[xquery-talk] Using functions in replacement argument with fn:replace()?

[David Sewell]

I may be trying inappropriately to get Perl functionality out of the
XPath 2.0 replace() function, but I'm wondering whether according to the
specs it should be possible to pass backreferences to a function in the
replacement pattern.

I can successfully do this with expected output:

   replace("abc", ".", "$0")  => "abc"

This also gives the expected output (run in both Saxon 8.6 and MarkLogic
Server, ditto for the rest of the examples):

   replace("abc", ".", upper-case("x"))  => "XXX"

but this gives unexpected output:

   replace("abc", ".", upper-case("$0")) => "abc"  [???!!!]

and this produces a run-time error:

   replace("abc", ".", upper-case($0))

Using a different function,

  replace("123", "2", string(number("2") * 2))  => "143"

but

  replace("123", "2", string(number("$0") * 2)) => 1NaN3

I'm not clear from the W3C XPath 2.0 documentation whether the
replacement argument of fn:replace() is supposed to be a literal
xs:string, or whether any expression evaluating to a string is
permissible.

DS


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David Sewell, Editorial and Technical Manager
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