/nimrun

Enables use of the compiled nim language as a unix scripting language, "#!"/shebang-style

Primary LanguageNim

nimrun

This is a shebang compatibility wrapper for the nim language. It is licensed under the same license as nim itself, in the hopes that it will one day (with improvements) be shipped along with nim, so that users can rely on nim scripts working so long as nim is installed.

Installing

Install nimble, and ensure its path is set up correctly (if you can run nimble, it probably is).

Then, it should suffice to run:

nimble install nimrun

Usage

Simply add the following first line to a single-file nim program:

#!/usr/bin/env nimrun

Then make the file executable with:

chmod +x your_script(.nim)

Note: as mentioned in the To Do section below, importing from external package dependencies (aside from the nim standard library) isn't (yet?) supported. The entire standard library should be available to import though.

Features

  • This does NOT need a .nim extension on your script file, so that your nim script can be used just like any other executable, regardless of what language it was written in. What's the point of naming the interpreter on the shebang line, if you're going to use an extension? File extensions are a DOS thing anyway.

  • Does not pollute your working directory or the script directory with binaries or cache files. Builds everything in a temporary directory, and executes it from there, whilst maintaining the current working directory as the relative location in which data files are found, etc.

  • This also preserves your filenames and workflows, even if you decide to use a full nim project (or some other language) later (or earlier).

How it works

  • Takes a single argument, the nim script.

  • Builds a nimrod project for it in a temporary directory

  • Compiles the project, saving all compiler output. Only if the compile fails is the compiler output shown.

  • Runs the executable with any remaining arguments

  • Removes the temporary directory

Contributing

Pull requests welcome! Especially for anything in the To Do section.

To do

  • Caching. Nim (and nimble) compile quickly, but it's a bit wasteful without caching, regardless.

  • In future, I might add support for parsing the imports and includes, and including them in the build, giving access to all of the nimble packages from scripts.

Authors