Add tab_width and indent_unit config.

2 files changed, 31 insertions, 12 deletions

diff --git a/helix-core/src/indent.rs b/helix-core/src/indent.rs
index 9b1241e5..775bc8ba 100644
--- a/helix-core/src/indent.rs
+++ b/helix-core/src/indent.rs
@@ -8,19 +8,17 @@ use crate::{
 /// To determine indentation of a newly inserted line, figure out the indentation at the last col
 /// of the previous line.
 
-pub const TAB_WIDTH: usize = 4;
-
-fn indent_level_for_line(line: RopeSlice) -> usize {
+fn indent_level_for_line(line: RopeSlice, tab_width: usize) -> usize {
     let mut len = 0;
     for ch in line.chars() {
         match ch {
-            '\t' => len += TAB_WIDTH,
+            '\t' => len += tab_width,
             ' ' => len += 1,
             _ => break,
         }
     }
 
-    len / TAB_WIDTH
+    len / tab_width
 }
 
 /// Find the highest syntax node at position.
@@ -162,9 +160,14 @@ fn calculate_indentation(node: Option<Node>, newline: bool) -> usize {
     increment as usize
 }
 
-fn suggested_indent_for_line(syntax: Option<&Syntax>, text: RopeSlice, line_num: usize) -> usize {
+fn suggested_indent_for_line(
+    syntax: Option<&Syntax>,
+    text: RopeSlice,
+    line_num: usize,
+    tab_width: usize,
+) -> usize {
     let line = text.line(line_num);
-    let current = indent_level_for_line(line);
+    let current = indent_level_for_line(line, tab_width);
 
     if let Some(start) = find_first_non_whitespace_char(text, line_num) {
         return suggested_indent_for_pos(syntax, text, start, false);
@@ -202,13 +205,14 @@ mod test {
 
     #[test]
     fn test_indent_level() {
+        let tab_width = 4;
         let line = Rope::from("        fn new"); // 8 spaces
-        assert_eq!(indent_level_for_line(line.slice(..)), 2);
+        assert_eq!(indent_level_for_line(line.slice(..), tab_width), 2);
         let line = Rope::from("\t\t\tfn new"); // 3 tabs
-        assert_eq!(indent_level_for_line(line.slice(..)), 3);
+        assert_eq!(indent_level_for_line(line.slice(..), tab_width), 3);
         // mixed indentation
         let line = Rope::from("\t    \tfn new"); // 1 tab, 4 spaces, tab
-        assert_eq!(indent_level_for_line(line.slice(..)), 3);
+        assert_eq!(indent_level_for_line(line.slice(..), tab_width), 3);
     }
 
     #[test]
@@ -295,12 +299,13 @@ where
         let highlight_config = language_config.highlight_config(&[]).unwrap();
         let syntax = Syntax::new(&doc, highlight_config.clone());
         let text = doc.slice(..);
+        let tab_width = 4;
 
         for i in 0..doc.len_lines() {
             let line = text.line(i);
-            let indent = indent_level_for_line(line);
+            let indent = indent_level_for_line(line, tab_width);
             assert_eq!(
-                suggested_indent_for_line(Some(&syntax), text, i),
+                suggested_indent_for_line(Some(&syntax), text, i, tab_width),
                 indent,
                 "line {}: {}",
                 i,
diff --git a/helix-core/src/syntax.rs b/helix-core/src/syntax.rs
index c352f8f2..63e39f8f 100644
--- a/helix-core/src/syntax.rs
+++ b/helix-core/src/syntax.rs
@@ -29,6 +29,7 @@ pub struct LanguageConfiguration {
     pub(crate) highlight_config: OnceCell<Option<Arc<HighlightConfiguration>>>,
     // tags_config OnceCell<> https://github.com/tree-sitter/tree-sitter/pull/583
     pub language_server_config: Option<LanguageServerConfiguration>,
+    pub indent_config: Option<IndentationConfiguration>,
 }
 
 pub struct LanguageServerConfiguration {
@@ -36,6 +37,11 @@ pub struct LanguageServerConfiguration {
     pub args: Vec<String>,
 }
 
+pub struct IndentationConfiguration {
+    pub tab_width: usize,
+    pub indent_unit: String,
+}
+
 impl LanguageConfiguration {
     pub fn highlight_config(&self, scopes: &[String]) -> Option<Arc<HighlightConfiguration>> {
         self.highlight_config
@@ -104,6 +110,10 @@ impl Loader {
                     command: "rust-analyzer".to_string(),
                     args: vec![],
                 }),
+                indent_config: Some(IndentationConfiguration {
+                    tab_width: 4,
+                    indent_unit: String::from("    "),
+                }),
             },
             LanguageConfiguration {
                 scope: "source.toml".to_string(),
@@ -114,6 +124,10 @@ impl Loader {
                 path: "../helix-syntax/languages/tree-sitter-toml".into(),
                 roots: vec![],
                 language_server_config: None,
+                indent_config: Some(IndentationConfiguration {
+                    tab_width: 2,
+                    indent_unit: String::from("  "),
+                }),
             },
         ];