From 67cdcc2e12118becb823e20a40cc2687f2b8425a Mon Sep 17 00:00:00 2001
From: Adam Carpenter <53hornet@gmail.com>
Date: Wed, 27 Mar 2019 15:32:37 -0400
Subject: Started Rust in Action MEAP.

---
 meap/meap-code/ch3/ch3-return-result.rs | 68 +++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 meap/meap-code/ch3/ch3-return-result.rs

(limited to 'meap/meap-code/ch3/ch3-return-result.rs')

diff --git a/meap/meap-code/ch3/ch3-return-result.rs b/meap/meap-code/ch3/ch3-return-result.rs
new file mode 100644
index 0000000..da25107
--- /dev/null
+++ b/meap/meap-code/ch3/ch3-return-result.rs
@@ -0,0 +1,68 @@
+//#![allow(unused_variables)]
+
+extern crate rand;
+use rand;
+
+fn one_in_(n: usize) -> bool {
+  rand::thread_rng().gen_weighted_bool(n)
+}
+
+#[derive(Debug)]
+struct File {
+  name: String,
+  data: Vec<u8>,
+}
+
+impl File {
+  fn new(name: &str) -> File {
+    File {                     
+      name: String::from(name),  
+      data: Vec::new(),  
+    }
+  }
+
+  fn new_with_data(name: &str, data: &Vec<u8>) -> File { // <1>
+    let mut f = File::new(name);
+    f.data = data.clone();
+    f
+  }
+
+  fn read(self: &File, save_to: &mut Vec<u8>) -> usize { // <2>
+    let mut tmp = self.data.clone();
+    let read_length = tmp.len();
+    save_to.reserve(read_length);
+    save_to.append(&mut tmp);
+    read_length
+  }
+}
+
+fn open(f: &mut File) -> Result<File, String> {
+  if one_in_(10_000) {
+    return Err(String::from("Permission denied"))
+  }
+  Some(f)
+}
+
+fn close(f: &mut File) -> Result<File, String> {
+  if one_in_(100_000) {
+    return Err(String::from("Interrupted by signal!"))
+  }
+  Some(f)
+}
+
+fn main() {
+  let f3_data: Vec<u8> = vec![114, 117, 115, 116, 33]; // <4>
+  let mut f3 = File::new_with_data("2.txt", &f3_data); 
+
+  let mut buffer: Vec<u8> = vec![];
+
+  open(&mut f3);
+  let f3_length = f3.read(&mut buffer); // <5>
+  close(&mut f3);
+  
+  let text = String::from_utf8_lossy(&buffer);
+
+  println!("{:?}", f3);
+  println!("{} is {} bytes long", &f3.name, f3_length);
+  println!("{}", text);
+}
\ No newline at end of file
-- 
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