toggling of block comments (#4718)

2 files changed, 125 insertions, 14 deletions

diff --git a/helix-term/src/commands.rs b/helix-term/src/commands.rs
index fdad31a8..bd0a60b7 100644
--- a/helix-term/src/commands.rs
+++ b/helix-term/src/commands.rs
@@ -12,7 +12,7 @@ pub use typed::*;
 use helix_core::{
     char_idx_at_visual_offset, comment,
     doc_formatter::TextFormat,
-    encoding, find_first_non_whitespace_char, find_workspace, graphemes,
+    encoding, find_workspace, graphemes,
     history::UndoKind,
     increment, indent,
     indent::IndentStyle,
@@ -23,7 +23,7 @@ use helix_core::{
     regex::{self, Regex},
     search::{self, CharMatcher},
     selection, shellwords, surround,
-    syntax::LanguageServerFeature,
+    syntax::{BlockCommentToken, LanguageServerFeature},
     text_annotations::TextAnnotations,
     textobject,
     tree_sitter::Node,
@@ -415,6 +415,8 @@ impl MappableCommand {
         completion, "Invoke completion popup",
         hover, "Show docs for item under cursor",
         toggle_comments, "Comment/uncomment selections",
+        toggle_line_comments, "Line comment/uncomment selections",
+        toggle_block_comments, "Block comment/uncomment selections",
         rotate_selections_forward, "Rotate selections forward",
         rotate_selections_backward, "Rotate selections backward",
         rotate_selection_contents_forward, "Rotate selection contents forward",
@@ -822,7 +824,7 @@ fn kill_to_line_start(cx: &mut Context) {
             let head = if anchor == first_char && line != 0 {
                 // select until previous line
                 line_end_char_index(&text, line - 1)
-            } else if let Some(pos) = find_first_non_whitespace_char(text.line(line)) {
+            } else if let Some(pos) = text.line(line).first_non_whitespace_char() {
                 if first_char + pos < anchor {
                     // select until first non-blank in line if cursor is after it
                     first_char + pos
@@ -884,7 +886,7 @@ fn goto_first_nonwhitespace_impl(view: &mut View, doc: &mut Document, movement:
     let selection = doc.selection(view.id).clone().transform(|range| {
         let line = range.cursor_line(text);
 
-        if let Some(pos) = find_first_non_whitespace_char(text.line(line)) {
+        if let Some(pos) = text.line(line).first_non_whitespace_char() {
             let pos = pos + text.line_to_char(line);
             range.put_cursor(text, pos, movement == Movement::Extend)
         } else {
@@ -3087,11 +3089,11 @@ fn insert_with_indent(cx: &mut Context, cursor_fallback: IndentFallbackPos) {
         } else {
             // move cursor to the fallback position
             let pos = match cursor_fallback {
-                IndentFallbackPos::LineStart => {
-                    find_first_non_whitespace_char(text.line(cursor_line))
-                        .map(|ws_offset| ws_offset + cursor_line_start)
-                        .unwrap_or(cursor_line_start)
-                }
+                IndentFallbackPos::LineStart => text
+                    .line(cursor_line)
+                    .first_non_whitespace_char()
+                    .map(|ws_offset| ws_offset + cursor_line_start)
+                    .unwrap_or(cursor_line_start),
                 IndentFallbackPos::LineEnd => line_end_char_index(&text, cursor_line),
             };
 
@@ -4462,18 +4464,124 @@ pub fn completion(cx: &mut Context) {
 }
 
 // comments
-fn toggle_comments(cx: &mut Context) {
+type CommentTransactionFn = fn(
+    line_token: Option<&str>,
+    block_tokens: Option<&[BlockCommentToken]>,
+    doc: &Rope,
+    selection: &Selection,
+) -> Transaction;
+
+fn toggle_comments_impl(cx: &mut Context, comment_transaction: CommentTransactionFn) {
     let (view, doc) = current!(cx.editor);
-    let token = doc
+    let line_token: Option<&str> = doc
+        .language_config()
+        .and_then(|lc| lc.comment_tokens.as_ref())
+        .and_then(|tc| tc.first())
+        .map(|tc| tc.as_str());
+    let block_tokens: Option<&[BlockCommentToken]> = doc
         .language_config()
-        .and_then(|lc| lc.comment_token.as_ref())
-        .map(|tc| tc.as_ref());
-    let transaction = comment::toggle_line_comments(doc.text(), doc.selection(view.id), token);
+        .and_then(|lc| lc.block_comment_tokens.as_ref())
+        .map(|tc| &tc[..]);
+
+    let transaction =
+        comment_transaction(line_token, block_tokens, doc.text(), doc.selection(view.id));
 
