Parinfer for Sublime Text

A Parinfer package for Sublime Text.

What is Parinfer?

Parinfer is a text editing mode that can infer Lisp code structure from indentation (and vice versa). A detailed explanation of Parinfer can be found here.

Put simply: the goal of Parinfer is to make it so you never have to think about “balancing your parens” when writing or editing Lisp code. Just indent your code as normal and Parinfer will infer the intended paren structure.

Installation

Package Control

If you have Package Control installed, you can easily install the Parinfer package:

1. In Sublime Text, open the Command Palette by typing Ctrl+Shift+p (Cmd+Shift+p on Mac)
2. Type install and select Package Control: Install Package
3. A text prompt should appear shortly after Package Control loads a list of packages from the Internet.
4. Type parinfer and press Enter
5. That's it! Parinfer is now installed.

Linux / OSX

You can symlink the the parinfer repo to the Sublime Text Packages directory.

cd ~
git clone git@github.com:oakmac/sublime-text-parinfer.git
ln -s ~/sublime-text-parinfer ~/Library/Application\ Support/Sublime\ Text\ 2/Packages/Parinfer

Windows

cd %APPDATA%\Sublime Text 2\Packages
git clone https://github.com/oakmac/sublime-text-parinfer.git Parinfer

Usage

File Extensions

Once the package has been installed, it will automatically load in the background when you open Sublime Text and watch for file extensions found in a config file. The default file extensions are: .clj .cljs .cljc .lfe .rkt

You can edit these file extensions by going to Preferences –> Package Settings –> Parinfer –> Settings - Default

Opening a File

When a file with a recognized extension is first opened, Parinfer runs Paren Mode on the entire file and one of three things will happen (in order of likelihood):

• The file was unchanged. You will be automatically dropped into Indent Mode. This is the most likely scenario once you start using Parinfer regularly.
• Paren Mode changed the file. The buffer will receive the changes and you will be dropped into Indent Mode. This is most likely to happen when you first start using Parinfer on an existing file.
• Paren Mode failed. This is almost certainly caused by having unbalanced parens in your file (ie: it will not compile). The text will not be changed and you will be dropped into Paren Mode in order to fix the problem.

Running Paren Mode is a necessary first step before Indent Mode can be safely turned on. See Fixing existing files for more information.

Please be aware that - depending on the indentation and formatting in your Lisp files - this initial processing may result in a large diff the first time it happens. Once you start using Indent Mode regularly, this initial processing is unlikely to result in a large diff (or any diff at all). You may even discover that applying Paren Mode to a file can result in catching very hard-to-find bugs in your existing code! As usual, developers are responsible for reviewing their diffs before a code commit :)

Hotkeys and Status Bar

The status bar will indicate which mode you are in or show nothing if Parinfer is turned off.

Future Features

More options and configuration settings are planned for future releases. Browse the issues for an idea of future features. Create a new issue if you can think of a useful feature :)

Known Limitations

This extension uses a hack for performance reasons that may act oddly in certain circumstances. It assumes that an open paren followed by an alpha character - ie: regex ^\([a-zA-Z] - at the start of a line is the beginning of a new “parent expression” and tells the Parinfer algorithm to start analyzing from there until the next line that matches the same regex. Most of the time this is probably a correct assumption, but might break inside multi-line strings or other non-standard circumstances. This is tracked at Issue #23; please add to that if you experience problems.

License

ISC license