T17 Editor: CodeEditor with gutter, folds, minimap, rulers, guides, brackets, whitespace, cursors, multi-cursor, sticky scroll, inlay hints, lenses, decorations, ghost text, inline chat and diff (T17a); completions, signatures, hover, code actions, rename, references, outline, go to symbol, call and type hierarchy (T17b); find and replace, search panel and filters (T17c); problems, output, debug console, extensions, settings with JSON, keybindings, theme previews, welcome, recent projects, switcher, task runner (T17d); status items (T17e)

Shared: generic undo History, OverflowMenu icon and tooltip, StatusBarItem leading, six Lucide icons.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/editor/syntax.rs

@@ -0,0 +1,183 @@
+use std::ops::Range;
+
+use gpui::{App, HighlightStyle};
+
+use super::buffer::Buffer;
+use crate::forms::{Kind, code_highlights, lex};
+
+/// Each line that opens a block, and the last line the block holds, read from indentation.
+pub(crate) fn folds(buffer: &Buffer) -> Vec<(usize, usize)> {
+    let blank = |line: usize| buffer.line(line).trim().is_empty();
+    let mut out = Vec::new();
+    for line in 0..buffer.lines() {
+        if blank(line) {
+            continue;
+        }
+        let indent = buffer.indent(line);
+        let mut end = None;
+        for next in line + 1..buffer.lines() {
+            if blank(next) {
+                continue;
+            }
+            if buffer.indent(next) <= indent {
+                break;
+            }
+            end = Some(next);
+        }
+        if let Some(end) = end {
+            out.push((line, end));
+        }
+    }
+    out
+}
+
+/// A bracket in the code, how deep it sits, and where its partner is when it has one.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub(crate) struct Bracket {
+    pub offset: usize,
+    pub depth: usize,
+    pub partner: Option<usize>,
+}
+
+fn opener(close: char) -> char {
+    match close {
+        ')' => '(',
+        ']' => '[',
+        _ => '{',
+    }
+}
+
+/// Every bracket outside strings and comments; a closer takes its opener's depth.
+pub(crate) fn brackets(buffer: &Buffer) -> Vec<Bracket> {
+    let mut out: Vec<Bracket> = Vec::new();
+    let mut open: Vec<(usize, char)> = Vec::new();
+    for line in 0..buffer.lines() {
+        let start = buffer.line_range(line).start;
+        let text = buffer.line(line);
+        for (range, kind) in lex(text) {
+            if kind != Kind::Mark {
+                continue;
+            }
+            let Some(ch) = text[range.clone()].chars().next() else {
+                continue;
+            };
+            let offset = start + range.start;
+            match ch {
+                '(' | '[' | '{' => {
+                    open.push((out.len(), ch));
+                    out.push(Bracket {
+                        offset,
+                        depth: open.len() - 1,
+                        partner: None,
+                    });
+                }
+                ')' | ']' | '}' => match open.last() {
+                    Some((ix, wanted)) if *wanted == opener(ch) => {
+                        let ix = *ix;
+                        open.pop();
+                        let partner = out[ix].offset;
+                        out[ix].partner = Some(offset);
+                        out.push(Bracket {
+                            offset,
+                            depth: open.len(),
+                            partner: Some(partner),
+                        });
+                    }
+                    _ => out.push(Bracket {
+                        offset,
+                        depth: open.len(),
+                        partner: None,
+                    }),
+                },
+                _ => {}
+            }
+        }
+    }
+    out
+}
+
+/// The pair beside a caret: the bracket just after it, or else the one just before.
+pub(crate) fn matched(brackets: &[Bracket], caret: usize) -> Option<(usize, usize)> {
+    let at = |offset: usize| {
+        brackets
+            .binary_search_by_key(&offset, |bracket| bracket.offset)
+            .ok()
+            .map(|ix| brackets[ix])
+    };
+    let bracket = at(caret).or_else(|| caret.checked_sub(1).and_then(at))?;
+    Some((bracket.offset, bracket.partner?))
+}
+
+/// A line's syntax colors as highlight styles.
+pub(crate) fn colors(text: &str, cx: &App) -> Vec<(Range<usize>, HighlightStyle)> {
+    code_highlights(text, cx)
+        .into_iter()
+        .map(|(range, highlight)| {
+            (
+                range,
+                HighlightStyle {
+                    color: Some(highlight.color),
+                    background_color: highlight.background,
+                    ..HighlightStyle::default()
+                },
+            )
+        })
+        .collect()
+}
+
+/// Where `needle` appears in the lines of `range`, as offsets, whole words only when it is a word.
+pub(crate) fn occurrences(buffer: &Buffer, needle: &str, lines: Range<usize>) -> Vec<Range<usize>> {
+    if needle.is_empty() || needle.contains('\n') {
+        return Vec::new();
+    }
+    let word = needle.chars().all(|ch| ch.is_alphanumeric() || ch == '_');
+    let boundary = |ch: Option<char>| ch.is_none_or(|ch| !(ch.is_alphanumeric() || ch == '_'));
+    let mut out = Vec::new();
+    for line in lines.start..lines.end.min(buffer.lines()) {
+        let start = buffer.line_range(line).start;
+        let text = buffer.line(line);
+        for (at, _) in text.match_indices(needle) {
+            let end = at + needle.len();
+            let whole =
+                boundary(text[..at].chars().next_back()) && boundary(text[end..].chars().next());
+            if !word || whole {
+                out.push(start + at..start + end);
+            }
+        }
+    }
+    out
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn blocks_fold_by_indentation_and_skip_blank_lines() {
+        let buffer = Buffer::new("fn a() {\n    one();\n\n    two();\n}\nfn b() {}");
+        assert_eq!(folds(&buffer), [(0, 3)]);
+    }
+
+    #[test]
+    fn brackets_pair_by_depth_outside_strings_and_comments() {
+        let buffer = Buffer::new("f(a[0], \"(\") // )\n{ }");
+        let found = brackets(&buffer);
+        let offsets: Vec<usize> = found.iter().map(|bracket| bracket.offset).collect();
+        assert_eq!(
+            offsets,
+            [1, 3, 5, 11, 18, 20],
+            "the quoted and the commented ones do not count"
+        );
+        assert_eq!(found[1].depth, 1);
+        assert_eq!(found[3].partner, Some(1));
+        assert_eq!(matched(&found, 12), Some((11, 1)), "just before the caret");
+        assert_eq!(matched(&found, 18), Some((18, 20)), "just after the caret");
+    }
+
+    #[test]
+    fn occurrences_of_a_word_skip_longer_words() {
+        let buffer = Buffer::new("let total = total_cost + total;");
+        let found = occurrences(&buffer, "total", 0..1);
+        assert_eq!(found, [4..9, 25..30]);
+    }
+}