2024-07-07 00:33:47 +02:00
|
|
|
---
|
|
|
|
|
title: "Gap Buffer"
|
|
|
|
|
date: 2024-07-06T21:27:19+01:00
|
|
|
|
|
draft: false # I don't care for draft mode, git has branches for that
|
|
|
|
|
description: "As featured in GNU Emacs"
|
|
|
|
|
tags:
|
|
|
|
|
- algorithms
|
|
|
|
|
- data structures
|
|
|
|
|
- python
|
|
|
|
|
categories:
|
|
|
|
|
- programming
|
|
|
|
|
series:
|
|
|
|
|
- Cool algorithms
|
|
|
|
|
favorite: false
|
|
|
|
|
disable_feed: false
|
|
|
|
|
---
|
|
|
|
|
|
|
|
|
|
The [_Gap Buffer_][wiki] is a popular data structure for text editors to
|
|
|
|
|
represent files and editable buffers. The most famous of them probably being
|
|
|
|
|
[GNU Emacs][emacs].
|
|
|
|
|
|
|
|
|
|
[wiki]: https://en.wikipedia.org/wiki/Gap_buffer
|
|
|
|
|
[emacs]: https://www.gnu.org/software/emacs/manual/html_node/elisp/Buffer-Gap.html
|
|
|
|
|
|
|
|
|
|
<!--more-->
|
2024-07-07 00:34:49 +02:00
|
|
|
|
|
|
|
|
## What does it do?
|
|
|
|
|
|
|
|
|
|
A _Gap Buffer_ is simply a list of characters, similar to a normal string, with
|
|
|
|
|
the added twist of splitting it into two side: the prefix and suffix, on either
|
|
|
|
|
side of the cursor. In between them, a gap is left to allow for quick
|
|
|
|
|
insertion at the cursor.
|
|
|
|
|
|
|
|
|
|
Moving the cursor moves the gap around the buffer, the prefix and suffix getting
|
|
|
|
|
shorter/longer as required.
|
