Improve line termination handling and docs

src/cmd/io_commands/file.rs

@@ -31,7 +31,9 @@ fn insert<'a>(
   let mut tail = buffer.split_off(index);
   let start = buffer.len();
   for line in data {
-  buffer.push(Line::new(line).map_err(InternalError::InvalidLineText)?);
+    buffer.push(
+      Line::new(format!("{}\n", line)).map_err(InternalError::InvalidLineText)?
+    );
   }
   let end = buffer.len();
   buffer.append(&mut tail);
@@ -43,7 +45,9 @@ fn replace_buffer<'a>(
 ) -> Result<usize> {
   buffer.clear();
   for line in data {
-  buffer.push(Line::new(line).map_err(InternalError::InvalidLineText)?);
+    buffer.push(
+      Line::new(format!("{}\n", line)).map_err(InternalError::InvalidLineText)?
+    );
   }
   Ok(buffer.len())
 }
@@ -94,7 +98,7 @@ pub fn read_from_file(
         state.io.read_file(file, command == 'E')?
       },
     };
-    let data = unformated_data.split_inclusive('\n');
+    let data = unformated_data.lines();
     let datalen = match index {
       Some(i) => insert(state.history.current_mut(full_command.into()), data, i),
       None => replace_buffer(state.history.current_mut(full_command.into()), data),

src/io/mod.rs

@@ -37,6 +37,9 @@ pub trait IO {
   /// Run a read command, collecting stdout to add into buffer
   ///
   /// Stdin and Stderr should be passed through to UI
+  ///
+  /// The returned string will be split into lines and added into the buffer.
+  /// All line endings are converted into '\n' when adding into the buffer.
   fn run_read_command(&mut self,
     // UI handle. Created by setting up the UI for passing through
     // std-in/-err to child process.
@@ -49,6 +52,10 @@ pub trait IO {
   ///
   /// Stdout and Stderr should be passed through to UI
   /// Returns number of bytes written
+  ///
+  /// The LinesIter contains string slices over '\n' terminated lines. If you
+  /// with to use "\r\n" line endings in the command input this should be
+  /// handled in the IO implementation.
   fn run_write_command(&mut self,
     // UI handle. Created by setting up the UI for passing through std-in/-err
     // to child process.
@@ -63,6 +70,13 @@ pub trait IO {
   /// via stdout.
   ///
   /// Stderr should be passed through to UI
+  ///
+  /// The LinesIter contains string slices over '\n' terminated lines. If you
+  /// with to use "\r\n" line endings in the command input this should be
+  /// handled in the IO implementation.
+  ///
+  /// The returned string will be split into lines and added into the buffer.
+  /// All line endings are converted into '\n' when adding into the buffer.
   fn run_transform_command(&mut self,
     // UI handle. Created by setting up the UI for passing through
     // std-in/-out/-err to child process.
@@ -74,7 +88,12 @@ pub trait IO {
   ) -> Result<String>;
 
   /// Normal file write
+  ///
   /// Returns number of bytes written
+  ///
+  /// The LinesIter contains string slices over '\n' terminated lines. If you
+  /// with to write "\r\n" line endings into the file this should be handled in
+  /// the IO implementation.
   fn write_file(&mut self,
     // Path to file as give by user. Not checked beyond shell escape parsing
     path: &str,
@@ -85,6 +104,9 @@ pub trait IO {
   ) -> Result<usize>;
 
   /// Normal file read
+  ///
+  /// The returned string will be split into lines and added into the buffer.
+  /// All line endings are converted into '\n' when adding into the buffer.
   fn read_file(&mut self,
     // Path to file as given by user. Not checked beyond shell escape parsing
     path: &str,