deci

README

deci

deci is a terminal text editor like nano.

Quickstart

Install deci by downloading the pre-built binary for your platform from the releases page. If you have Go installed, you can also build from source using this command:

go install github.com/ethmarks/deci@latest

Once you have deci installed, you can run it in your terminal using the deci command followed by the filepath you want to edit (if it doesn't exist, deci will create it when you save). You can also run deci without a filepath if you want, and it'll default to deci_out.txt.

deci myfile.txt

Once you have deci opened, you can just edit your file like in a normal text editor. A list of available keybinds is displayed at the bottom of the screen, and you can press ctrl+h to open the help screen. Press ctrl+o to save your file.

Features

• Integrated Markdown previewing with Glamour
• Undo/redo buffer
• Cursor movement modeled on Zed and VS Code
• TUI components styled with Lipgloss
• Customizable cursor shape and preview theme

Keybinds

deci has unique behavior for 112 keybinds in total.

Basic keybinds that every editor has but which still required a lot of code to implement:

• Typeable characters like "a" and "1" (94 in total): inserts the character at the cursor and moves the cursor right
• enter: splits the current line and moves the right half to a new line (which has the effect of creating a new line if the cursor is at the end of a line) and moves the cursor to the start of the next line.
• backspace: if the cursor is not at the start of a line, removes the character to the left of the cursor and moves the cursor left. If it is at the start of a line, it merges the current line with the previous line (which has the effect of removing it if the current line is blank) and moves the cursor up and to the end of the line
• delete: if the cursor is not at the end of a line, removes the character to the right of the cursor. If the cursor is at the end of a line, it merges the next line with the current line
• tab: inserts 4 spaces
• ctrl+z: reverts to the previous editor state
• ctrl+y: does the opposite of ctrl+z

Cursor movement keybinds, which every editor supports, but were so complicated that they get their own category:

I modeled these behaviors by observing how the IDE that I use (Zed) handles cursor movement. I've also done some testing in VS Code, and it behaves the same as far as I can tell.

• up: if the cursor is not on the first line, moves the cursor up one line and either to the end of the current line or the last x position, whichever is smaller. If the cursor is on the first line, moves the cursor to the start of the line
• down: if the cursor is not on the last line, moves the cursor down one line and either to the end of the current line or the last x position, whichever is smaller. If the cursor is on the last line, moves the cursor to the end of the line
• left: if the cursor is not at the start of the line, moves the cursor left. If the cursor is at the start of the line, moves the cursor up and to the end of the previous line
• right: if the cursor is not at the end of the line, moves the cursor right. If the cursor is at the end of the line, moves the cursor down and to the start of the line
• ctrl+left: moves left until either it reaches the start of the line or it reaches a character that isn't a delimiter (like a space or a punctuation mark), then continues moving left until it reaches a character that is a delimiter
• ctrl+right: moves right until either it reaches the end of the line or it reaches a delimiter, then continues moving right until it reaches a character that isn't a delimiter

Special keybinds:

• ctrl+c: closes deci without saving
• ctrl+o: writes the editor content out to a file
• ctrl+h: toggles the help screen
• ctrl+p: toggles the Markdown preview screen
• alt+p: changes the Markdown preview theme
• alt+c: changes the cursor shape

Building from Source

(requires Go 1.21+)

go install github.com/ethmarks/deci@latest

Etymology

Deci is the Metric prefix for 10^-1, like how Nano is the prefix for 10^-9.

deci	nano
pretty small	tiny
not well known	extremely common

Acknowledgements

• Thanks to the Charm team for making:
  • Bubble Tea, which I used as the TUI framework
  • Lipgloss, which I used to style text
  • Glamour, which I used for the Markdown preview.
• Thanks to Jonathon for making the Colossal font, which I used for the ASCII art in the help screen.
• Thanks to Hunter WB for making AnyASCII, which I used to sanitize the file inputs.
• Thanks to the Go team for making the Go Tour and to Sonia Keys for writing Learn Go in Y Minutes, both of which are super helpful resources that I used to learn Go for this project.

License

This project is under an MIT License. See LICENSE for more information.