Add support for hard tabs

Max Brunsfeld created

* Add a `hard_tabs` setting that causes indentation to be performed
  using a tab instead of multiple spaces.
* Change Buffer's indentation-related APIs to return an `IndentSize`
  struct with a length and a kind, instead of just a single u32.
* Use hard tabs by default in Go.

Change summary

crates/editor/src/editor.rs       |  71 ++++--
crates/editor/src/movement.rs     |   2 
crates/editor/src/multi_buffer.rs |  33 ++
crates/language/src/buffer.rs     | 337 +++++++++++++++++++-------------
crates/language/src/tests.rs      |  40 ++
crates/settings/src/settings.rs   |  11 +
crates/text/src/text.rs           |  12 -
crates/zed/src/main.rs            |   8 
8 files changed, 319 insertions(+), 195 deletions(-)

Detailed changes

crates/editor/src/editor.rs 🔗

@@ -32,7 +32,8 @@ use gpui::{
 pub use language::{char_kind, CharKind};
 use language::{
     BracketPair, Buffer, CodeAction, CodeLabel, Completion, Diagnostic, DiagnosticSeverity,
-    Language, OffsetRangeExt, Point, Selection, SelectionGoal, TransactionId,
+    IndentKind, IndentSize, Language, OffsetRangeExt, Point, Selection, SelectionGoal,
+    TransactionId,
 };
 use multi_buffer::MultiBufferChunks;
 pub use multi_buffer::{
@@ -50,7 +51,7 @@ use std::{
     any::TypeId,
     borrow::Cow,
     cmp::{self, Ordering, Reverse},
-    iter, mem,
+    mem,
     ops::{Deref, DerefMut, Range, RangeInclusive},
     sync::Arc,
     time::{Duration, Instant},
@@ -1923,9 +1924,8 @@ impl Editor {
                     .iter()
                     .map(|selection| {
                         let start_point = selection.start.to_point(&buffer);
-                        let indent = buffer
-                            .indent_column_for_line(start_point.row)
-                            .min(start_point.column);
+                        let mut indent = buffer.indent_size_for_line(start_point.row);
+                        indent.len = cmp::min(indent.len, start_point.column);
                         let start = selection.start;
                         let end = selection.end;
 
@@ -1958,9 +1958,9 @@ impl Editor {
                             });
                         }
 
-                        let mut new_text = String::with_capacity(1 + indent as usize);
+                        let mut new_text = String::with_capacity(1 + indent.len as usize);
                         new_text.push('\n');
-                        new_text.extend(iter::repeat(' ').take(indent as usize));
+                        new_text.extend(indent.chars());
                         if insert_extra_newline {
                             new_text = new_text.repeat(2);
                         }
@@ -3061,14 +3061,21 @@ impl Editor {
                         .buffer_snapshot
                         .buffer_line_for_row(old_head.row)
                     {
-                        let indent_column =
-                            buffer.indent_column_for_line(line_buffer_range.start.row);
+                        let indent_size = buffer.indent_size_for_line(line_buffer_range.start.row);
                         let language_name = buffer.language().map(|language| language.name());
-                        let indent = cx.global::<Settings>().tab_size(language_name.as_deref());
-                        if old_head.column <= indent_column && old_head.column > 0 {
+                        let indent_len = match indent_size.kind {
+                            IndentKind::Space => {
+                                cx.global::<Settings>().tab_size(language_name.as_deref())
+                            }
+                            IndentKind::Tab => 1,
+                        };
+                        if old_head.column <= indent_size.len && old_head.column > 0 {
                             new_head = cmp::min(
                                 new_head,
-                                Point::new(old_head.row, ((old_head.column - 1) / indent) * indent),
+                                Point::new(
+                                    old_head.row,
+                                    ((old_head.column - 1) / indent_len) * indent_len,
+                                ),
                             );
                         }
                     }
@@ -3178,26 +3185,33 @@ impl Editor {
                     }
 
                     for row in start_row..end_row {
-                        let indent_column = snapshot.indent_column_for_line(row);
-                        let columns_to_next_tab_stop = tab_size - (indent_column % tab_size);
+                        let current_indent = snapshot.indent_size_for_line(row);
+                        let indent_delta = match current_indent.kind {
+                            IndentKind::Space => {
+                                let columns_to_next_tab_stop =
+                                    tab_size - (current_indent.len % tab_size);
+                                IndentSize::spaces(columns_to_next_tab_stop)
+                            }
+                            IndentKind::Tab => IndentSize::tab(),
+                        };
                         let row_start = Point::new(row, 0);
                         buffer.edit(
                             [(
                                 row_start..row_start,
-                                " ".repeat(columns_to_next_tab_stop as usize),
+                                indent_delta.chars().collect::<String>(),
                             )],
                             cx,
                         );
 
