feat: configure spaces on Tab per language

src/editor.rs

@@ -13,6 +13,7 @@ use std::collections::{BTreeMap, HashMap, HashSet, VecDeque};
 use std::fmt;
 use std::fs::{self, OpenOptions};
 use std::io::{self, Read, Write};
+use std::num::NonZeroU8;
 use std::ops::Range;
 #[cfg(unix)]
 use std::os::unix::fs::{MetadataExt, OpenOptionsExt};
@@ -1778,6 +1779,8 @@ pub struct Editor {
     highlight_trailing_whitespace: bool,
     whitespace_characters: BTreeMap<char, char>,
     whitespace_scope: WhitespaceScope,
+    tab_spaces: Option<NonZeroU8>,
+    language_tab_spaces: BTreeMap<String, Option<NonZeroU8>>,
     battery_charge: Option<u8>,
     battery_label: String,
     git_blame: bool,
@@ -1883,6 +1886,8 @@ impl Editor {
             highlight_trailing_whitespace: false,
             whitespace_characters: BTreeMap::new(),
             whitespace_scope: WhitespaceScope::All,
+            tab_spaces: None,
+            language_tab_spaces: BTreeMap::new(),
             battery_charge: None,
             battery_label: String::new(),
             git_blame: true,
@@ -2653,6 +2658,15 @@ impl Editor {
         self.whitespace_scope = scope;
     }
 
+    pub(crate) fn set_tab_spaces(
+        &mut self,
+        spaces: Option<NonZeroU8>,
+        languages: BTreeMap<String, Option<NonZeroU8>>,
+    ) {
+        self.tab_spaces = spaces;
+        self.language_tab_spaces = languages;
+    }
+
     pub(crate) fn set_diff_context_options(&mut self, context_lines: usize, expand_lines: usize) {
         self.diff_context_options = (context_lines, expand_lines);
         if let Some(diff) = &mut self.diff {
@@ -8975,6 +8989,25 @@ impl Editor {
     }
 
     fn type_native(&mut self, text: &str) {
+        const SPACES: [u8; u8::MAX as usize] = [b' '; u8::MAX as usize];
+        let text = if text == "\t" {
+            let width = if self.language_tab_spaces.is_empty() {
+                self.tab_spaces
+            } else {
+                crate::syntax::language_name(
+                    self.active.path.as_deref(),
+                    self.active.lines.first().map(String::as_str),
+                )
+                .and_then(|language| self.language_tab_spaces.get(language))
+                .copied()
+                .unwrap_or(self.tab_spaces)
+            };
+            width.map_or(text, |width| {
+                std::str::from_utf8(&SPACES[..usize::from(width.get())]).expect("spaces are UTF-8")
+            })
+        } else {
+            text
+        };
         if self.edit_snippet(text, None) {
             return;
         }
@@ -23994,6 +24027,7 @@ mod tests {
     fn snippet_arguments_navigation_undo_redo_and_dot_use_resolved_text() {
         let directory = Directory::new();
         let mut editor = editor();
+        editor.set_tab_spaces(NonZeroU8::new(2), BTreeMap::new());
         type_text(&mut editor, "ica");
         editor
             .show_completion(vec![snippet_item(
@@ -24026,7 +24060,7 @@ mod tests {
         assert_eq!(editor.cursor(), Cursor { row: 0, column: 12 });
         type_text(&mut editor, ";\n\ttail");
         editor.handle(Input::Escape);
-        let resolved = "call(foo, 5);\n\ttail";
+        let resolved = "call(foo, 5);\n  tail";
         let caret = editor.cursor();
         assert_eq!(editor.context().text, resolved);
         editor.handle(Input::Char('u'));