Re: [xml-dev] XPath expression which checks that all commas are escaped

[Dimitre Novatchev <dnovatchev@gmail.com>]

> not(contains(replace(., '\\,', ''), ','))

And, of course:

not(matches(., '[^\\],'))


Cheers,
Dimitre

On Fri, Nov 3, 2017 at 12:14 PM, Dimitre Novatchev <dnovatchev@gmail.com> wrote:
> not(contains(replace(., '\\,', ''), ','))
>
> On Fri, Nov 3, 2017 at 11:40 AM, Costello, Roger L. <costello@mitre.org> wrote:
>> Hi Folks,
>>
>> Do you deal with Request for Comments (RFCs)? Then the following might come
>> in handy someday.
>>
>> Note: Thanks to Martin Honnen for helping me with the XPath expression
>> (below).
>>
>> Some RFCs (e.g., vCard) have this rule:
>>
>>
>>
>>                 Each comma in a value must be escaped with a backslash.
>>
>>
>>
>> Examples:
>>
>>
>>
>> This value is good:
>>
>>
>>
>> A\, B
>>
>>
>>
>> This value is bad:
>>
>>
>>
>> A, B
>>
>>
>>
>> This value is also bad, because one comma is escaped but the other is not:
>>
>>
>>
>> A\, B, C
>>
>>
>>
>> Suppose the RFC has an XML representation. Or, you have used something like
>> DFDL to convert the data to XML.
>>
>> Then, this XPath expression checks to see that each comma is properly
>> escaped:
>>
>> every $token in tokenize(., ',')[position() lt last()] satisfies
>> ends-with($token, '\')
>>
>>
>>
>> That XPath expression can be used in Schematron like this:
>>
>> <sch:pattern id="Escaping-Rules">
>>
>>     <sch:rule context="value">
>>
>>         <sch:assert test="every $token in tokenize(., ',')[position() lt
>> last()] satisfies ends-with($token, '\')">
>>             A COMMA character in a value MUST be escaped with
>>             a BACKSLASH character (U+005C).
>>         </sch:assert>
>>
>>     </sch:rule>
>>
>> </sch:pattern>
>
>
>
> --
> Cheers,
> Dimitre Novatchev
> ---------------------------------------
> Truly great madness cannot be achieved without significant intelligence.
> ---------------------------------------
> To invent, you need a good imagination and a pile of junk
> -------------------------------------
> Never fight an inanimate object
> -------------------------------------
> To avoid situations in which you might make mistakes may be the
> biggest mistake of all
> ------------------------------------
> Quality means doing it right when no one is looking.
> -------------------------------------
> You've achieved success in your field when you don't know whether what
> you're doing is work or play
> -------------------------------------
> To achieve the impossible dream, try going to sleep.
> -------------------------------------
> Facts do not cease to exist because they are ignored.
> -------------------------------------
> Typing monkeys will write all Shakespeare's works in 200yrs.Will they
> write all patents, too? :)
> -------------------------------------
> Sanity is madness put to good use.
> -------------------------------------
> I finally figured out the only reason to be alive is to enjoy it.



-- 
Cheers,
Dimitre Novatchev
---------------------------------------
Truly great madness cannot be achieved without significant intelligence.
---------------------------------------
To invent, you need a good imagination and a pile of junk
-------------------------------------
Never fight an inanimate object
-------------------------------------
To avoid situations in which you might make mistakes may be the
biggest mistake of all
------------------------------------
Quality means doing it right when no one is looking.
-------------------------------------
You've achieved success in your field when you don't know whether what
you're doing is work or play
-------------------------------------
To achieve the impossible dream, try going to sleep.
-------------------------------------
Facts do not cease to exist because they are ignored.
-------------------------------------
Typing monkeys will write all Shakespeare's works in 200yrs.Will they
write all patents, too? :)
-------------------------------------
Sanity is madness put to good use.
-------------------------------------
I finally figured out the only reason to be alive is to enjoy it.