                         // Update this selection's endpoints to reflect the indentation.
                         if row == selection.start.row {
-                            selection.start.column += columns_to_next_tab_stop as u32;
+                            selection.start.column += indent_delta.len;
                         }
                         if row == selection.end.row {
-                            selection.end.column += columns_to_next_tab_stop as u32;
+                            selection.end.column += indent_delta.len as u32;
                         }
 
-                        last_indent = Some((row, columns_to_next_tab_stop as u32));
+                        last_indent = Some((row, indent_delta.len));
                     }
                 }
             });
@@ -3230,12 +3244,19 @@ impl Editor {
                 }
 
                 for row in rows {
-                    let column = snapshot.indent_column_for_line(row);
-                    if column > 0 {
-                        let mut deletion_len = column % tab_size;
-                        if deletion_len == 0 {
-                            deletion_len = tab_size;
-                        }
+                    let indent_size = snapshot.indent_size_for_line(row);
+                    if indent_size.len > 0 {
+                        let deletion_len = match indent_size.kind {
+                            IndentKind::Space => {
+                                let columns_to_prev_tab_stop = indent_size.len % tab_size;
+                                if columns_to_prev_tab_stop == 0 {
+                                    tab_size
+                                } else {
+                                    columns_to_prev_tab_stop
+                                }
+                            }
+                            IndentKind::Tab => 1,
+                        };
                         deletion_ranges.push(Point::new(row, 0)..Point::new(row, deletion_len));
                         last_outdent = Some(row);
                     }
@@ -4549,7 +4570,7 @@ impl Editor {
                             continue;
                         }
 
-                        let start = Point::new(row, snapshot.indent_column_for_line(row));
+                        let start = Point::new(row, snapshot.indent_size_for_line(row).len);
                         let mut line_bytes = snapshot
                             .bytes_in_range(start..snapshot.max_point())
                             .flatten()

crates/editor/src/movement.rs 🔗

@@ -106,7 +106,7 @@ pub fn line_beginning(
     let soft_line_start = map.clip_point(DisplayPoint::new(display_point.row(), 0), Bias::Right);
     let indent_start = Point::new(
         point.row,
-        map.buffer_snapshot.indent_column_for_line(point.row),
+        map.buffer_snapshot.indent_size_for_line(point.row).len,
     )
     .to_display_point(map);
     let line_start = map.prev_line_boundary(point).1;

crates/editor/src/multi_buffer.rs 🔗

@@ -8,8 +8,8 @@ use gpui::{AppContext, Entity, ModelContext, ModelHandle, Task};
 pub use language::Completion;
 use language::{
     char_kind, Buffer, BufferChunks, BufferSnapshot, CharKind, Chunk, DiagnosticEntry, Event, File,
-    Language, OffsetRangeExt, Outline, OutlineItem, Selection, ToOffset as _, ToPoint as _,
-    ToPointUtf16 as _, TransactionId,
+    IndentSize, Language, OffsetRangeExt, Outline, OutlineItem, Selection, ToOffset as _,
+    ToPoint as _, ToPointUtf16 as _, TransactionId,
 };
 use settings::Settings;
 use smallvec::SmallVec;
@@ -322,9 +322,14 @@ impl MultiBuffer {
 
         if let Some(buffer) = self.as_singleton() {
             return buffer.update(cx, |buffer, cx| {
-                let language_name = buffer.language().map(|language| language.name());
-                let indent_size = cx.global::<Settings>().tab_size(language_name.as_deref());
                 if autoindent {
+                    let language_name = buffer.language().map(|language| language.name());
+                    let settings = cx.global::<Settings>();
+                    let indent_size = if settings.hard_tabs(language_name.as_deref()) {
+                        IndentSize::tab()
+                    } else {
+                        IndentSize::spaces(settings.tab_size(language_name.as_deref()))
+                    };
                     buffer.edit_with_autoindent(edits, indent_size, cx);
                 } else {
                     buffer.edit(edits, cx);
@@ -426,9 +431,15 @@ impl MultiBuffer {
                         }
                     }
                     let language_name = buffer.language().map(|l| l.name());
-                    let indent_size = cx.global::<Settings>().tab_size(language_name.as_deref());
 
                     if autoindent {
+                        let settings = cx.global::<Settings>();
+                        let indent_size = if settings.hard_tabs(language_name.as_deref()) {
+                            IndentSize::tab()
+                        } else {
+                            IndentSize::spaces(settings.tab_size(language_name.as_deref()))
+                        };
+
                         buffer.edit_with_autoindent(deletions, indent_size, cx);
                         buffer.edit_with_autoindent(insertions, indent_size, cx);
                     } else {
@@ -1787,14 +1798,16 @@ impl MultiBufferSnapshot {
         }
     }
 
