2021-10-28 10:19:00

21 files changed, 514 insertions, 9 deletions

diff --git a/tex/context/base/mkii/cont-new.mkii b/tex/context/base/mkii/cont-new.mkii
index cbb77a698..3fac13aaf 100644
--- a/tex/context/base/mkii/cont-new.mkii
+++ b/tex/context/base/mkii/cont-new.mkii
@@ -11,7 +11,7 @@
 %C therefore copyrighted by \PRAGMA. See mreadme.pdf for
 %C details.
 
-\newcontextversion{2021.10.24 21:42}
+\newcontextversion{2021.10.28 10:17}
 
 %D This file is loaded at runtime, thereby providing an
 %D excellent place for hacks, patches, extensions and new
diff --git a/tex/context/base/mkii/context.mkii b/tex/context/base/mkii/context.mkii
index e1a1ec97c..fedf5acb3 100644
--- a/tex/context/base/mkii/context.mkii
+++ b/tex/context/base/mkii/context.mkii
@@ -20,7 +20,7 @@
 %D your styles an modules.
 
 \edef\contextformat {\jobname}
-\edef\contextversion{2021.10.24 21:42}
+\edef\contextversion{2021.10.28 10:17}
 
 %D For those who want to use this:
 
diff --git a/tex/context/base/mkii/mult-ro.mkii b/tex/context/base/mkii/mult-ro.mkii
index 9aede3730..87a4a91c0 100644
--- a/tex/context/base/mkii/mult-ro.mkii
+++ b/tex/context/base/mkii/mult-ro.mkii
@@ -188,6 +188,7 @@
 \setinterfacevariable{enumeration}{enumerare}
 \setinterfacevariable{environment}{mediu}
 \setinterfacevariable{even}{par}
+\setinterfacevariable{explicit}{explicit}
 \setinterfacevariable{export}{export}
 \setinterfacevariable{external}{extern}
 \setinterfacevariable{extremestretch}{extremestretch}
diff --git a/tex/context/base/mkiv/cont-new.mkiv b/tex/context/base/mkiv/cont-new.mkiv
index e5bd908d4..8c12216dd 100644
--- a/tex/context/base/mkiv/cont-new.mkiv
+++ b/tex/context/base/mkiv/cont-new.mkiv
@@ -13,7 +13,7 @@
 
 % \normalend % uncomment this to get the real base runtime
 
-\newcontextversion{2021.10.24 21:42}
+\newcontextversion{2021.10.28 10:17}
 
 %D This file is loaded at runtime, thereby providing an excellent place for hacks,
 %D patches, extensions and new features. There can be local overloads in cont-loc
diff --git a/tex/context/base/mkiv/context.mkiv b/tex/context/base/mkiv/context.mkiv
index 146d9b365..6cc906cf4 100644
--- a/tex/context/base/mkiv/context.mkiv
+++ b/tex/context/base/mkiv/context.mkiv
@@ -49,7 +49,7 @@
 %D {YYYY.MM.DD HH:MM} format.
 
 \edef\contextformat {\jobname}
-\edef\contextversion{2021.10.24 21:42}
+\edef\contextversion{2021.10.28 10:17}
 
 %D Kind of special:
 
