Forward compatibility: Replace unreachable!() with Unknown enums

Author: soumya92

Cargo.toml

@@ -9,5 +9,6 @@ repository = "https://github.com/tmerr/i3ipc-rs"
 [dependencies]
 unix_socket = "0.4.5"
 byteorder = "0.3"
+log = "0.3.7"
 serde = "0.6.0"
 serde_json = "0.6.0"

README.md

@@ -59,6 +59,8 @@ fn main() {
 }
 ```
 
-## Status
+## Compatibility
 
-This library was last updated for **i3 version 4.11**. There is an open ticket concerning forward compatibility: https://github.com/tmerr/i3ipc-rs/issues/8. Contributions are welcome!
+This library was last updated for **i3 version 4.11**, but is forward compatible. Contributions are welcome!
+
+All documented functionality from i3 version 4.11 can be handled by this library. Additions to the i3 IPC interface that are not understood by this library will generally return an `Unknown` value and log a warning to the target `"i3ipc"` using the [log crate](http://doc.rust-lang.org/log). Binaries using this library should [install a logger](https://doc.rust-lang.org/log/log/index.html#in-executables) to view details of such additions.

src/common.rs

@@ -29,13 +29,19 @@ pub fn build_tree(val: &json::Value) -> reply::Node {
             "floating_con" => reply::NodeType::FloatingCon,
             "workspace" => reply::NodeType::Workspace,
             "dockarea" => reply::NodeType::DockArea,
-            _ => unreachable!()
+            other => {
+                warn!(target: "i3ipc", "Unknown NodeType {}", other);
+                reply::NodeType::Unknown
+            }
         },
         border: match val.find("border").unwrap().as_string().unwrap().as_ref() {
             "normal" => reply::NodeBorder::Normal,
             "none" => reply::NodeBorder::None,
             "pixel" => reply::NodeBorder::Pixel,
-            _ => unreachable!()
+            other => {
+                warn!(target: "i3ipc", "Unknown NodeBorder {}", other);
+                reply::NodeBorder::Unknown
+            }
         },
         current_border_width: val.find("current_border_width").unwrap().as_i64().unwrap() as i32,
         layout: match val.find("layout").unwrap().as_string().unwrap().as_ref() {
@@ -45,7 +51,10 @@ pub fn build_tree(val: &json::Value) -> reply::Node {
             "tabbed" => reply::NodeLayout::Tabbed,
             "dockarea" => reply::NodeLayout::DockArea,
             "output" => reply::NodeLayout::Output,
-            _ => unreachable!()
+            other => {
+                warn!(target: "i3ipc", "Unknown NodeLayout {}", other);
+                reply::NodeLayout::Unknown
+            }
         },
         percent: match *val.find("percent").unwrap() {
             json::Value::F64(f) => Some(f),
@@ -108,7 +117,10 @@ pub fn build_bar_config(j: &json::Value) -> reply::BarConfig {
                     "binding_mode_text" => reply::ColorableBarPart::BindingModeText,
                     "binding_mode_bg" => reply::ColorableBarPart::BindingModeBg,
                     "binding_mode_border" => reply::ColorableBarPart::BindingModeBorder,
-                    other => reply::ColorableBarPart::Undocumented(other.to_owned())
+                    other => {
+                        warn!(target: "i3ipc", "Unknown ColorableBarPart {}", other);
+                        reply::ColorableBarPart::Unknown
+                    }
                 };
                 let hex = colors.get(c).unwrap().as_string().unwrap().to_owned();
                 map.insert(enum_key, hex);

src/event.rs

@@ -41,7 +41,10 @@ impl FromStr for WorkspaceEventInfo {
                 "init" => WorkspaceChange::Init,
                 "empty" => WorkspaceChange::Empty,
                 "urgent" => WorkspaceChange::Urgent,
-                _ => unreachable!()
+                other => {
+                    warn!(target: "i3ipc", "Unknown WorkspaceChange {}", other);
+                    WorkspaceChange::Unknown
+                }
             },
             current: match val.find("current").unwrap().clone() {
                 json::Value::Null => None,
@@ -72,7 +75,10 @@ impl FromStr for OutputEventInfo {
         Ok(OutputEventInfo {
             change: match val.find("change").unwrap().as_string().unwrap().as_ref() {
