add statusline element to display file line endings (helix-editor#3113)

* add statusline element to display file line endings

* run cargo fmt --all

* change the word *ending* from plural to singular

* support for the unicode-lines feature flag

Author: axdank

book/src/configuration.md

@@ -62,7 +62,7 @@ Statusline elements can be defined as follows:
 [editor.statusline]
 left = ["mode", "spinner"]
 center = ["file-name"]
-right = ["diagnostics", "selections", "position", "file-encoding", "file-type"]
+right = ["diagnostics", "selections", "position", "file-encoding", "file-line-ending", "file-type"]
 ```
 
 The following elements can be configured:
@@ -73,6 +73,7 @@ The following elements can be configured:
 | `spinner` | A progress spinner indicating LSP activity |
 | `file-name` | The path/name of the opened file |
 | `file-encoding` | The encoding of the opened file if it differs from UTF-8 |
+| `file-line-ending` | The file line endings (CRLF or LF) |
 | `file-type` | The type of the opened file |
 | `diagnostics` | The number of warnings and/or errors |
 | `selections` | The number of active selections |

helix-term/src/commands/typed.rs

@@ -413,12 +413,11 @@ fn set_line_ending(
 
     // Attempt to parse argument as a line ending.
     let line_ending = match arg {
-        // We check for CR first because it shares a common prefix with CRLF.
-        #[cfg(feature = "unicode-lines")]
-        arg if arg.starts_with("cr") => CR,
         arg if arg.starts_with("crlf") => Crlf,
         arg if arg.starts_with("lf") => LF,
         #[cfg(feature = "unicode-lines")]
+        arg if arg.starts_with("cr") => CR,
+        #[cfg(feature = "unicode-lines")]
         arg if arg.starts_with("ff") => FF,
         #[cfg(feature = "unicode-lines")]
         arg if arg.starts_with("nel") => Nel,

helix-term/src/ui/statusline.rs

@@ -138,6 +138,7 @@ where
         helix_view::editor::StatusLineElement::Spinner => render_lsp_spinner,
         helix_view::editor::StatusLineElement::FileName => render_file_name,
         helix_view::editor::StatusLineElement::FileEncoding => render_file_encoding,
+        helix_view::editor::StatusLineElement::FileLineEnding => render_file_line_ending,
         helix_view::editor::StatusLineElement::FileType => render_file_type,
         helix_view::editor::StatusLineElement::Diagnostics => render_diagnostics,
         helix_view::editor::StatusLineElement::Selections => render_selections,
@@ -280,6 +281,31 @@ where
     }
 }
 
+fn render_file_line_ending<F>(context: &mut RenderContext, write: F)
+where
+    F: Fn(&mut RenderContext, String, Option<Style>) + Copy,
+{
+    use helix_core::LineEnding::*;
+    let line_ending = match context.doc.line_ending {
+        Crlf => "CRLF",
+        LF => "LF",
+        #[cfg(feature = "unicode-lines")]
+        VT => "VT", // U+000B -- VerticalTab
+        #[cfg(feature = "unicode-lines")]
+        FF => "FF", // U+000C -- FormFeed
+        #[cfg(feature = "unicode-lines")]
+        CR => "CR", // U+000D -- CarriageReturn
+        #[cfg(feature = "unicode-lines")]
+        Nel => "NEL", // U+0085 -- NextLine
+        #[cfg(feature = "unicode-lines")]
+        LS => "LS", // U+2028 -- Line Separator
+        #[cfg(feature = "unicode-lines")]
+        PS => "PS", // U+2029 -- ParagraphSeparator
+    };
+
+    write(context, format!(" {} ", line_ending), None);
+}
+
 fn render_file_type<F>(context: &mut RenderContext, write: F)
 where
     F: Fn(&mut RenderContext, String, Option<Style>) + Copy,

helix-view/src/editor.rs

@@ -297,6 +297,9 @@ pub enum StatusLineElement {
     /// The file encoding
     FileEncoding,
 
+    /// The file line endings (CRLF or LF)
+    FileLineEnding,
+
     /// The file type (language ID or "text")
     FileType,