Return style fix

[learn-rust.git] / src / main.rs

diff --git a/src/main.rs b/src/main.rs
index 973bb2e6c8a3ff790ed25a03f690ea48c6a29084..c07c4051165861365a2176a3c1edec6957d16903 100644 (file)
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,7 +2,7 @@ mod word_utils;
 
 use std::collections::HashMap;
 use std::io::{prelude::*, ErrorKind};
 
 use std::collections::HashMap;
 use std::io::{prelude::*, ErrorKind};

-use std::fs::File;
+use std::fs::{self, File};

 
 use word_utils::{first_word, second_word};
 
 
 use word_utils::{first_word, second_word};
 


@@ -69,6 +69,13 @@ fn test_hashmaps() {
     println!("collect_scores after rebuilding with doubling: {:?}", collect_scores);
 }
 
     println!("collect_scores after rebuilding with doubling: {:?}", collect_scores);
 }
 

+fn read_file(path: &str) -> Result<String, std::io::Error> {
+    let mut s = String::new();
+    File::open(path)?
+        .read_to_string(&mut s)?;
+    Ok(s)
+}
+

 fn test_files() {
     if let Ok(mut f) = File::open("Cargo.toml") {
         let mut contents = String::new();
 fn test_files() {
     if let Ok(mut f) = File::open("Cargo.toml") {
         let mut contents = String::new();


@@ -95,6 +102,18 @@ fn test_files() {
         panic!("Could not read file: {:?}", e);
     });
     println!("successfully opened Cargo.toml with unwrap_or_else: {:?}, contents {} bytes:\n{}\n----------", f, len, contents);
         panic!("Could not read file: {:?}", e);
     });
     println!("successfully opened Cargo.toml with unwrap_or_else: {:?}, contents {} bytes:\n{}\n----------", f, len, contents);

+
+    // using the '?' operator
+    match read_file("Cargo.toml") {
+        Ok(s) => println!("Cargo.toml contents:\n{}\n-------------", s),
+        Err(e) => println!("Could not open Cargo.toml: {:?}", e)
+    }
+
+    // using std API
+    match fs::read_to_string("Cargo.toml") {
+        Ok(s) => println!("Cargo.toml contents:\n{}\n-------------", s),
+        Err(e) => println!("Could not open Cargo.toml: {:?}", e)
+    }

 }
 
 fn main() {
 }
 
 fn main() {