Are comments necessary for a programming language?

I am not sure I agree with the "Have" in the statement "Removing the ability to comment from a programming language meant I HAVE to write literate code, no exceptions", since it is not as if all code is documented. My guess is that most people would write unreadable code.

More to the point, I personally do not believe in the reality of the self-explanatory program or API in the practical world.

My experience from manually analyzing the documentation of entire APIs for my dissertation suggests that all too often you would have to carry more information than you could convey in the signature alone. If you eliminate interface comments from your language, what are the alternatives? No documentation is not an option. External documentation is less likely to be read.

As for internal documentation, I can see your point in wanting to reduce documentation to convince people to write better. However, comments serve many collaboration and coordination purposes and are meant to raise awareness of things. By banishing these details to extenral locations, you are reducing the chances that they come to a future reader's awareness, unless your tooling is great.

Ugh, not being able to quickly comment out a line (or lines) during testing sounds annoying to me, especially when scripting.

In general comments are a wart that indicates poor design, especially long rambling comments where its clear the developer didn't have a clue what the heck they where doing and tried to make up for it by writing a comment.

Places where comments are useful:

• Leaving a ticket number next to a fix so future programmers can understand business requirements
• Explaining a particularly tricky hack
• Commentary on business logic for a piece of code
• Terse descriptions in API docs so a third-party can use your API

In all circumstances programmers should endeavor to write code that is descriptive and NOT write comments that describe poorly written code. That being said I think there are plenty of valid reasons that languages should and must support comments.

Do not comment WHAT you are doing, but WHY you are doing it.

The WHAT is taken care of by clean, readable and simple code with proper choice of variable names to support it. Comments show a higher level structure to the code that can't be (or is hard to) show by the code itself.