale);
-            bundle.add_resource(res).unwrap();
-        }
-        self.locales_ptr += 1;
-        Some(bundle)
-    }
-}
+use std::iter::from_fn;
 
 fn read_file(path: &str) -> Result<String, io::Error> {
     fs::read_to_string(path)
@@ -76,12 +51,20 @@ impl ResourceManager {
         &'l self,
         locales: Vec<String>,
         resource_ids: Vec<String>,
-    ) -> BundleIterator<'l> {
-        BundleIterator {
-            res_mgr: self,
-            locales,
-            locales_ptr: 0,
-            resource_ids,
-        }
+    ) -> impl Iterator<Item = FluentBundle<'l>> {
+        let res_mgr = self;
+        let mut ptr = 0;
+
+        from_fn(move || {
+            locales.get(ptr).map(|locale| {
+                ptr += 1;
+                let mut bundle = FluentBundle::new(&[locale]);
+                for res_id in &resource_ids {
+                    let res = res_mgr.get_resource(&res_id, locale);
+                    bundle.add_resource(res).unwrap();
+                }
+                bundle
+            })
+        })
     }
 }