[rfc-i] sourcecode indentation

[pkyzivat at alum.mit.edu (Paul Kyzivat)]

On 2/13/16 4:40 PM, Brian E Carpenter wrote:
> On 14/02/2016 09:56, Paul Hoffman wrote:
>> On 12 Feb 2016, at 15:52, HANSEN, TONY L wrote:
>>
>>> A better example of outdent would be
>>>
>>> <sourcecode indent="-4">
>>>   foo
>>>     bar
>>>       baz
>>> </sourcecode>
>>>
>>> which would generate:
>>>
>>> <pre class="sourcecode">
>>> foo
>>> bar
>>>   baz
>>> </pre>
>>>
>>> in the HTML format.
>>>
>>> A more common variation might be where the input is coming from elsewhere and you have no control over the indentation used
>>> there:
>>>
>>> <sourcecode indent="-4" src="http://URL to the source code"/>
>>>   or
>>>
>>> <sourcecode indent="16" src="http://URL to the source code"/>
>>>
>>> The use case for this is very specific, but probably not something that would get used often.
>>>
>>> If you think you would find it useful, please speak up.
>>
>> I will speak up against this idea. For sourcecode where indentation is important, seeing an example at the left margin might
>> cause the reader to think that the code is in fact not indented. Your example above is a classic one: someone seeing that text
>> would assume that "foo" and "bar" are at the same level when they are not. I would prefer not to have the RFC format have a
>> display hinting mechanism that could be used to make examples harder to interpret.
>
> It's worse than that. In Python, it can invalidate the example completely.
>
> if whatever:
>      this
> that
>
> is very different from
>
> if whatever:
>      this
>      that
>
> but indent="-4" would reduce them both to
>
> if whatever:
> this
> that
>
> which is invalid syntax. It's a dangerous toy, in other words.

Agreed that is dangerous. But negative indent could be OK if it just 
generates an error if there isn't sufficient whitespace to do the 
outdent completely.

But what does negative indent do if there are tabs at the beginning of 
the text?

	Thanks,
	Paul