The C language is purely functional

http://conal.net/blog/posts/the-c-language-is-purely-functional/

by beza1e1 • 17 years ago

50 12 17 years ago

ajross• 17 years ago

Cute. There's actually a much more pedestrian point hidden in there, which is that cpp really is an extraordinarily expressive (if hideously clunky) environment, and you can do all sorts of good things with macros if you're willing to learn the tricks.

It's really sad that a bunch of people who never did learn the tricks ended up declaring macros as "bad" by fiat, to the extent that newer languages have had to invent less expressive versions (C++) or omit the facility entirely (Java). These days, it's almost a lost art.

_cbsz• 17 years ago

Well, cpp isn't Turing complete, assuming you only run it once: http://www.ioccc.org/2001/herrmann1.hint

eru• 17 years ago

And C++'s templates are Lambda-Calculus isomorph. (I.e. Turing complete for you imperative programmers. ;o)

russell• 17 years ago

Actually, it was a bunch of people who thought that the rest of us were not competent enough to use them without shooting ourselves in the foot, head, or other parts of our anatomy. (James Gosling are you listening?)

I used macros to great effect to create constant data structures for such things as keyword tables in parsers. The art of programming has advanced a long ways since the early days of C. I think the badness of macros is more a function of those times than inherent problems with macros themselves.

burke• 17 years ago

"...without shooting ourselves in the foot, head, or other parts of our anatomy."

I hear macros are useful for shooting yourself in the gun.

jmillikin• 17 years ago

CPP can be used with Java, since it's completely independent of the "real" underlying language. There's also several native Java preprocessors available.

stcredzero• 17 years ago

Not that again! Someone comes up with some reason to say that C is really Functional about every one and a half years.

magv• 17 years ago

The article wasn't really about C at all.

The author was making a joke about how Haskell uses monads to remain pure.

"cpp" is Haskell, "C" is the way IO monad is used.

conal• 17 years ago

Right. You got it.

dagheti• 17 years ago

Isn't it important though how good CPP is at being Haskell, and how good IO is at being C?

This seems to come back to that original Scala-is-not-functional article, which seems to argue that it isn't features or purity that makes a language "functional" or not, it's how good the language is at working with that style.

dimitar• 17 years ago

Kernighan of K&R didn't invent C. Only the "R", Ritchie did. They wrote a good book together thought.

jlouis• 17 years ago

Corollary: There are no C and C++ programmers. Only CPP programmers using C and C++ for monadic computations :)

The C language is purely functional

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