[nnq]

> context-dependent grammar makes it possible (and in case of Perl, even very easy) to write WTF code.

Do you really think that a context-dependent grammar will make for easier to understand code? Or more generally, do you really think that a language that is easier to parse is also easier for a human to understand?

...the human brain works very differently from your parser or lexer and code that may be very hard to parse for a computer may be very easy for a human to understand, and in reverse, code that is easy for the computer to parse can be virtually incomprehensible to a human.

If what you say were true, then we would all be using some kind of Lisp, as there's nothing easier to parse, but this is not the current reality. And don't tell me that we aren't because Lisp was inefficient or the AI-winter or anything like that. You can easily express a C-like language in a Lisp style notation. Complicated syntaxes that makes it harder to write parsers tend to be much easier for the human brain to understand, imho. Problems arise when some languages like Perl have rules that are "too relaxed" or "with too many exceptions" and this leads to WTF code.

In fact, looking at the kinds of notations that physicists and mathematicians use (you'd be surprised how "context dependent" mathematical language is, and by "context" I don't even mean lexical context, I actually mean "common set of assumptions held in the minds of most mathematicians about what each notation tends to mean in each context"), I'd say that the human brain is actually aggressively optimized for context-dependent languages!

[mynegation]

Sure you can write incomprehensible context-free grammar, but yes, in my opinion, context free languages tend to be easier to understand or at least understand unambiguously. Natural language (which is obviously very context-dependent if you can even apply this name to a language without formal grammar) is easy to understand but is not a good language for giving instructions to a computer (cue classic "Time flies like bananas").

Interestingly enough, I personally found understanding Lisp, once I got the idea of paradigm, pretty much instantly. I do not think that the reason for us not using Lisp is syntax, but rather a combination of non-traditional paradigm and difference from the mainstream imperative languages. On top of that you do need to keep a lot of context while looking at Lisp program, but this is execution context, not the grammar context.

[nnq]

EDIT: I meant: "Do you really think that a context-independent grammar will make for easier to understand code?"