diff --git a/tex/context/base/mkiv/core-con.lua b/tex/context/base/mkiv/core-con.lua
index 289a34b0e..ea11ffcd0 100644
--- a/tex/context/base/mkiv/core-con.lua
+++ b/tex/context/base/mkiv/core-con.lua
@@ -2011,7 +2011,9 @@ function converters.totime(s)
         return s
     elseif type(s) == "string" then
         local t = lpegmatch(p,s)
-        if t.tzh then
+        if not t then
+            logs.report("system","invalid time specification %a",s)
+        elseif t.tzh then
             local localtzh, localtzm = ostimezone(true)
             t.hour = t.hour + localtzh - t.tzs * t.tzh
             t.min  = t.min  + localtzm - t.tzs * t.tzm
diff --git a/tex/context/base/mkiv/mult-low.lua b/tex/context/base/mkiv/mult-low.lua
index ef9a33153..125434d9a 100644
--- a/tex/context/base/mkiv/mult-low.lua
+++ b/tex/context/base/mkiv/mult-low.lua
@@ -91,7 +91,7 @@ return {
         "localboxgroupcode", "splitoffgroupcode", "splitkeepgroupcode", "preamblegroupcode",
         "alignsetgroupcode", "finrowgroupcode", "discretionarygroupcode",
         --
-        "markautomigrationcode",  "insertautomigrationcode", "preautomigrationcode", "postautomigrationcode",
+        "markautomigrationcode", "insertautomigrationcode", "adjustautomigrationcode", "preautomigrationcode", "postautomigrationcode",
         --
         "charnodecode", "hlistnodecode", "vlistnodecode", "rulenodecode", "insertnodecode", "marknodecode",
         "adjustnodecode", "ligaturenodecode", "discretionarynodecode", "whatsitnodecode", "mathnodecode",
diff --git a/tex/context/base/mkiv/status-files.pdf b/tex/context/base/mkiv/status-files.pdf
index 894a4da54..4a0bc353d 100644
--- a/tex/context/base/mkiv/status-files.pdf
+++ b/tex/context/base/mkiv/status-files.pdf
diff --git a/tex/context/base/mkiv/status-lua.pdf b/tex/context/base/mkiv/status-lua.pdf
index fe34b4772..78253afaf 100644
--- a/tex/context/base/mkiv/status-lua.pdf
+++ b/tex/context/base/mkiv/status-lua.pdf
diff --git a/tex/context/base/mkxl/anch-bar.mkxl b/tex/context/base/mkxl/anch-bar.mkxl
index 9fa9d6bf2..23a009e97 100644
--- a/tex/context/base/mkxl/anch-bar.mkxl
+++ b/tex/context/base/mkxl/anch-bar.mkxl
@@ -78,6 +78,7 @@
    \c!bottomoffset=\zeropoint,
    \c!distance=.5\bodyfontsize,
    \c!level=,
+   \c!location=\v!left,
    \c!leftmargindistance=\zeropoint]
 
 \aliased\let\setupsidebars\setupsidebar
@@ -124,6 +125,7 @@
        {e:sidebar:\the\c_anch_sidebars_n}%
        {mpos:sidebar}%
        {self=sidebar:\the\c_anch_sidebars_n,
+        location=\mplocation{\sidebarparameter\c!location},
         linewidth=\sidebarparameter\c!rulethickness,
         linecolor=\sidebarparameter\c!rulecolor,
         alternative=\sidebarparameter\c!alternative,
diff --git a/tex/context/base/mkxl/cont-new.mkxl b/tex/context/base/mkxl/cont-new.mkxl
index b300fcf1b..c09d7a8ae 100644
--- a/tex/context/base/mkxl/cont-new.mkxl
+++ b/tex/context/base/mkxl/cont-new.mkxl
@@ -13,7 +13,7 @@
 
 % \normalend % uncomment this to get the real base runtime
 
-\newcontextversion{2021.10.24 21:42}
+\newcontextversion{2021.10.28 10:17}
 
 %D This file is loaded at runtime, thereby providing an excellent place for hacks,
 %D patches, extensions and new features. There can be local overloads in cont-loc
diff --git a/tex/context/base/mkxl/context.mkxl b/tex/context/base/mkxl/context.mkxl
index 41d4e1ca3..afb958933 100644
--- a/tex/context/base/mkxl/context.mkxl
+++ b/tex/context/base/mkxl/context.mkxl
@@ -29,7 +29,7 @@
 %D {YYYY.MM.DD HH:MM} format.
 
 \immutable\edef\contextformat {\jobname}
-\immutable\edef\contextversion{2021.10.24 21:42}
+\immutable\edef\contextversion{2021.10.28 10:17}
 
 %overloadmode 1 % check frozen / warning
 %overloadmode 2 % check frozen / error
@@ -387,6 +387,7 @@
 
 \loadmkxlfile{typo-tal}
 \loadmkxlfile{typo-par} % par builders (uses fonts)
+\loadmkxlfile{typo-lbx}
 
