Hi Denis,
I need to process URLs in XML documents differently depending on the target.
Thanks to Hans and Thomas I can now deal with the attributes.
Now I need to prefix certain kind of targets with a certain URL (a web viewer
for IIIF images in this particular case). The prefix contains a #, which, as a
special character seems to cause an error. Adding a double hash seems to work,
but those ## will end up in the link URL. How can I properly escape a single #?
I've already tried using \Ux{23}, but that won't work either.
The duplication of hashes is kind of special. Consider this:
\def\foo#1{#1 test ##}
\def\foo#1{#1 test\def\more##1{(##1)}}
the internal representation of #1 is a reference to parameter 1 while
the ## becomes one # (cc parameter) in the second exmaple followed by a
character 1 (cc other)
then, when tex serializes e.g. in tracing it duplicates the hash (with
cc parameter) so that the user is not confused (an alternative could
have been to indicate a parameter reference differently but changing
that now is no real option - what symbol to use anyway?)
with lua(meta)tex opening up matters this duplication becomes a bit
annoying so i decided to see if it could be avoided in some cases
first i decided to provide an escape, possible because we already have
such mechanism using # (not advertised because it is still experimental)
then i decided to just not duplicate unless we trace
in the lowlevel macro manual there is a section added that goes in more
detail
to come back to the escaping: here is a list:
#I loop iteraor
#P parent loop iterator
#G grandparent loop iterator
#H hash
#S space (ascii 32)
#T tab \t
#L newline \n
#R return \r
#X backslash
considering
#N nbsp
and some more. Keep in mind that #1-#9 #A-#E are in use as parameter
references
but in the case of your url's escaping should not be needed (hopefully)
Hans
ps. all kind of expereimental because it's a bit hairy and we don't want
to loose compatibility (hashes get interpreted in the macro preamble,
macro body, running text, serialization etc)
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Hans Hagen | PRAGMA ADE
Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
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