Re: [Haskell-cafe] Comment Syntax

Roman Cheplyaka writes:

* Andrew Coppin [2011-06-03 18:12:04+0100]

...

On 03/06/2011 05:02 PM, Albert Y. C. Lai wrote:

...

I propose that only {- -} is comment; that is, -- is an operator token and not a marker of comments.

I'm curious to know why anybody thought that "--" was a good comment marker in the first place. (I'm curious because Haskell isn't the only language to have made this strange choice.)

It is, for my taste, a good comment marker, because of its resemblance to a dash. It makes the code look like real text:

let y = x + 1 -- increment x

And when the language was first defined, there was no real dash available for this purpose. Nowadays we could use the unicode em dash (U+2014, "—" if it survices nntp), and free up -- for other purposes. Of course, its hard to predict what effect this would have when people didn't know how to enter it, and although it's quite distinctive in proportional fonts, the difference between - and — in monospace fonts is much harder to see. -- Jón Fairbairn Jon.Fairbairn@cl.cam.ac.uk http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html (updated 2010-09-14)