 \loadmkxlfile{tabl-com}
 %loadmarkfile{tabl-pln}
diff --git a/tex/context/base/mkxl/grph-inc.lmt b/tex/context/base/mkxl/grph-inc.lmt
index 8c4cb62b3..0ba4b093c 100644
--- a/tex/context/base/mkxl/grph-inc.lmt
+++ b/tex/context/base/mkxl/grph-inc.lmt
@@ -1316,7 +1316,7 @@ function figures.identify(data)
         for i=1,#list do
             local identifier = list[i]
             local data = identifier(data)
-            if data and (not data.status and data.status.status > 0) then
+            if data and data.status and (not data.status and data.status.status > 0) then
                 break
             end
         end
diff --git a/tex/context/base/mkxl/node-par.lmt b/tex/context/base/mkxl/node-par.lmt
index 290c2fbd8..fb492b84b 100644
--- a/tex/context/base/mkxl/node-par.lmt
+++ b/tex/context/base/mkxl/node-par.lmt
@@ -95,6 +95,23 @@ do
 
 end
 
+-- These are node handlers but fit it the overall paragraph handling so we
+-- hook it into the callback here.
+
+do
+
+    local localboxactions = nodes.tasks.actions("localboxes")
+
+    function localboxfilter(...)
+        starttiming(builders)
+        localboxactions(...)
+        stoptiming(builders)
+    end
+
+    callbacks.register("local_box_filter",localboxfilter,"process local boxes")
+
+end
+
 -- This means that we now have most callbacks in use, even the ones that I'm not sure
 -- about. It also means that with the above enabled we might have performance now at
 -- its worst. I can optimize this a little but it's not worth the effort (and added
diff --git a/tex/context/base/mkxl/node-tsk.lmt b/tex/context/base/mkxl/node-tsk.lmt
index 61e5bc0d4..c12c9597e 100644
--- a/tex/context/base/mkxl/node-tsk.lmt
+++ b/tex/context/base/mkxl/node-tsk.lmt
@@ -952,3 +952,55 @@ nonut = [[
 --
 --     }
 -- }
+
+-- -- localboxes -- --
+
+tasks.new {
+    name      = "localboxes",
+    processor = nodeprocessor,
+    sequence  = {
+        "before",      -- for users
+        "lists",
+        "after",       -- for users
+    },
+    templates = {
+
+default = [[
+return function(head)
+end
+]],
+
+process = [[
+local tonut  = nodes.tonut
+local tonode = nodes.nuts.tonode
+
+%localize%
+
+-- line,leftbox,rightbox,linenumber,leftskip,rightskip,lefthang,righthang,indent,parfillleftskip,parfillrightskip
+
+return function(line,leftbox,rightbox,...)
+    nutline     = tonut(line)
+    nutleftbox  = leftbox  and tonut(leftbox)
+    nutrightbox = rightbox and tonut(rightbox)
+%actions%
+end
+]],
+
+step = [[
+    tonut((%action%(line,leftbox,rightbox,...)))
+]],
+
+nut  = [[
+    %action%(nutline,nutleftbox,nutrightbox,...)
+]],
+
+nohead = [[
+    %action%(line,leftbox,rightbox,...)
+]],
+
+nonut = [[
+    %action%(nutline,nutleftbox,nutrightbox,...)
+]],
+
+    }
+}
diff --git a/tex/context/base/mkxl/spac-hor.mkxl b/tex/context/base/mkxl/spac-hor.mkxl
index 0b047ccff..06a8f74f4 100644
--- a/tex/context/base/mkxl/spac-hor.mkxl
+++ b/tex/context/base/mkxl/spac-hor.mkxl
@@ -1217,4 +1217,16 @@
 \permanent\protected\def\interwordspacesafter #1{\dofastloopcs{#1}\interwordspaceafter}
 \permanent\protected\def\interwordspaces      #1{\wordboundary\zwnj\dofastloopcs{\numexpr#1+\minusone}\interwordspaceafter}
 
+%D For mp:
+
+\installcorenamespace{mplocation}
+
+\defcsname\??mplocation\v!left \endcsname{1}
+\defcsname\??mplocation\v!right\endcsname{2}
+\defcsname\??mplocation\v!inner\endcsname{3}
+\defcsname\??mplocation\v!outer\endcsname{4}
+
+\permanent\def\mplocation#1{\ifcsname\??mplocation#1\endcsname\lastnamedcs\else0\fi}
+%permanent\def\mplocation#1{\csname\??mplocation\ifcsname\??mplocation#1\endcsname#1\else\v!left\fi\endcsname}
+
 \protect \endinput
diff --git a/tex/context/base/mkxl/syst-ini.mkxl b/tex/context/base/mkxl/syst-ini.mkxl
index a873d15a3..11b7c1262 100644
--- a/tex/context/base/mkxl/syst-ini.mkxl
+++ b/tex/context/base/mkxl/syst-ini.mkxl
@@ -1414,4 +1414,9 @@
 \autoparagraphmode\plusone  % we need at least 1 in order to be able to switch to 2
 %autoparagraphmode\plustwo  % because we define two \par delimited macros
 
