[NTG-context] catch % in gsub("%", "\\letterpercent")

[Wolfgang Schuster]

Pablo Rodriguez schrieb am 27.08.2020 um 19:16:
> On 8/27/20 6:16 PM, Wolfgang Schuster wrote:
>> Pablo Rodriguez schrieb am 27.08.2020 um 17:56:
>>> [...]
>>>     \startxmlsetups xml:special
>>>       \startitem
>>>       \cldcontext{string.gsub([[\xmlraw{#1}{.}]], "%%",
>>>          "\\letterpercent")}
>>>       \stopitem
>>>     \stopxmlsetups
>> [...]
>> and to escape special characters you can use context.escape()
> Many thanks for your reply, Wolfgang.
>
> I’m afraid that I need to keep $ in order to get some formulas:
>
> \cldcontext{(string.gsub([[\xmlraw{#1}{.}]],
>    '<span class="'..'math inline'..'">', '$'):gsub("</span>",
>    "\\ifmmode $\\fi"))}}
>
> Actually this is way more complex, but I need to catch % and have to
> substitution above.

You have to replace %% with \letterpercent\letterpercent because you're 
still playing with TeX rules.

\startxmlsetups xml:special
     \startitem
\cldcontext{string.gsub("\xmlraw{#1}{.}","\letterpercent\letterpercent","\\letterpercent{}")}
     \stopitem
\stopxmlsetups

To avoid these limitations create a new Lua function and call only this 
function in the setup:

\startluacode

moduledata = moduledata or { }

function moduledata.special(str)
     return string.gsub(str,"%%","\\letterpercent{}")
end

\stopluacode

\startxmlsetups xml:special
     \startitem
     \cldcontext{moduledata.special([[\xmlraw{#1}{.}]])}
     \stopitem
\stopxmlsetups

Wolfgang