Update examples with "for_each"

Remove intermediate variable

src/app.md

@@ -234,7 +234,9 @@ fn run() -> Result<()> {
     let file = File::open("archive.tar.gz")?;
     let mut archive = Archive::new(GzDecoder::new(file)?);
     let prefix = "bundle/logs";
-    let entries = archive
+
+    println!("Extracted the following files:");
+    archive
         .entries()?
         .filter_map(|e| e.ok())
         .map(|mut entry| -> Result<PathBuf> {
@@ -242,12 +244,10 @@ fn run() -> Result<()> {
             let path = entry.path()?.strip_prefix(prefix)?.to_owned();
             entry.unpack(&path)?;
             Ok(path)
-        });
+        })
+        .filter_map(|e| e.ok())
+        .for_each(|x| println!("> {}", x.display()));
 
-    println!("Extracted the following files:");
-    for path in entries.filter_map(|e| e.ok()) {
-        println!("> {}", path.display());
-    }
     Ok(())
 }
 #
@@ -467,12 +467,11 @@ fn is_not_hidden(entry: &DirEntry) -> bool {
 }
 
 fn main() {
-    for result in WalkDir::new(".")
-            .into_iter()
-            .filter_entry(|e| is_not_hidden(e))
-            .filter_map(|v| v.ok()) {
-        println!("{}", result.path().display());
-    }
+    WalkDir::new(".")
+        .into_iter()
+        .filter_entry(|e| is_not_hidden(e))
+        .filter_map(|v| v.ok())
+        .for_each(|x| println!("{}", x.path().display()));
 }
 ```
 

src/basics.md

@@ -309,8 +309,7 @@ fn run() -> Result<()> {
                                ([0-9a-fA-F]+) # commit hash
                                (.*)           # The commit message")?;
 
-    let stdout = String::from_utf8(output.stdout)?;
-    let commits = stdout
+    String::from_utf8(output.stdout)?
         .lines()
         .filter_map(|line| pattern.captures(line))
         .map(|cap| {
@@ -319,11 +318,8 @@ fn run() -> Result<()> {
                      message: cap[2].trim().to_string(),
                  }
              })
-        .take(5);
-
-    for commit in commits {
-        println!("{:?}", commit);
-    }
+        .take(5)
+        .for_each(|x| println!("{:?}", x));
 
     Ok(())
 }
@@ -491,14 +487,11 @@ fn run() -> Result<()> {
     ]).case_insensitive(true)
         .build()?;
 
-    let filtered = buffered
+    buffered
         .lines()
         .filter_map(|line| line.ok())
-        .filter(|line| set.is_match(line.as_str()));
-
-    for line in filtered {
-        println!("{}", line);
-    }
+        .filter(|line| set.is_match(line.as_str()))
+        .for_each(|x| println!("{}", x));
 
     Ok(())
 }
@@ -586,9 +579,7 @@ fn run() -> Result<()> {
         // acquire access
         let db = FRUIT.lock().map_err(|_| "Failed to acquire MutexGuard")?;
 
-        for (i, item) in db.iter().enumerate() {
-            println!("{}: {}", i, item);
-        }
+        db.iter().enumerate().for_each(|(i, item)| println!("{}: {}", i, item));
         // release access
     }
     insert("grape")?;

src/concurrency.md

@@ -131,9 +131,7 @@ fn run() -> Result<()> {
         .filter_map(|x| x.err())
         .collect();
 
-    for failure in &image_failures {
-        println!("{}", failure.display_chain());
-    }
+    image_failures.iter().for_each(|x| println!("{}", x.display_chain()));
 
     println!("{} thumbnails saved successfully", files.len() - image_failures.len());
     Ok(())

src/net.md

@@ -860,14 +860,10 @@ use select::predicate::Name;
 fn run() -> Result<()> {
     let res = reqwest::get("https://www.rust-lang.org/en-US/")?;
 
-    let document = Document::from_read(res)?;
-
-    let links = document.find(Name("a"))
-        .filter_map(|n| n.attr("href"));
-
-    for link in links {
-        println!("{}", link);
-    }
+    Document::from_read(res)?
+        .find(Name("a"))
+        .filter_map(|n| n.attr("href"))
+        .for_each(|x| println!("{}", x));
 
     Ok(())
 }
@@ -940,9 +936,10 @@ fn run() -> Result<()> {
         .filter_map(|link| base_parser.parse(link).ok())
         .collect();
 
-    for link in links.iter().filter(|link| check_link(link).ok() == Some(false)) {
-        println!("{} is broken.", link);
-    }
+    links
+        .iter()
+        .filter(|link| check_link(link).ok() == Some(false))
+        .for_each(|x| println!("{} is broken.", x));
 
     Ok(())
 }