If you’re creating a programming language, here’s what I think you should have:

• Error messages with source code locations, snippets and explanations

• A language server

• A go-to documention source that most libraries use

• A linter and formatter

• A new project generator

• An online playground

• A way to manage different versions of the language

• A C interop

• A package manager

• A build tool that works with packages

• A nice selection of libraries, either bundled with the language or in the ecosystem that handle:

  • Data structures
  • Serialization
  • Web servers
  • GUIs
  • Databases
  • Authentication
  • Error handling
  • Regexes
  • Cryptography
  • Testing

• A way to handle errors gracefully and without too much boilerplate.

• A beginner’s guide. Ideally one that is not just a list of language features.

• Searchable documentation.

• Online spaces where people can ask for help like Discord, reddit, etc.

• A way to handle uninitialized values. Ideally type safe.

Caveats and Explanations

Of course, creating all of these things is far beyond the abilities of a single person. Don’t feel bad if you can’t do it all. It requires a significant amount of investment.

And of course, this is all my opinion, not some ordained list of requirements. Feel free to disagree. There’s also a bunch of stuff I probably missed.

With some of these, people may push back and claim these are optional or even undesirable features (package management, typesafe null). I’d disagree. Often times this opinion that these tools are not necessary comes out of particular situations, whether that’s operating in a company-wide monorepo, a tendency to write code completely from scratch, or simply idiosyncratic ideological preferences. For a language to extend beyond those who are in these particular situations, it should provide these features.

In a sense this is a self fulfilling prophecy, because if a language neglects or dismisses a user’s needs, the user will not join that language community. What’s left is a community that is formed of the people who do not have these needs and therefore see no reason for them to be added.

What amazes me about this list is the paucity of languages that fulfill these requirements. How many languages have a standard site for documentation? How many of them make it easy to search the language documentation? Maybe it’s entitled to expect so much of projects that are essentially volunteer efforts, but I strongly believe these aspects would provide an incredible return on investment.

P.S. This list may seem overtly pro-Rust in that it cites various features that the Rust ecosystem has. That is true, but I will note that Rust still needs improvement as well: docs.rs, while great for API documentation, is not great for the walkthrough, linear based documentation that I find useful. Rust also lacks good GUI and authentication libraries. That said, I will admit that I am looking at this from a very biased place. I’d love to see what people of other language communities have as their language checklist.