Re: [9fans] A new language for Plan 9

[Pietro Gagliardi <pietro10@mac.com>]

On May 1, 2008, at 9:52 PM, Rob Pike wrote:

> Indentation by white space is a very bad idea in my experience.
> Superficially attractive but ultimately very dangerous. I once spent a
> couple of days tracking down a bug caused by a source-to-source code
> tool that broke a major program because the code it was injecting into
> had indented one more space, causing the injecting code to break the
> control flow. It was nearly impossible to track down.
>
This scenario is why I decided to require hard tabs as indents. You
can't use a space. But a space halts the indentation, so the problem
is still there. The next version will just ignore spaces, and treat
the first non-whitespace character as the beginning of a line.

> I have lots of other examples of lesser disasters. As code grows,
> white space indentation becomes ever more problematic. It's a
> maintenance disaster.
>
> Put it this way: It's unwise to make program structure depend on
> invisible characters.
There's a language made entirely of said invisible characters, called
Whitespace. It's esoteric, but it works. And Python, which has the
same style, is a phenomenal success. Whether or not indentation works
relies on the programmer.