On 3/29/2021 10:54 AM, Jairo A. del Rio wrote:
Hi list! See the following example:
\startluacode
userdata = userdata or {}
--Toy example
--My actual function receives an argument, but the problem remains the same
userdata.myfunction = function()
return
"343327959841638047651959775267761420323" ..
"657838053757849835434002826851807933276" ..
"324327913964298509889902373459201557839" ..
"84828001486412574060553756854137069878601"
end
interfaces.implement{
name = "myfunction",
public = true,
actions =
function ()
context(userdata.myfunction())
end
}
\stopluacode
\def\colorfulnumbers#1{\colored[h=\luaexpr{40*#1},s=1,v=1]{#1}\ }%
\starttext
%It doesn't work
%\handletokens{\myfunction}\with\colorfulnumbers
\expandafter\handletokens\expandafter{\myfunction}\with\colorfulnumbers
\stoptext
As readily seen from my example, I want to color each figure of the
numbers generated by a Lua function. However, the use of \expandafter's
is cumbersome in this case. I don't want to loop over the result in Lua
because I want to be able to apply \handletokens...\with... (or another
macro with a similar purpose) with different macros at the TeX end once
Lua has delivered results. How should I do it in ConTeXt?
In the usual way: different from what you might expect:
\startluacode
userdata = userdata or { }
userdata.myfunction = function()
return
"343327959841638047651959775267761420323" ..
"657838053757849835434002826851807933276" ..
"324327913964298509889902373459201557839" ..
"84828001486412574060553756854137069878601"
end
\stopluacode
\doloopovermatch {.} {\luaexpr{userdata.myfunction()}} {%
\colored[h=\luaexpr{40*#1},s=1,v=1]{#1}\space
}
or let youself surprise by:
\startluacode
userdata = userdata or { }
userdata.myfunction = function()
return [[
343327959841638047651959775267761420323
657838053757849835434002826851807933276
324327913964298509889902373459201557839
84828001486412574060553756854137069878601
]]
end
\stopluacode
\starttext
\doloopovermatch {\letterpercent d} {\luaexpr{userdata.myfunction()}} {%
\colored[h=\luaexpr{40*#1},s=1,v=1]{#1}\space
}
(I think it's even documented somewhere.)
\handletokens is kind of mkii-ish and old fashioned.
Hans
-
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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