mirror of
https://github.com/helix-editor/helix.git
synced 2024-12-18 05:51:54 +04:00
112 lines
4.7 KiB
Markdown
112 lines
4.7 KiB
Markdown
|
|
| Crate | Description |
|
|
| ----------- | ----------- |
|
|
| helix-core | Core editing primitives, functional. |
|
|
| helix-lsp | Language server client |
|
|
| helix-dap | Debug Adapter Protocol (DAP) client |
|
|
| helix-loader | Functions for building, fetching, and loading external resources |
|
|
| helix-view | UI abstractions for use in backends, imperative shell. |
|
|
| helix-term | Terminal UI |
|
|
| helix-tui | TUI primitives, forked from tui-rs, inspired by Cursive |
|
|
|
|
|
|
This document contains a high-level overview of Helix internals.
|
|
|
|
> NOTE: Use `cargo doc --open` for API documentation as well as dependency
|
|
> documentation.
|
|
|
|
## Core
|
|
|
|
The core contains basic building blocks used to construct the editor. It is
|
|
heavily based on [CodeMirror 6](https://codemirror.net/6/docs/). The primitives
|
|
are functional: most operations won't modify data in place but instead return
|
|
a new copy.
|
|
|
|
The main data structure used for representing buffers is a `Rope`. We re-export
|
|
the excellent [ropey](https://github.com/cessen/ropey) library. Ropes are cheap
|
|
to clone, and allow us to easily make snapshots of a text state.
|
|
|
|
Multiple selections are a core editing primitive. Document selections are
|
|
represented by a `Selection`. Each `Range` in the selection consists of a moving
|
|
`head` and an immovable `anchor`. A single cursor in the editor is simply
|
|
a selection with a single range, with the head and the anchor in the same
|
|
position.
|
|
|
|
Ropes are modified by constructing an OT-like `Transaction`. It represents
|
|
a single coherent change to the document and can be applied to the rope.
|
|
A transaction can be inverted to produce an undo. Selections and marks can be
|
|
mapped over a transaction to translate to a position in the new text state after
|
|
applying the transaction.
|
|
|
|
> NOTE: `Transaction::change`/`Transaction::change_by_selection` is the main
|
|
> interface used to generate text edits.
|
|
|
|
`Syntax` is the interface used to interact with tree-sitter ASTs for syntax
|
|
highlighting and other features.
|
|
|
|
## View
|
|
|
|
The `view` layer was supposed to be a frontend-agnostic imperative library that
|
|
would build on top of `core` to provide the common editor logic. Currently it's
|
|
tied to the terminal UI.
|
|
|
|
A `Document` ties together the `Rope`, `Selection`(s), `Syntax`, document
|
|
`History`, language server (etc.) into a comprehensive representation of an open
|
|
file.
|
|
|
|
A `View` represents an open split in the UI. It holds the currently open
|
|
document ID and other related state. Views encapsulate the gutter, status line,
|
|
diagnostics, and the inner area where the code is displayed.
|
|
|
|
> NOTE: Multiple views are able to display the same document, so the document
|
|
> contains selections for each view. To retrieve, `document.selection()` takes
|
|
> a `ViewId`.
|
|
|
|
`Info` is the autoinfo box that shows hints when awaiting another key with bindings
|
|
like `g` and `m`. It is attached to the viewport as a whole.
|
|
|
|
`Surface` is like a buffer to which widgets draw themselves to, and the
|
|
surface is then rendered on the screen on each cycle.
|
|
|
|
`Rect`s are areas (simply an x and y coordinate with the origin at the
|
|
screen top left and then a height and width) which are part of a
|
|
`Surface`. They can be used to limit the area to which a `Component` can
|
|
render. For example if we wrap a `Markdown` component in a `Popup`
|
|
(think the documentation popup with space+k), Markdown's render method
|
|
will get a Rect that is the exact size of the popup.
|
|
|
|
Widgets are called `Component`s internally, and you can see most of them
|
|
in `helix-term/src/ui`. Some components like `Popup` and `Overlay` can take
|
|
other components as children.
|
|
|
|
`Layer`s are how multiple components are displayed, and is simply a
|
|
`Vec<Component>`. Layers are managed by the `Compositor`. On each top
|
|
level render call, the compositor renders each component in the order
|
|
they were pushed into the stack. This makes multiple components "layer"
|
|
on top of one another. Hence we get a file picker displayed over the
|
|
editor, etc.
|
|
|
|
The `Editor` holds the global state: all the open documents, a tree
|
|
representation of all the view splits, the configuration, and a registry of
|
|
language servers. To open or close files, interact with the editor.
|
|
|
|
## LSP
|
|
|
|
A language server protocol client.
|
|
|
|
## Term
|
|
|
|
The terminal frontend.
|
|
|
|
The `main` function sets up a new `Application` that runs the event loop.
|
|
|
|
`commands.rs` is probably the most interesting file. It contains all commands
|
|
(actions tied to keybindings).
|
|
|
|
`keymap.rs` links commands to key combinations.
|
|
|
|
|
|
## TUI / Term
|
|
|
|
TODO: document Component and rendering related stuff
|