-    pub fn indent_column_for_line(&self, row: u32) -> u32 {
+    pub fn indent_size_for_line(&self, row: u32) -> IndentSize {
         if let Some((buffer, range)) = self.buffer_line_for_row(row) {
-            buffer
-                .indent_column_for_line(range.start.row)
+            let mut size = buffer.indent_size_for_line(range.start.row);
+            size.len = size
+                .len
                 .min(range.end.column)
-                .saturating_sub(range.start.column)
+                .saturating_sub(range.start.column);
+            size
         } else {
-            0
+            IndentSize::spaces(0)
         }
     }
 

crates/language/src/buffer.rs 🔗

@@ -22,7 +22,7 @@ use std::{
     collections::{BTreeMap, HashMap},
     ffi::OsString,
     future::Future,
-    iter::{Iterator, Peekable},
+    iter::{self, Iterator, Peekable},
     mem,
     ops::{Deref, DerefMut, Range},
     path::{Path, PathBuf},
@@ -82,6 +82,18 @@ pub struct BufferSnapshot {
     parse_count: usize,
 }
 
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct IndentSize {
+    pub len: u32,
+    pub kind: IndentKind,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum IndentKind {
+    Space,
+    Tab,
+}
+
 #[derive(Clone, Debug)]
 struct SelectionSet {
     line_mode: bool,
@@ -215,7 +227,7 @@ struct AutoindentRequest {
     before_edit: BufferSnapshot,
     edited: Vec<Anchor>,
     inserted: Option<Vec<Range<Anchor>>>,
-    indent_size: u32,
+    indent_size: IndentSize,
 }
 
 #[derive(Debug)]
@@ -723,18 +735,18 @@ impl Buffer {
     }
 
     fn request_autoindent(&mut self, cx: &mut ModelContext<Self>) {
-        if let Some(indent_columns) = self.compute_autoindents() {
-            let indent_columns = cx.background().spawn(indent_columns);
+        if let Some(indent_sizes) = self.compute_autoindents() {
+            let indent_sizes = cx.background().spawn(indent_sizes);
             match cx
                 .background()
-                .block_with_timeout(Duration::from_micros(500), indent_columns)
+                .block_with_timeout(Duration::from_micros(500), indent_sizes)
             {
-                Ok(indent_columns) => self.apply_autoindents(indent_columns, cx),
-                Err(indent_columns) => {
+                Ok(indent_sizes) => self.apply_autoindents(indent_sizes, cx),
+                Err(indent_sizes) => {
                     self.pending_autoindent = Some(cx.spawn(|this, mut cx| async move {
-                        let indent_columns = indent_columns.await;
+                        let indent_sizes = indent_sizes.await;
                         this.update(&mut cx, |this, cx| {
-                            this.apply_autoindents(indent_columns, cx);
+                            this.apply_autoindents(indent_sizes, cx);
                         });
                     }));
                 }
@@ -742,7 +754,7 @@ impl Buffer {
         }
     }
 
-    fn compute_autoindents(&self) -> Option<impl Future<Output = BTreeMap<u32, u32>>> {
+    fn compute_autoindents(&self) -> Option<impl Future<Output = BTreeMap<u32, IndentSize>>> {
         let max_rows_between_yields = 100;
         let snapshot = self.snapshot();
         if snapshot.language.is_none()
@@ -754,7 +766,7 @@ impl Buffer {
 
         let autoindent_requests = self.autoindent_requests.clone();
         Some(async move {
-            let mut indent_columns = BTreeMap::new();
+            let mut indent_sizes = BTreeMap::new();
             for request in autoindent_requests {
                 let old_to_new_rows = request
                     .edited
@@ -768,7 +780,7 @@ impl Buffer {
                     )
                     .collect::<BTreeMap<u32, u32>>();
 
