Clojure with Python syntax, part II

A couple months ago, I posted some thoughts I was having about writing a DSL that would make it possible to write Clojure without the s-expressions, the nesting, and back-and-forth indentation style that is so common in Lisp programs. I said the following would be the goals of the project, if I were to do it:

• Eliminate the Lisp syntax barrier to getting programmers to try Clojure.
• Make Clojure acceptable to universities that want to avoid Lisp syntax.
• Provide a stepping stone so that programmers can learn Clojure concepts, then when they want more control over their language, they can start writing Clojure without giving up any of their existing code.

The post was motivated by my attempts to get others interested in Clojure. I'm a true believer in Clojure - I don't think there's another language that offers anything close to the experience. It's just a well thought out language that was implemented by someone with a lot of programming experience. The meaning of the term "pragmatic" has changed in recent years to mean "excuse for hypocrisy", so I won't say Clojure is pragmatic, but it certainly is a practical approach to functional programming. I think it is the best choice for those learning to program as well as those who want to get work done.

That is why I was disappointed at the way Clojure's syntax, which is quite an improvement on the Lisps that came before, is still viewed as clumsy and hard to read. I've always loved the consistency of Lisp syntax, and have always felt that the advantages of consistency outweigh any of the complaints. Too bad that's not true for everyone.

I've come to accept that humans treat their first experience as the default. Once you've reached puberty, you can forget about speaking a foreign language without an accent, because you will always, to some extent, try to put the new language into the form of the old. An accent is nothing more than pronouncing the new language using the "idiomatic" form of your native tongue.

I see no compelling reason that Lisp syntax should be a barrier to using Clojure. If your "default" is that a language should look like Python, then you should be able to write Clojure in that form. You'd lose the power of macros, but how is that a problem for someone who doesn't know Clojure or any other Lisp? When they're ready to take the leap to start writing macros, they can start working with s-expressions.

I did some searching on Google before my previous post. I had hoped this would already have been done, but I couldn't find anything. Richard Gabriel and Guy Steele even have a section in this paper devoted to alternative Lisp syntax. The problem is that all of those alternatives are ugly, much worse than Scheme or Common Lisp, so it's not at all surprising that none of them took off.

Basically every similar project has the same fatal flaw. They're all trying to be Lisp without parenthesis. In my experience, the objection to Lisp has little to do with parenthesis. Even when you end up with something like this: )))))))), the problem is that you've nested eight things in one statement, usually with varying levels of indentation, so it's not really the eight parens that causes the grumbling. Python, Ruby, or C programmers are unlikely to have eight levels of nesting in their programs.

The thing to realize with alternative Lisp syntax is that you can't save macros or prefix notation. Clojure != macros. Clojure != prefix notation. Clojure does so much so well that there is no reason to fear the loss of macros. I know about languages like Dylan. Dylan is not in any way worthy of comparison with Clojure. As a matter of fact, Clojure with Python syntax wouldn't even be a Lisp anymore, and that's okay, because I don't really care about Lisp. I could still write my Clojure with parens, it wouldn't make any difference how others write theirs, since it would still be Clojure. I can sit in my basement on Saturday night as a hobbyist writing macros, but I'd rather use Clojure all day at the office, even if I'm not using Lisp.

I haven't had time to dig into it as deeply as I'd like. Here's what I have concluded on the basis of my research:

• I don't know anything about writing a DSL, parsing, or code generation.
• I'm an intermediate Clojure user, so I don't yet understand some of the features of the language, and I don't understand most of the language as well as I should.
• I don't use Python much these days (I don't think I've written a line of Python code in the last year). I don't understand what is so readable about Python, it looks the same to me as any other language.
• Nobody would care if I did write it. I could show it to the people I know, but being realistic, few people would use it.

Combining my current time constraints with the huge cost of learning everything I'd have to learn, and comparing with the benefits, I can't justify doing it. I nevertheless think it would be a worthwhile project for someone who has no kids and is looking for a way to kill some time.