hjkl_buffer/
content.rs

1//! Per-document text content. Arc-shareable across multiple [`crate::Buffer`]
2//! views.
3//!
4//! [`Content`] owns everything that belongs to the document itself:
5//!
6//! - The `lines` rope (text content).
7//! - The `dirty_gen` render-cache generation counter.
8//! - Manual folds (`folds`).
9//!
10//! [`crate::Buffer`] is the per-window wrapper. It holds an
11//! `Arc<RefCell<Content>>` plus the per-window cursor. Two `Buffer`
12//! instances that share one `Content` see the same text and folds, but
13//! each moves its cursor independently.
14//!
15//! ## Concurrency
16//!
17//! The application is single-threaded. `RefCell` is used instead of a
18//! `Mutex` — there is no runtime locking cost and the borrow checker
19//! enforces the aliasing rules at development time. Syntax workers and
20//! LSP handlers take snapshots (owned `Vec<String>` / `String`) rather
21//! than long-lived borrows, so they never hold a `RefCell` guard across
22//! an await point.
23
24use crate::folds::Fold;
25
26/// Per-document state shared across all [`crate::Buffer`] views of the
27/// same file. Wrap in `Arc<RefCell<Content>>` and pass to
28/// [`crate::Buffer::new_view`] to create an additional window onto the
29/// same content.
30///
31/// Fields intentionally parallel [`crate::Buffer`]'s pre-0.8 layout so
32/// the diff stays mechanical: `lines`, `dirty_gen`, and `folds` moved
33/// here; `cursor` stayed on `Buffer`.
34pub struct Content {
35    /// One entry per logical row. Always non-empty: a freshly
36    /// constructed `Content` holds a single empty `String` so cursor
37    /// positions never need an "is the buffer empty?" branch.
38    pub(crate) lines: Vec<String>,
39    /// Bumps on every mutation; render cache keys against this so a
40    /// per-row `Line` gets recomputed when its source row changes.
41    pub(crate) dirty_gen: u64,
42    /// Manual folds — closed ranges hide rows in the render path.
43    /// `pub(crate)` so the [`crate::folds`] module can read/write
44    /// directly (same visibility as before the split).
45    pub(crate) folds: Vec<Fold>,
46}
47
48impl Default for Content {
49    fn default() -> Self {
50        Self::new()
51    }
52}
53
54impl Content {
55    /// New empty content with one empty row.
56    pub fn new() -> Self {
57        Self {
58            lines: vec![String::new()],
59            dirty_gen: 0,
60            folds: Vec::new(),
61        }
62    }
63
64    /// Build content from a flat string. Splits on `\n`; a trailing
65    /// `\n` produces a trailing empty line.
66    #[allow(clippy::should_implement_trait)]
67    pub fn from_str(text: &str) -> Self {
68        let mut lines: Vec<String> = text.split('\n').map(str::to_owned).collect();
69        if lines.is_empty() {
70            lines.push(String::new());
71        }
72        Self {
73            lines,
74            dirty_gen: 0,
75            folds: Vec::new(),
76        }
77    }
78}
hjkl_buffer/content.rs

hjkl_buffer/
content.rs