-                let mut old_suggestions = HashMap::<u32, u32>::default();
+                let mut old_suggestions = HashMap::<u32, IndentSize>::default();
                 let old_edited_ranges =
                     contiguous_ranges(old_to_new_rows.keys().copied(), max_rows_between_yields);
                 for old_edited_range in old_edited_ranges {
@@ -778,23 +790,19 @@ impl Buffer {
                         .into_iter()
                         .flatten();
                     for (old_row, suggestion) in old_edited_range.zip(suggestions) {
-                        let indentation_basis = old_to_new_rows
+                        let mut suggested_indent = old_to_new_rows
                             .get(&suggestion.basis_row)
                             .and_then(|from_row| old_suggestions.get(from_row).copied())
                             .unwrap_or_else(|| {
                                 request
                                     .before_edit
-                                    .indent_column_for_line(suggestion.basis_row)
+                                    .indent_size_for_line(suggestion.basis_row)
                             });
-                        let delta = if suggestion.indent {
-                            request.indent_size
-                        } else {
-                            0
-                        };
-                        old_suggestions.insert(
-                            *old_to_new_rows.get(&old_row).unwrap(),
-                            indentation_basis + delta,
-                        );
+                        if suggestion.indent {
+                            suggested_indent += request.indent_size;
+                        }
+                        old_suggestions
+                            .insert(*old_to_new_rows.get(&old_row).unwrap(), suggested_indent);
                     }
                     yield_now().await;
                 }
@@ -809,23 +817,18 @@ impl Buffer {
                         .into_iter()
                         .flatten();
                     for (new_row, suggestion) in new_edited_row_range.zip(suggestions) {
-                        let delta = if suggestion.indent {
-                            request.indent_size
-                        } else {
-                            0
-                        };
-                        let new_indentation = indent_columns
+                        let mut suggested_indent = indent_sizes
                             .get(&suggestion.basis_row)
                             .copied()
-                            .unwrap_or_else(|| {
-                                snapshot.indent_column_for_line(suggestion.basis_row)
-                            })
-                            + delta;
+                            .unwrap_or_else(|| snapshot.indent_size_for_line(suggestion.basis_row));
+                        if suggestion.indent {
+                            suggested_indent += request.indent_size;
+                        }
                         if old_suggestions
                             .get(&new_row)
-                            .map_or(true, |old_indentation| new_indentation != *old_indentation)
+                            .map_or(true, |old_indentation| suggested_indent != *old_indentation)
                         {
-                            indent_columns.insert(new_row, new_indentation);
+                            indent_sizes.insert(new_row, suggested_indent);
                         }
                     }
                     yield_now().await;
@@ -845,56 +848,65 @@ impl Buffer {
                             .into_iter()
                             .flatten();
                         for (row, suggestion) in inserted_row_range.zip(suggestions) {
-                            let delta = if suggestion.indent {
-                                request.indent_size
-                            } else {
-                                0
-                            };
-                            let new_indentation = indent_columns
+                            let mut suggested_indent = indent_sizes
                                 .get(&suggestion.basis_row)
                                 .copied()
                                 .unwrap_or_else(|| {
-                                    snapshot.indent_column_for_line(suggestion.basis_row)
-                                })
-                                + delta;
-                            indent_columns.insert(row, new_indentation);
+                                    snapshot.indent_size_for_line(suggestion.basis_row)
+                                });
+                            if suggestion.indent {
+                                suggested_indent += request.indent_size;
+                            }
+                            indent_sizes.insert(row, suggested_indent);
                         }
                         yield_now().await;
                     }
                 }
             }
-            indent_columns
+
+            indent_sizes
         })
     }
 
     fn apply_autoindents(
         &mut self,
-        indent_columns: BTreeMap<u32, u32>,
+        indent_sizes: BTreeMap<u32, IndentSize>,
         cx: &mut ModelContext<Self>,
     ) {
         self.autoindent_requests.clear();
         self.start_transaction();
-        for (row, indent_column) in &indent_columns {
-            self.set_indent_column_for_line(*row, *indent_column, cx);
+        for (row, indent_size) in &indent_sizes {
+            self.set_indent_size_for_line(*row, *indent_size, cx);
         }
         self.end_transaction(cx);
     }
 
