[NTG-context] Iterate over color scheme in ConTeXt/Lua

[Hans Hagen]

On 7/12/2020 11:54 PM, Jairo A. del Rio wrote:
> El dom., 12 de jul. de 2020 a la(s) 16:20, Hans Hagen (j.hagen at xs4all.nl 
> <mailto:j.hagen at xs4all.nl>) escribió:
> 
>     You get a list of defined color names in 'xwi' with:
> 
>          attributes.colors.setlist("xwi")
> 
> Nice, it works! I note the first method only works when \usecolors[xwi] 
> is present; otherwise, it prints an interesting "themaintextcolor".
> 
>     Here is a nostalgic mkii accessor for such a list (color support is a
>     real old feature and conceptually hasn't changed that much):
> 
>         \def\WhateverActionIWant#1{#1\par}
> 
>         \settrue\collectcolorsinlist \setupcolor[xwi]
> 
>         \processcommacommand[\colorlist]\WhateverActionIWant
> 
>     but you probably don't want to catch up on that.
> 
> 
> It doesn't work in Mark IV (\colorlist is undefined). Maybe I'm too 
> young, but Mark II was already frozen when I was a teenager, so I'm not 
> sure I want to try it now. Thanks, Hans!
It's low level mkii, never meant for usage outside core code (in this 
case in mkii it is used for typesetting color overviews); mkiv still has 
the same high level commands but different low level ... nothing to 
worry about. The only high level commands that were dropped in mkiv were 
those dealing with obsolete technologies, encodings and such)

Hans

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