result

exercises/result/src/main.rs

@@ -15,10 +15,14 @@ use std::fs::File;
 fn main() {
     let mut args = env::args();
     if let Some(file) = args.nth(1) {
-        println!("{}", read_file(&file).unwrap());        
-        /*
-        println!("{}", read_file2(&file));
-        */
+       match read_file(&file) {
+           Ok(file) => println!("{}", file),
+           Err(err) => println!("no such file or directory")
+       }
+       match read_file2(&file) {
+           Ok(file) => println!("{}", file),
+           Err(err) => println!("{}", err)
+       }
     }
 }
 
@@ -29,7 +33,14 @@ fn read_file(filename: &String) -> Result<String, io::Error> {
     Ok(content)
 }
 
-fn read_file2(filename: &String) -> String {
-    String::new()
+fn read_file2(filename: &String) -> Result<String, String> {
+    File::open(filename)
+        .map_err(|err| err.to_string())
+        .and_then(|mut file| {
+            let mut contents = String::new();
+            file.read_to_string(&mut contents)
+                .map_err(|err| err.to_string())
+                .map(|_| contents)
+        })
 }