From 7e8ee5ed9cad6484e9f13f81731b102ced58402e Mon Sep 17 00:00:00 2001
From: Adam Carpenter <gitlab@53hor.net>
Date: Tue, 9 Jul 2019 15:14:04 -0400
Subject: Init.

---
 meap/meap-code/ch3/ch3-files-with-modes.rs | 75 ++++++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)
 create mode 100755 meap/meap-code/ch3/ch3-files-with-modes.rs

(limited to 'meap/meap-code/ch3/ch3-files-with-modes.rs')

diff --git a/meap/meap-code/ch3/ch3-files-with-modes.rs b/meap/meap-code/ch3/ch3-files-with-modes.rs
new file mode 100755
index 0000000..4440924
--- /dev/null
+++ b/meap/meap-code/ch3/ch3-files-with-modes.rs
@@ -0,0 +1,75 @@
+#[derive(Debug)]
+pub enum FileOpenMode {
+  Read,
+  Write,
+  Append,
+  Truncate,
+}
+
+#[derive(Debug)]
+pub enum FileHandle {
+  Handle(usize),
+  None,
+}
+
+#[derive(Debug)]
+pub enum FileState {
+  PendingCreation,
+  Created(FileOpenMode),
+  Opened(FileOpenMode),
+  Error(String),
+  Closed,
+  Deleted,
+}
+
+#[derive(Debug)]
+pub struct File {
+  name: String,
+  data: Vec<u8>,
+  state: FileState,
+  handle: FileHandle,
+}
+
+impl File {
+  pub fn new(name: &str) -> File {
+    File {
+      name: String::from(name),
+      data: Vec::new(),
+      state: FileState::PendingCreation, // <1>
+      handle: FileHandle::None, // <1>
+    }
+  }
+  
+  pub fn from_options(name: &str, state: FileState, handle: FileHandle) -> File {
+    File {
+      name: String::from(name),
+      data: Vec::new(),
+      state: state,
+      handle: handle,
+    }
+  }
+}
+
+fn main() {
+  let f1 = File::new("f1.txt");
+  let f2 = File::from_options("f2.txt", 
+                   FileState::Opened(FileOpenMode::Read), 
+                   FileHandle::Handle(123)
+               );
+  let f3 = File::from_options("f3.txt", 
+                   FileState::Opened(FileOpenMode::Write), 
+                   FileHandle::None
+               );
+  
+  let mut files = [f1, f2, f3];
+  
+  for f in &files {
+    println!("{:?}", f);
+  }
+  
+  // uh oh, disk failure
+  for ref mut f in &mut files {
+    f.state = FileState::Error(String::from("disk read failure"));
+    println!("{:?}", f);
+  }
+}
\ No newline at end of file
-- 
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