while trying the "Getting the last page of a Booklet" example on the
wiki page https://wiki.contextgarden.net/Imposition
context complains:
open source > level 1, order 2, name './imposition_test2.tex'
! Control sequence expected instead of undefined.
<argument>
\v!nextquadruple
<macro> \installpagebreakhandler
#1#2->\defcsname \??pagebreakmethod #1
\endcsname {#2}
\fi}
You injected something that confused the parser, maybe by using some Lua
call.
this is the example code:
8<---
\unprotect
\startvariables all
nextquadruple: nextquadruple
\stopvariables
\installpagebreakhandler \v!nextquadruple
{\ifdoublesided
\!!counta\realpageno
\!!countb\realpageno
\advance\!!counta 4
\divide\!!counta 4
\multiply\!!counta 4
\advance\!!countb 1
\advance\!!counta-\!!countb
\executepagebreakhandler\v!yes
\dorecurse\!!counta{\executepagebreakhandler\v!empty}%
\fi}
\protect
\setuppapersize[A5][A4]
\setuparranging[2UP,rotated,doublesided]
\setuppagenumbering[alternative=doublesided]
\starttext
\subject{Front Cover}
\dorecurse{10}{\input tufte \par}
\page[nextquadruple]
Back Cover
\stoptext
--->8
most likely there is a reason for the error...