Re: [office-formula] 6.3.7 Infix Operator "<>"

[Patrick Durusau <patrick@durusau.net>]

David,

David A. Wheeler wrote:
>> Under Semantics we say:
>>
>>     
>>> Note that if either Left and Right are an error, the result is an 
>>> error; this operator cannot be used to determine if two errors are the 
>>> same kind of error.
>>>
>>>       
>> Instead of None for constraints, shouldn't the possible values of Left 
>> or Right exclude an error?
>>
>> Then if the general rule is violation of constraint is an error then we 
>> can drop this sentence altogether.
>>     
>
> This sentence does not, and is not intended, to
> DEFINE the semantic. Instead, it clarifies
> an implication of the semantics defined above.  That's why it
> starts with the text "Note that....".
>
> The reason this note was added was that users might
> think it was okay to compare error values using <>, e.g.,
> "NA() <> 1/0", which is NOT what <> is good for
> (it would return an Error, not TRUE() or FALSE()).
>
> Is it not clear that this text is a note?  I realize that you're
> not big on explanatory text, but sometimes implications really
> need to be clarified in the spec to make sure people don't do the wrong thing.
>
>   
Oh, when you use the prose "Note that ...." you mean this as 
non-normative text? OK. No, that wasn't clear that you meant for it to 
be non-normative.

But why is there a need to clarify the semantic if the standard defines 
the inputs to operator to exclude those of type error? (I am assuming 
there is an error type. I have seen it referenced. But also spoken of as 
"an error" which may or may not be the same thing.)

BTW, is the violation of a constraint always an error (or of type error)?

Hope you are having a great day!

Patrick

-- 
Patrick Durusau
patrick@durusau.net
Chair, V1 - US TAG to JTC 1/SC 34
Convener, JTC 1/SC 34/WG 3 (Topic Maps)
Editor, OpenDocument Format TC (OASIS), Project Editor ISO/IEC 26300
Co-Editor, ISO/IEC 13250-1, 13250-5 (Topic Maps)