-    fn set_indent_column_for_line(&mut self, row: u32, column: u32, cx: &mut ModelContext<Self>) {
-        let current_column = self.indent_column_for_line(row);
-        if column > current_column {
+    fn set_indent_size_for_line(
+        &mut self,
+        row: u32,
+        size: IndentSize,
+        cx: &mut ModelContext<Self>,
+    ) {
+        let current_size = indent_size_for_line(&self, row);
+        if size.kind != current_size.kind && current_size.len > 0 {
+            return;
+        }
+
+        if size.len > current_size.len {
             let offset = Point::new(row, 0).to_offset(&*self);
             self.edit(
                 [(
                     offset..offset,
-                    " ".repeat((column - current_column) as usize),
+                    iter::repeat(size.char())
+                        .take((size.len - current_size.len) as usize)
+                        .collect::<String>(),
                 )],
                 cx,
             );
-        } else if column < current_column {
+        } else if size.len < current_size.len {
             self.edit(
                 [(
-                    Point::new(row, 0)..Point::new(row, current_column - column),
+                    Point::new(row, 0)..Point::new(row, current_size.len - size.len),
                     "",
                 )],
                 cx,
@@ -1084,7 +1096,7 @@ impl Buffer {
     pub fn edit_with_autoindent<I, S, T>(
         &mut self,
         edits_iter: I,
-        indent_size: u32,
+        indent_size: IndentSize,
         cx: &mut ModelContext<Self>,
     ) -> Option<clock::Local>
     where
@@ -1098,7 +1110,7 @@ impl Buffer {
     pub fn edit_internal<I, S, T>(
         &mut self,
         edits_iter: I,
-        autoindent_size: Option<u32>,
+        autoindent_size: Option<IndentSize>,
         cx: &mut ModelContext<Self>,
     ) -> Option<clock::Local>
     where
@@ -1500,103 +1512,101 @@ impl Deref for Buffer {
 }
 
 impl BufferSnapshot {
+    pub fn indent_size_for_line(&self, row: u32) -> IndentSize {
+        indent_size_for_line(&self, row)
+    }
+
     fn suggest_autoindents<'a>(
         &'a self,
         row_range: Range<u32>,
     ) -> Option<impl Iterator<Item = IndentSuggestion> + 'a> {
+        // Get the "indentation ranges" that intersect this row range.
+        let grammar = self.grammar()?;
+        let prev_non_blank_row = self.prev_non_blank_row(row_range.start);
         let mut query_cursor = QueryCursorHandle::new();
-        if let Some((grammar, tree)) = self.grammar().zip(self.tree.as_ref()) {
-            let prev_non_blank_row = self.prev_non_blank_row(row_range.start);
-
-            // Get the "indentation ranges" that intersect this row range.
-            let indent_capture_ix = grammar.indents_query.capture_index_for_name("indent");
-            let end_capture_ix = grammar.indents_query.capture_index_for_name("end");
-            query_cursor.set_point_range(
-                Point::new(prev_non_blank_row.unwrap_or(row_range.start), 0).to_ts_point()
-                    ..Point::new(row_range.end, 0).to_ts_point(),
-            );
-            let mut indentation_ranges = Vec::<(Range<Point>, &'static str)>::new();
-            for mat in query_cursor.matches(
-                &grammar.indents_query,
-                tree.root_node(),
-                TextProvider(self.as_rope()),
-            ) {
-                let mut node_kind = "";
-                let mut start: Option<Point> = None;
-                let mut end: Option<Point> = None;
-                for capture in mat.captures {
-                    if Some(capture.index) == indent_capture_ix {
-                        node_kind = capture.node.kind();
-                        start.get_or_insert(Point::from_ts_point(capture.node.start_position()));
-                        end.get_or_insert(Point::from_ts_point(capture.node.end_position()));
-                    } else if Some(capture.index) == end_capture_ix {
-                        end = Some(Point::from_ts_point(capture.node.start_position().into()));
-                    }
+        let indent_capture_ix = grammar.indents_query.capture_index_for_name("indent");
+        let end_capture_ix = grammar.indents_query.capture_index_for_name("end");
+        query_cursor.set_point_range(
+            Point::new(prev_non_blank_row.unwrap_or(row_range.start), 0).to_ts_point()
+                ..Point::new(row_range.end, 0).to_ts_point(),
+        );
+        let mut indentation_ranges = Vec::<Range<Point>>::new();
+        for mat in query_cursor.matches(
+            &grammar.indents_query,
+            self.tree.as_ref()?.root_node(),
+            TextProvider(self.as_rope()),
+        ) {
+            let mut start: Option<Point> = None;
+            let mut end: Option<Point> = None;
+            for capture in mat.captures {
+                if Some(capture.index) == indent_capture_ix {
+                    start.get_or_insert(Point::from_ts_point(capture.node.start_position()));
+                    end.get_or_insert(Point::from_ts_point(capture.node.end_position()));
+                } else if Some(capture.index) == end_capture_ix {
+                    end = Some(Point::from_ts_point(capture.node.start_position().into()));
                 }
+            }
 
