Tab indentions on different platforms?

[Thorsten Kampe]

* Ben Finney (Sun, 30 Dec 2007 15:36:12 +1100)
> Steven D'Aprano <steve at REMOVE-THIS-cybersource.com.au> writes:
> > On Sat, 29 Dec 2007 15:29:25 +0000, Thorsten Kampe wrote:
> > > I'd personally go for spaces because:
> > > 
> > > 1. I don't like things I cannot see (control characters)
> > 
> > You can see spaces but not tabs? Your editor is pretty weird. In all
> > the editors I've every used, both spaces and tabs show up as empty
> > white space. (Or coloured space if I set the editor to use a
> > coloured background.)
> 
> Though Thorsten could have been clearer, "thing that is not a space
> character but shows up as white space" is a near-enough approximation
> of "thing I cannot see".
> 
> > > 2. I never had problems with spaces but plenty with tabs
> > 
> > Periodically, I ask on this list what problems people have with
> > tabs. (I'm fully aware that mixing tabs and spaces is a Bad Thing.)
> > I've had little luck getting any answer except "Tabs are bad,
> > m'kay?".
> 
> Posit: White space is most often achieved by the user inserting a
> sequence of space characters (U+0020).
> 
> Posit: Tab characters (U+0009) are, in a majority of environments,
> rendered visually indistinguishable from a sequence of space
> characters.
> 
> Corollary: most readers will, when seeing a stretch of white space on
> a line, default to assuming that it represents a sequence of space
> (U+0020) characters.
> 
> Corollary: So when a file containing either spaces or tabs is edited
> in such an environment, the common way chosen by the user to get to
> the same indentation level as existing lines is to prepend space
> characters (using the spacebar or the Tab key or whatever facility the
> editor provides) until the indentation lines up visually --
> remembering the caveat that tabs and space-sequences are visually
> indistinguishable in many environments.
> 
> Argument: The user will get an unexpected result when they do the
> obvious thing (prepend space characters) in a tabs-only file. With
> existing spaces-only files, the obvious way to get matching
> indentation gives the expected result.
> 
> Conclusion: Thus, using tabs-only is inferior to using spaces-only for
> indentation, because it violates the Principle of Least Astonishment
> <URL:http://en.wikipedia.org/wiki/Principle_of_least_astonishment>.

Man, how did you know what I wanted to say (but failed to to express) 
:-) ? Anyway: the consequence of your well done argumentation is that 
someone editing Python code has to use a specialised editor to prevent 
screwing up tab indented code - and that's bad.

Thorsten