Re: Question on translate() function

Great..
I have seen expressions like :
translate($xxx, 'ABCDE','x');
which is to say, replace ABCDE with x .. this also works fine
is this not valid?

or should we do ..translate($xxx, 'ABCDE','xxxxx');

dak

On Mon, Sep 25, 2017 at 6:00 PM, Liam R. E. Quin liam@xxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
> On Mon, 2017-09-25 at 17:42 +0000, Syd Bauman s.bauman@xxxxxxxxxxxxxxxx
> wrote:
>>
>> I have always presumed that translate() is faster than replace().[1]
>
> I'd say, use whichever is clearer, braver, more noble. Take pity on
> your future self trying to understand replace("[{]\\\$[()][}]", "#",
> "g")...
>
> As for which is faster, it depends not only (as the inestimable Dr Kay
> has expressed) upon the quality of the optimizer but for some
> implementations the quality of the underlying code. Unfortunately there
> are enough differences between XSLT and Perl regular expressions that
> using libpcre has become difficult, as that library gets extensive
> optimization outside of our universe and then returns through alternate
> dimensions to dazzle us :)
>
>> But I can't help it, sometimes -- I'd really like to know if
>> translate() is significantly more efficient (computationally) than
>> replace() or not.
>
> There's no inherent reason why
>   translate("abc", "ddd")
> should be faster or slower than
>   replace("[abc]", "d", "g")
> once the parsing has been done; however, the work to recognize these
> two cases may be easier for translate().
>
> There are implementations that are faster than a freshly-oiled cow at
> recognizing regular expression character classes, so if your input
> string is, say, 100MBytes long, you might well be able to measure the
> difference. In ASCII days there were implementations that used a bit
> mask, and then you compare each input character (or four characters at
> a time, say, using a wider mask) with the or'd mask and only do the
> more expensive computation when needed. So an implementation using a
> heavily optimized regular expression library might go faster with
> replace() than translate(), because the XSLT/XPath/XQuery implementor
> of translate() might not have done that sort of optimization.
>
> Liam
>
> --
> Liam Quin, W3C, http://www.w3.org/People/Quin/
> Staff contact for Verifiable Claims WG, SVG WG, XQuery WG
>
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