-                if let Some((start, end)) = start.zip(end) {
-                    if start.row == end.row {
-                        continue;
-                    }
+            if let Some((start, end)) = start.zip(end) {
+                if start.row == end.row {
+                    continue;
+                }
 
-                    let range = start..end;
-                    match indentation_ranges.binary_search_by_key(&range.start, |r| r.0.start) {
-                        Err(ix) => indentation_ranges.insert(ix, (range, node_kind)),
-                        Ok(ix) => {
-                            let prev_range = &mut indentation_ranges[ix];
-                            prev_range.0.end = prev_range.0.end.max(range.end);
-                        }
+                let range = start..end;
+                match indentation_ranges.binary_search_by_key(&range.start, |r| r.start) {
+                    Err(ix) => indentation_ranges.insert(ix, range),
+                    Ok(ix) => {
+                        let prev_range = &mut indentation_ranges[ix];
+                        prev_range.end = prev_range.end.max(range.end);
                     }
                 }
             }
+        }
 
-            let mut prev_row = prev_non_blank_row.unwrap_or(0);
-            Some(row_range.map(move |row| {
-                let row_start = Point::new(row, self.indent_column_for_line(row));
+        let mut prev_row = prev_non_blank_row.unwrap_or(0);
+        Some(row_range.map(move |row| {
+            let row_start = Point::new(row, self.indent_size_for_line(row).len);
 
-                let mut indent_from_prev_row = false;
-                let mut outdent_to_row = u32::MAX;
-                for (range, _node_kind) in &indentation_ranges {
-                    if range.start.row >= row {
-                        break;
-                    }
+            let mut indent_from_prev_row = false;
+            let mut outdent_to_row = u32::MAX;
+            for range in &indentation_ranges {
+                if range.start.row >= row {
+                    break;
+                }
 
-                    if range.start.row == prev_row && range.end > row_start {
-                        indent_from_prev_row = true;
-                    }
-                    if range.end.row >= prev_row && range.end <= row_start {
-                        outdent_to_row = outdent_to_row.min(range.start.row);
-                    }
+                if range.start.row == prev_row && range.end > row_start {
+                    indent_from_prev_row = true;
+                }
+                if range.end.row >= prev_row && range.end <= row_start {
+                    outdent_to_row = outdent_to_row.min(range.start.row);
                 }
+            }
 
-                let suggestion = if outdent_to_row == prev_row {
-                    IndentSuggestion {
-                        basis_row: prev_row,
-                        indent: false,
-                    }
-                } else if indent_from_prev_row {
-                    IndentSuggestion {
-                        basis_row: prev_row,
-                        indent: true,
-                    }
-                } else if outdent_to_row < prev_row {
-                    IndentSuggestion {
-                        basis_row: outdent_to_row,
-                        indent: false,
-                    }
-                } else {
-                    IndentSuggestion {
-                        basis_row: prev_row,
-                        indent: false,
-                    }
-                };
+            let suggestion = if outdent_to_row == prev_row {
+                IndentSuggestion {
+                    basis_row: prev_row,
+                    indent: false,
+                }
+            } else if indent_from_prev_row {
+                IndentSuggestion {
+                    basis_row: prev_row,
+                    indent: true,
+                }
+            } else if outdent_to_row < prev_row {
+                IndentSuggestion {
+                    basis_row: outdent_to_row,
+                    indent: false,
+                }
+            } else {
+                IndentSuggestion {
+                    basis_row: prev_row,
+                    indent: false,
+                }
+            };
 
-                prev_row = row;
-                suggestion
-            }))
-        } else {
-            None
-        }
+            prev_row = row;
+            suggestion
+        }))
     }
 
     fn prev_non_blank_row(&self, mut row: u32) -> Option<u32> {
@@ -1989,6 +1999,22 @@ impl BufferSnapshot {
     }
 }
 
+pub fn indent_size_for_line(text: &text::BufferSnapshot, row: u32) -> IndentSize {
+    let mut result = IndentSize::spaces(0);
+    for c in text.chars_at(Point::new(row, 0)) {
+        match (c, &result.kind) {
+            (' ', IndentKind::Space) | ('\t', IndentKind::Tab) => result.len += 1,
+            ('\t', IndentKind::Space) => {
+                if result.len == 0 {
+                    result = IndentSize::tab();
+                }
+            }
+            _ => break,
+        }
+    }
+    result
+}
+
 impl Clone for BufferSnapshot {
     fn clone(&self) -> Self {
         Self {
@@ -2311,6 +2337,43 @@ impl Default for Diagnostic {
     }
 }
 