                 "unspecified" => OutputChange::Unspecified,
-                _ => unreachable!()
+                other => {
+                    warn!(target: "i3ipc", "Unknown OutputChange {}", other);
+                    OutputChange::Unknown
+                }
             }
         })
     }
@@ -121,7 +127,10 @@ impl FromStr for WindowEventInfo {
                 "move" => WindowChange::Move,
                 "floating" => WindowChange::Floating,
                 "urgent" => WindowChange::Urgent,
-                _ => unreachable!()
+                other => {
+                    warn!(target: "i3ipc", "Unknown WindowChange {}", other);
+                    WindowChange::Unknown
+                }
             },
             container: common::build_tree(val.find("container").unwrap())
         })
@@ -164,7 +173,10 @@ impl FromStr for BindingEventInfo {
         Ok(BindingEventInfo {
             change: match val.find("change").unwrap().as_string().unwrap().as_ref() {
                 "run" => BindingChange::Run,
-                _ => unreachable!()
+                other => {
+                    warn!(target: "i3ipc", "Unknown BindingChange {}", other);
+                    BindingChange::Unknown
+                }
             },
             binding: Binding {
                 command: bind.find("command").unwrap().as_string().unwrap().to_owned(),
@@ -181,7 +193,10 @@ impl FromStr for BindingEventInfo {
                 input_type: match bind.find("input_type").unwrap().as_string().unwrap().as_ref() {
                     "keyboard" => InputType::Keyboard,
                     "mouse" => InputType::Mouse,
-                    _ => unreachable!()
+                    other => {
+                        warn!(target: "i3ipc", "Unknown InputType {}", other);
+                        InputType::Unknown
+                    }
                 }
             }
         })
@@ -196,13 +211,17 @@ pub mod inner {
         Focus,
         Init,
         Empty,
-        Urgent
+        Urgent,
+        /// A WorkspaceChange we don't support yet.
+        Unknown,
     }
 
     /// The kind of output change.
     #[derive(Debug)]
     pub enum OutputChange {
-        Unspecified
+        Unspecified,
+        /// An OutputChange we don't support yet.
+        Unknown,
     }
 
     /// The kind of window change.
@@ -223,14 +242,18 @@ pub mod inner {
         /// The window has transitioned to or from floating.
         Floating,
         /// The window has become urgent or lost its urgent status.
-        Urgent
+        Urgent,
+        /// A WindowChange we don't support yet.
+        Unknown,
     }
 
     /// Either keyboard or mouse.
     #[derive(Debug)]
     pub enum InputType {
         Keyboard,
-        Mouse
+        Mouse,
+        /// An InputType we don't support yet.
+        Unknown,
     }
 
     /// Contains details about the binding that was run.
@@ -258,6 +281,8 @@ pub mod inner {
     /// The kind of binding change.
     #[derive(Debug)]
     pub enum BindingChange {
-        Run
+        Run,
+        /// A BindingChange we don't support yet.
+        Unknown,
     }
 }

src/lib.rs

@@ -17,6 +17,8 @@
 
 extern crate unix_socket;
 extern crate byteorder;
+#[macro_use]
+extern crate log;
 extern crate serde;
 extern crate serde_json;
 

src/reply.rs

@@ -87,14 +87,18 @@ pub enum NodeType {
     Con,
     FloatingCon,
     Workspace,
-    DockArea
+    DockArea,
+    /// A NodeType we don't support yet.
+    Unknown,
 }
 
 #[derive(Debug)]
 pub enum NodeBorder {
     Normal,
     None,
-    Pixel
+    Pixel,
+    /// A NodeBorder we don't support yet.
+    Unknown,
 }
 
 #[derive(Debug)]
@@ -104,7 +108,9 @@ pub enum NodeLayout {
     Stacked,
     Tabbed,
     DockArea,
-    Output
+    Output,
+    /// A NodeLayout we don't support yet.
+    Unknown,
 }
 
 /// The reply to the `get_tree` request.
@@ -265,8 +271,8 @@ pub enum ColorableBarPart {
     /// Border color for the binding mode indicator.
     BindingModeBorder,
 
-    /// A colorable bar part that was not documented. (The String is its name).
-    Undocumented(String)
+    /// A ColorableBarPart we don't support yet.
+    Unknown,
 }
 
 /// The reply to the `get_bar_config` request.