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-rwxr-xr-xmeap/meap-code/ch3/fileresult/Cargo.toml7
-rwxr-xr-xmeap/meap-code/ch3/fileresult/src/main.rs65
2 files changed, 72 insertions, 0 deletions
diff --git a/meap/meap-code/ch3/fileresult/Cargo.toml b/meap/meap-code/ch3/fileresult/Cargo.toml
new file mode 100755
index 0000000..d5902d0
--- /dev/null
+++ b/meap/meap-code/ch3/fileresult/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "fileresult"
+version = "0.1.0"
+authors = ["Tim McNamara <code@timmcnamara.co.nz>"]
+
+[dependencies]
+rand = "0.3" \ No newline at end of file
diff --git a/meap/meap-code/ch3/fileresult/src/main.rs b/meap/meap-code/ch3/fileresult/src/main.rs
new file mode 100755
index 0000000..c02d959
--- /dev/null
+++ b/meap/meap-code/ch3/fileresult/src/main.rs
@@ -0,0 +1,65 @@
+extern crate rand; // <1>
+use rand::Rng; // <2>
+
+fn one_in(n: u32) -> bool { // <3>
+ 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() } // <4>
+ }
+
+ fn new_with_data(name: &str, data: &Vec<u8>) -> File {
+ let mut f = File::new(name);
+ f.data = data.clone();
+ f
+ }
+
+ fn read(self: &File, save_to: &mut Vec<u8>) -> Result<usize, String> { // <5>
+ let mut tmp = self.data.clone();
+ let read_length = tmp.len();
+ save_to.reserve(read_length);
+ save_to.append(&mut tmp);
+ Ok(read_length) // <6>
+ }
+}
+
+fn open(f: File) -> Result<File, String> {
+ if one_in(10_000) { // <7>
+ let err_msg = String::from("Permission denied");
+ return Err(err_msg);
+ }
+ Ok(f)
+}
+
+fn close(f: File) -> Result<File, String> {
+ if one_in(100_000) { // <8>
+ let err_msg = String::from("Interrupted by signal!");
+ return Err(err_msg);
+ }
+ Ok(f)
+}
+
+fn main() {
+ let f4_data: Vec<u8> = vec![114, 117, 115, 116, 33];
+ let mut f4 = File::new_with_data("4.txt", &f4_data);
+
+ let mut buffer: Vec<u8> = vec![];
+
+ f4 = open(f4).unwrap(); // <9>
+ let f4_length = f4.read(&mut buffer).unwrap(); // <9>
+ f4 = close(f4).unwrap(); // <9>
+
+ let text = String::from_utf8_lossy(&buffer);
+
+ println!("{:?}", f4);
+ println!("{} is {} bytes long", &f4.name, f4_length);
+ println!("{}", text);
+} \ No newline at end of file