+impl IndentSize {
+    pub fn spaces(len: u32) -> Self {
+        Self {
+            len,
+            kind: IndentKind::Space,
+        }
+    }
+
+    pub fn tab() -> Self {
+        Self {
+            len: 1,
+            kind: IndentKind::Tab,
+        }
+    }
+
+    pub fn chars(&self) -> impl Iterator<Item = char> {
+        iter::repeat(self.char()).take(self.len as usize)
+    }
+
+    pub fn char(&self) -> char {
+        match self.kind {
+            IndentKind::Space => ' ',
+            IndentKind::Tab => '\t',
+        }
+    }
+}
+
+impl std::ops::AddAssign for IndentSize {
+    fn add_assign(&mut self, other: IndentSize) {
+        if self.len == 0 {
+            *self = other;
+        } else if self.kind == other.kind {
+            self.len += other.len;
+        }
+    }
+}
+
 impl Completion {
     pub fn sort_key(&self) -> (usize, &str) {
         let kind_key = match self.lsp_completion.kind {

crates/language/src/tests.rs 🔗

@@ -576,13 +576,21 @@ fn test_edit_with_autoindent(cx: &mut MutableAppContext) {
         let text = "fn a() {}";
         let mut buffer = Buffer::new(0, text, cx).with_language(Arc::new(rust_lang()), cx);
 
-        buffer.edit_with_autoindent([(8..8, "\n\n")], 4, cx);
+        buffer.edit_with_autoindent([(8..8, "\n\n")], IndentSize::spaces(4), cx);
         assert_eq!(buffer.text(), "fn a() {\n    \n}");
 
-        buffer.edit_with_autoindent([(Point::new(1, 4)..Point::new(1, 4), "b()\n")], 4, cx);
+        buffer.edit_with_autoindent(
+            [(Point::new(1, 4)..Point::new(1, 4), "b()\n")],
+            IndentSize::spaces(4),
+            cx,
+        );
         assert_eq!(buffer.text(), "fn a() {\n    b()\n    \n}");
 
-        buffer.edit_with_autoindent([(Point::new(2, 4)..Point::new(2, 4), ".c")], 4, cx);
+        buffer.edit_with_autoindent(
+            [(Point::new(2, 4)..Point::new(2, 4), ".c")],
+            IndentSize::spaces(4),
+            cx,
+        );
         assert_eq!(buffer.text(), "fn a() {\n    b()\n        .c\n}");
 
         buffer
@@ -609,7 +617,7 @@ fn test_autoindent_does_not_adjust_lines_with_unchanged_suggestion(cx: &mut Muta
                 (empty(Point::new(1, 1)), "()"),
                 (empty(Point::new(2, 1)), "()"),
             ],
-            4,
+            IndentSize::spaces(4),
             cx,
         );
         assert_eq!(
@@ -630,7 +638,7 @@ fn test_autoindent_does_not_adjust_lines_with_unchanged_suggestion(cx: &mut Muta
                 (empty(Point::new(1, 1)), "\n.f\n.g"),
                 (empty(Point::new(2, 1)), "\n.f\n.g"),
             ],
-            4,
+            IndentSize::spaces(4),
             cx,
         );
         assert_eq!(
@@ -653,13 +661,21 @@ fn test_autoindent_does_not_adjust_lines_with_unchanged_suggestion(cx: &mut Muta
     cx.add_model(|cx| {
         let text = "fn a() {\n    {\n        b()?\n    }\n\n    Ok(())\n}";
         let mut buffer = Buffer::new(0, text, cx).with_language(Arc::new(rust_lang()), cx);
-        buffer.edit_with_autoindent([(Point::new(3, 4)..Point::new(3, 5), "")], 4, cx);
+        buffer.edit_with_autoindent(
+            [(Point::new(3, 4)..Point::new(3, 5), "")],
+            IndentSize::spaces(4),
+            cx,
+        );
         assert_eq!(
             buffer.text(),
             "fn a() {\n    {\n        b()?\n            \n\n    Ok(())\n}"
         );
 
-        buffer.edit_with_autoindent([(Point::new(3, 0)..Point::new(3, 12), "")], 4, cx);
+        buffer.edit_with_autoindent(
+            [(Point::new(3, 0)..Point::new(3, 12), "")],
+            IndentSize::spaces(4),
+            cx,
+        );
         assert_eq!(
             buffer.text(),
             "fn a() {\n    {\n        b()?\n\n\n    Ok(())\n}"
@@ -678,7 +694,7 @@ fn test_autoindent_adjusts_lines_when_only_text_changes(cx: &mut MutableAppConte
 
         let mut buffer = Buffer::new(0, text, cx).with_language(Arc::new(rust_lang()), cx);
 
