Re: Quoted atoms are no longer operators

Jan Wielemaker:
>> On 22-11-13 16:36, Jan Wielemaker wrote:
>>>    - Quoted atoms are no longer operators.
>>
>> also about this change, I'd like to know: is there a (very) good reason?
>> If not, I'd like to add my voice to what Richard said [1]: this is a bad
>> idea, making e.g. operators with spaces in them impossible.
>
>True. I've never seen them in the wild though. Putting white space
>inside identifiers is a pretty bad idea anyway because many reformatting
>tools (or editor commands) can silently change this, breaking your code
>and anyway, the difference between 'a<space>b' and 'a<tab>b' may be
>invisible and the difference between 'a b' and 'a  b' is poorly visible,
>in particular when using variable pitch fonts.

Your statement needs a clarification.  ISO does not define 'a<tab>b'
as valid syntax.  Nor any other layout except the space. For exactly
the reason you give.

However, on a very formal basis, you can decare this as an extension
due to 5.5.1 Syntax.  Many systems do this, the notable exceptions
are GNU and SICStus.

http://www.complang.tuwien.ac.at/ulrich/iso-prolog/conformity_assessment#5

So we have here the same pattern again:

1mo: non-adherence to the standard

2do: blaming the standard for something it forbids, deriding the
"tiny" issues the standard deals with.

3tio: introduction of incompatibile features to heal the disease
created in 1mo.

>Richard's A '\uXXXX' B argument makes a little more sense. On the other
>hand, if you want it this ugly, '\uXXXX'(A,B) is just as good (or should
>I say ugly).

A better criterion is conformance/nonconformance. The ISO syntax for
above is '\xXXXX\', btw.

>This is a quite isolated issue.

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