Runic.jl

A code formatter with rules set in stone.

Installation

using Pkg
Pkg.add("Runic")

Usage

The main interface to Runic is the command line interface (CLI) through the main function invoked with the -m flag. See the output of julia -m Runic --help for details:

[!NOTE] The -m command line flag is only available in Julia 1.12 and later. In earlier versions you have to invoke the main function explicitly, for example:

julia -e 'using Runic; exit(Runic.main(ARGS))' -- <args>

$ julia-master -m Runic --help
NAME
       Runic.main - format Julia source code

SYNOPSIS
       julia -m Runic [<options>] <path>...

DESCRIPTION
       `Runic.main` (typically invoked as `julia -m Runic`) formats Julia source
       code using the Runic.jl formatter.

OPTIONS
       <path>...
           Input path(s) (files and/or directories) to process. For directories,
           all files (recursively) with the '*.jl' suffix are used as input files.
           If path is `-` input is read from stdin.

       -c, --check
           Do not write output and exit with a non-zero code if the input is not
           formatted correctly.

       -d, --diff
           Print the diff between the input and formatted output to stderr.
           Requires `git` or `diff` to be installed.

       --fail-fast
           Exit immediately after the first error. Only applicable when formatting
           multiple files in the same invocation.

       --help
           Print this message.

       -i, --inplace
           Edit files in place. This option is required when passing multiple input
           paths.

       -o, --output <file>
           Output file to write formatted code to. If the specified file is `-`
           output is written to stdout. This option can not be used together with
           multiple input paths.

In addition to the CLI there is also the two function Runic.format_file and Runic.format_string. See their respective docstrings for details.

Formatting specification

This is a list of the rules and formatting transformations performed by Runic:

• No trailing whitespace
• Normalized line endings (\r\n -> \n) (TODO: Is this bad on Windows with Git's autocrlf? gofmt does it...)
• Hex/octal/binary literals are padded with zeroes to better highlight the resulting UInt type
• Floating point literals are normalized to always have an integral and fractional part. E-exponents are normalized to e-exponents. Unnecessary trailing/leading zeros from integral, fractional, and exponent parts are removed.