     doc.apply(&transaction, view.id);
     exit_select_mode(cx);
 }
 
+/// commenting behavior:
+/// 1. only line comment tokens -> line comment
+/// 2. each line block commented -> uncomment all lines
+/// 3. whole selection block commented -> uncomment selection
+/// 4. all lines not commented and block tokens -> comment uncommented lines
+/// 5. no comment tokens and not block commented -> line comment
+fn toggle_comments(cx: &mut Context) {
+    toggle_comments_impl(cx, |line_token, block_tokens, doc, selection| {
+        let text = doc.slice(..);
+
+        // only have line comment tokens
+        if line_token.is_some() && block_tokens.is_none() {
+            return comment::toggle_line_comments(doc, selection, line_token);
+        }
+
+        let split_lines = comment::split_lines_of_selection(text, selection);
+
+        let default_block_tokens = &[BlockCommentToken::default()];
+        let block_comment_tokens = block_tokens.unwrap_or(default_block_tokens);
+
+        let (line_commented, line_comment_changes) =
+            comment::find_block_comments(block_comment_tokens, text, &split_lines);
+
+        // block commented by line would also be block commented so check this first
+        if line_commented {
+            return comment::create_block_comment_transaction(
+                doc,
+                &split_lines,
+                line_commented,
+                line_comment_changes,
+            )
+            .0;
+        }
+
+        let (block_commented, comment_changes) =
+            comment::find_block_comments(block_comment_tokens, text, selection);
+
+        // check if selection has block comments
+        if block_commented {
+            return comment::create_block_comment_transaction(
+                doc,
+                selection,
+                block_commented,
+                comment_changes,
+            )
+            .0;
+        }
+
+        // not commented and only have block comment tokens
+        if line_token.is_none() && block_tokens.is_some() {
+            return comment::create_block_comment_transaction(
+                doc,
+                &split_lines,
+                line_commented,
+                line_comment_changes,
+            )
+            .0;
+        }
+
+        // not block commented at all and don't have any tokens
+        comment::toggle_line_comments(doc, selection, line_token)
+    })
+}
+
+fn toggle_line_comments(cx: &mut Context) {
+    toggle_comments_impl(cx, |line_token, block_tokens, doc, selection| {
+        if line_token.is_none() && block_tokens.is_some() {
+            let default_block_tokens = &[BlockCommentToken::default()];
+            let block_comment_tokens = block_tokens.unwrap_or(default_block_tokens);
+            comment::toggle_block_comments(
+                doc,
+                &comment::split_lines_of_selection(doc.slice(..), selection),
+                block_comment_tokens,
+            )
+        } else {
+            comment::toggle_line_comments(doc, selection, line_token)
+        }
+    });
+}
+
+fn toggle_block_comments(cx: &mut Context) {
+    toggle_comments_impl(cx, |line_token, block_tokens, doc, selection| {
+        if line_token.is_some() && block_tokens.is_none() {
+            comment::toggle_line_comments(doc, selection, line_token)
+        } else {
+            let default_block_tokens = &[BlockCommentToken::default()];
+            let block_comment_tokens = block_tokens.unwrap_or(default_block_tokens);
+            comment::toggle_block_comments(doc, selection, block_comment_tokens)
+        }
+    });
+}
+
 fn rotate_selections(cx: &mut Context, direction: Direction) {
     let count = cx.count();
     let (view, doc) = current!(cx.editor);
diff --git a/helix-term/src/keymap/default.rs b/helix-term/src/keymap/default.rs
index 92d6b590..bab662b0 100644
--- a/helix-term/src/keymap/default.rs
+++ b/helix-term/src/keymap/default.rs
@@ -276,6 +276,9 @@ pub fn default() -> HashMap<Mode, KeyTrie> {
             "k" => hover,
             "r" => rename_symbol,
             "h" => select_references_to_symbol_under_cursor,
+            "c" => toggle_comments,
+            "C" => toggle_block_comments,
+            "A-c" => toggle_line_comments,
             "?" => command_palette,
         },
         "z" => { "View"