-        buffer.edit_with_autoindent([(5..5, "\nb")], 4, cx);
+        buffer.edit_with_autoindent([(5..5, "\nb")], IndentSize::spaces(4), cx);
         assert_eq!(
             buffer.text(),
             "
@@ -690,7 +706,11 @@ fn test_autoindent_adjusts_lines_when_only_text_changes(cx: &mut MutableAppConte
 
         // The indentation suggestion changed because `@end` node (a close paren)
         // is now at the beginning of the line.
-        buffer.edit_with_autoindent([(Point::new(1, 4)..Point::new(1, 5), "")], 4, cx);
+        buffer.edit_with_autoindent(
+            [(Point::new(1, 4)..Point::new(1, 5), "")],
+            IndentSize::spaces(4),
+            cx,
+        );
         assert_eq!(
             buffer.text(),
             "
@@ -709,7 +729,7 @@ fn test_autoindent_with_edit_at_end_of_buffer(cx: &mut MutableAppContext) {
     cx.add_model(|cx| {
         let text = "a\nb";
         let mut buffer = Buffer::new(0, text, cx).with_language(Arc::new(rust_lang()), cx);
-        buffer.edit_with_autoindent([(0..1, "\n"), (2..3, "\n")], 4, cx);
+        buffer.edit_with_autoindent([(0..1, "\n"), (2..3, "\n")], IndentSize::spaces(4), cx);
         assert_eq!(buffer.text(), "\n\n\n");
         buffer
     });

crates/settings/src/settings.rs 🔗

@@ -25,6 +25,7 @@ pub struct Settings {
     pub default_buffer_font_size: f32,
     pub vim_mode: bool,
     pub tab_size: u32,
+    pub hard_tabs: bool,
     pub soft_wrap: SoftWrap,
     pub preferred_line_length: u32,
     pub format_on_save: bool,
@@ -35,6 +36,7 @@ pub struct Settings {
 #[derive(Clone, Debug, Default, Deserialize, JsonSchema)]
 pub struct LanguageOverride {
     pub tab_size: Option<u32>,
+    pub hard_tabs: Option<bool>,
     pub soft_wrap: Option<SoftWrap>,
     pub preferred_line_length: Option<u32>,
     pub format_on_save: Option<bool>,
@@ -80,6 +82,7 @@ impl Settings {
             default_buffer_font_size: 15.,
             vim_mode: false,
             tab_size: 4,
+            hard_tabs: false,
             soft_wrap: SoftWrap::None,
             preferred_line_length: 80,
             language_overrides: Default::default(),
@@ -106,6 +109,13 @@ impl Settings {
             .unwrap_or(self.tab_size)
     }
 
+    pub fn hard_tabs(&self, language: Option<&str>) -> bool {
+        language
+            .and_then(|language| self.language_overrides.get(language))
+            .and_then(|settings| settings.hard_tabs)
+            .unwrap_or(self.hard_tabs)
+    }
+
     pub fn soft_wrap(&self, language: Option<&str>) -> SoftWrap {
         language
             .and_then(|language| self.language_overrides.get(language))
@@ -135,6 +145,7 @@ impl Settings {
             default_buffer_font_size: 14.,
             vim_mode: false,
             tab_size: 4,
+            hard_tabs: false,
             soft_wrap: SoftWrap::None,
             preferred_line_length: 80,
             format_on_save: true,

crates/text/src/text.rs 🔗

@@ -1642,18 +1642,6 @@ impl BufferSnapshot {
             .all(|chunk| chunk.matches(|c: char| !c.is_whitespace()).next().is_none())
     }
 
-    pub fn indent_column_for_line(&self, row: u32) -> u32 {
-        let mut result = 0;
-        for c in self.chars_at(Point::new(row, 0)) {
-            if c == ' ' {
-                result += 1;
-            } else {
-                break;
-            }
-        }
-        result
-    }
-
     pub fn text_summary_for_range<'a, D, O: ToOffset>(&'a self, range: Range<O>) -> D
     where
         D: TextDimension,

crates/zed/src/main.rs 🔗

@@ -94,6 +94,14 @@ fn main() {
                 ..Default::default()
             },
         )
+        .with_overrides(
+            "Go",
+            settings::LanguageOverride {
+                tab_size: Some(4),
+                hard_tabs: Some(true),
+                ..Default::default()
+            },
+        )
         .with_overrides(
             "Markdown",
             settings::LanguageOverride {