From 435742fa8ea07645d52596b5bc39dc515c990dc8 Mon Sep 17 00:00:00 2001
From: rolo <roloedits@gmail.com>
Date: Sat, 3 May 2025 19:14:09 -0700
Subject: [PATCH] feat(commands): add `language` variable expansion

---
 book/src/command-line.md    | 1 +
 helix-view/src/expansion.rs | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/book/src/command-line.md b/book/src/command-line.md
index 7bf32bbda..b7177447c 100644
--- a/book/src/command-line.md
+++ b/book/src/command-line.md
@@ -47,6 +47,7 @@ The following variables are supported:
 | `cursor_column` | The column number of the primary cursor in the currently focused document, starting at 1. This is counted as the number of grapheme clusters from the start of the line rather than bytes or codepoints. |
 | `buffer_name` | The relative path of the currently focused document. `[scratch]` is expanded instead for scratch buffers. |
 | `line_ending` | A string containing the line ending of the currently focused document. For example on Unix systems this is usually a line-feed character (`\n`) but on Windows systems this may be a carriage-return plus a line-feed (`\r\n`). The line ending kind of the currently focused document can be inspected with the `:line-ending` command. |
+| `language` | A string containing the language name of the currently focused document.|
 
 Aside from editor variables, the following expansions may be used:
 
diff --git a/helix-view/src/expansion.rs b/helix-view/src/expansion.rs
index 96a71b8e5..77d96cb31 100644
--- a/helix-view/src/expansion.rs
+++ b/helix-view/src/expansion.rs
@@ -33,6 +33,8 @@ pub enum Variable {
     BufferName,
     /// A string containing the line-ending of the currently focused document.
     LineEnding,
+    // The name of current buffers language as set in `languages.toml`
+    Language,
 }
 
 impl Variable {
@@ -41,6 +43,7 @@ impl Variable {
         Self::CursorColumn,
         Self::BufferName,
         Self::LineEnding,
+        Self::Language,
     ];
 
     pub const fn as_str(&self) -> &'static str {
@@ -49,6 +52,7 @@ impl Variable {
             Self::CursorColumn => "cursor_column",
             Self::BufferName => "buffer_name",
             Self::LineEnding => "line_ending",
+            Self::Language => "language",
         }
     }
 
@@ -58,6 +62,7 @@ impl Variable {
             "cursor_column" => Some(Self::CursorColumn),
             "buffer_name" => Some(Self::BufferName),
             "line_ending" => Some(Self::LineEnding),
+            "language" => Some(Self::Language),
             _ => None,
         }
     }
@@ -215,5 +220,8 @@ fn expand_variable(editor: &Editor, variable: Variable) -> Result<Cow<'static, s
             }
         }
         Variable::LineEnding => Ok(Cow::Borrowed(doc.line_ending.as_str())),
+        Variable::Language => Ok(Cow::Owned(
+            doc.language_name().unwrap_or("text").to_string(),
+        )),
     }
 }