sim 0.1.0

sim 0.1.0

sim is the next-generation Vim. It shows even what is hidden, it is secure, and it is written from scratch in Rust. The name is short for Secure vIM.

This is the first public release.

Files that other processes rewrite: you read them as fast as possible, fix them, and save them without losing anything. A project's files a few keys away, several of them open at once, and syntax colors that never take the change color's hue.

What makes it different

• Changes from outside are marked. When a file changes on disk while you edit it, sim merges what doesn't conflict with your edits and marks it, word by word, until you've looked at it; ]c goes to the next mark. Where it does conflict, your text stays, marked, and nothing is written over the file: :w! keeps yours and :e! takes the disk's, and each copies the version it gives up into the state directory first.
• Saves that can't lose. Saves are atomic (temp file, fsync, rename, directory fsync) and compare-and-swap: if the file changed since you read it, nothing is overwritten. Unsaved changes are snapshotted every second; after a crash, kill -9 or a closed terminal, reopening the file offers them back as one undo step.
• Hidden things are shown. A character that must not reach the terminal, or that looks like another, is drawn as itself in the alert's block (^X, <U+202E>), and nothing around it can hide it.
• Readable by measurement. Text is 90 Lc and secondary text 60 Lc (APCA), computed from your terminal's background; the one change color stays distinguishable under protan, deutan and tritan color vision; prose wraps with Japanese kinsoku.
• Meaning without color. With NO_COLOR set, or on a terminal that cannot do 8 colors, sim writes no color at all: weight, underline and inverse video say what the colors said.
• Keys your hands already know. The vi grammar, minus vi's accidents: Y yanks to the end of the line, U redoes, search is smartcase, every yank reaches the system clipboard (also through tmux), Ctrl-s saves, q quits, arrows and Home/End work everywhere.

And a place to live in

• A tree of the project (Ctrl-n) that never reorders, with git status, and the five files you are most likely to open next marked with •.
• Several files open at once, each one a complete editor with its own undo, snapshots and saves (Tab, Shift-Tab).
• Find a file (Ctrl-p, or / in the tree) and search the contents of the files as you type (Ctrl-f, with ripgrep if it is on your PATH), in a picker with a preview. A search never writes and never runs code a repository controls.
• Syntax colors in your terminal's own palette, three looks (zl: calm, flat, depth), a mouse that never edits by itself.
• sim --plain: the core alone, with no program of its own run (no git, ripgrep, filter or hook). It is what sim is as root and as the editor of sudoedit.

export EDITOR=sim                     # crontab -e, …
git config --global core.editor sim   # git commit (ZZ commits, :cq aborts)
export SUDO_EDITOR='sim --plain'      # sudoedit

Finding the keys

• A leader and which-key. Space is the leader. Pause after a prefix (Space, g, z, [, ] or an operator) and a small window lists the keys that can come next; keep typing and it is not in the way.
• :help and F1. Every key and command, fuzzy-filtered, with the longer text in a preview: :help tab finds Tab, Shift-Tab and <Space>bp.
• Tabs by letter. <Space>bp puts a letter on each tab and the letter shows that file; <Space>bc closes one the same way (a file with changes stays open, as with :q).
• Hints and counts. The second file you open shows a one-time hint for Tab and Shift-Tab; a search shows [i/n] in the status line while its matches are lit.
• sim --version prints sim 0.1.0; sim --help prints the usage.

Install

brew install efg-technologies/tap/sim     # Homebrew: builds from source

• From source: git clone https://github.com/efg-technologies/sim.git && cd sim && cargo install --locked --path sim.
• The AUR package (sim-editor) and the crates on crates.io (sim-editor, sim-editor-core) follow shortly.

Needs Rust 1.88 or later to build. Runs on Linux and macOS, in any terminal; colors, the kitty keyboard protocol and OSC 52 are used when the terminal offers them (Ghostty, kitty, WezTerm, tmux). git and rg are optional: sim uses them when they are on PATH. sim makes no network connection.

Release asset: sim-0.1.0.tar.gz, the source of tag v0.1.0. sim is distributed as source; the package managers above build it.

What to know

• "More readable than existing editors" is a hypothesis, not a claim: the benchmark that would test it (time and accuracy to find a change) is not built yet. Flat and depth use red and green for changes and set color vision aside; calm is the look for anyone who cannot tell red from green.
• Icons need a Nerd Font. They start on in Ghostty, kitty and WezTerm and off elsewhere, with a hint to turn them on (zi).
• By design sim has no plugins, no config files and no network access; split windows are left to tmux. Its choices live in ~/.local/state/sim (or $XDG_STATE_HOME/sim).
• Everything sim promises, it promises for every file open in it: without an explicit action, nobody's text is lost.

Why each choice was made, with the research it rests on, is in CONCEPT.md; what sim must do is in SPEC.md, where every requirement has an ID and every ID has tests. The full list of changes is in CHANGELOG.md.

Dual-licensed under MIT or Apache-2.0, at your option.