+%D The same values apply as \type {\shownodedetails}. When set the box is shown in
+%D the the log file but that is pretty slow when we have much detail.
+
+\tracingfullboxes\zerocount
+
 \protect \endinput
diff --git a/tex/context/base/mkxl/task-ini.lmt b/tex/context/base/mkxl/task-ini.lmt
index 78d7ab657..0018ed690 100644
--- a/tex/context/base/mkxl/task-ini.lmt
+++ b/tex/context/base/mkxl/task-ini.lmt
@@ -151,6 +151,8 @@ appendaction("everypar",     "normalizers", "nodes.handlers.checkparcounter",
 
 appendaction("alignments",   "normalizers", "nodes.handlers.aligncharacter",                    nil, "nut",    "disabled"  )
 
+appendaction("localboxes",   "lists",       "typesetters.localboxes.handler",                   nil, "nut",    "enabled"   )
+
 -- some protection
 
 freezecallbacks("find_.*_file", "find file using resolver")
@@ -189,6 +191,8 @@ freezegroup("everypar",     "normalizers")
 
 freezegroup("alignments",   "normalizers")
 
+freezegroup("localboxes",   "lists")
+
 -- new: disabled here
 
 directives.register("nodes.basepass", function(v)
diff --git a/tex/context/base/mkxl/typo-lbx.lmt b/tex/context/base/mkxl/typo-lbx.lmt
new file mode 100644
index 000000000..00ba1cc7f
--- /dev/null
+++ b/tex/context/base/mkxl/typo-lbx.lmt
@@ -0,0 +1,179 @@
+if not modules then modules = { } end modules ['typo-lbx'] = {
+    version   = 1.001,
+    optimize  = true,
+    comment   = "companion to typo-lbx.mkxl",
+    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+    copyright = "PRAGMA ADE / ConTeXt Development Team",
+    license   = "see context related readme files"
+}
+
+local tostring = tostring
+
+local nuts             = nodes.nuts
+
+local left_box_code    = nodes.listcodes.left
+local right_box_code   = nodes.listcodes.right
+local hlist_code       = nodes.nodecodes.hlist
+
+local getlist          = nuts.getlist
+local getprev          = nuts.getprev
+local getnext          = nuts.getnext
+local getattribute     = nuts.getattribute
+local gettail          = nuts.tail
+local getwidth         = nuts.getwidth
+local setlist          = nuts.setlist
+local setoffsets       = nuts.setoffsets
+local flushlist        = nuts.flushlist
+local takebox          = nuts.takebox
+local setbox           = nuts.setbox
+local copynode         = nuts.copynode
+local rangedimensions  = nuts.rangedimensions
+local traverse_list    = nuts.traversers.list
+
+local expandmacro      = token.expandmacro
+
+local dimension_value  = tokens.values.dimension
+local integer_value    = tokens.values.integer
+
+local implement        = interfaces.implement
+
+typesetters            = typesetters or { }
+local typesetters      = typesetters
+
+typesetters.localboxes = typesetters.localboxes or { }
+local localboxes       = typesetters.localboxes
+
+local a_localboxes     = attributes.private("localboxes")
+
+local starttiming      = statistics.starttiming
+local stoptiming       = statistics.stoptiming
+
+do
+
+    local lb_attribute        = 0
+    local lb_linenumber       = 0
+    local lb_width            = 0
+    local lb_offset           = 0
+    local lb_leftskip         = 0
+    local lb_rightskip        = 0
+    local lb_lefthang         = 0
+    local lb_righthang        = 0
+    local lb_indent           = 0
+    local lb_parfillleftskip  = 0
+    local lb_parfillrightskip = 0
+    local lb_overshoot        = 0
+
+    implement { name = "localboxattribute",        public = true, usage = "value", actions = function() return integer_value,   lb_attribute        end }
+    implement { name = "localboxlinenumber",       public = true, usage = "value", actions = function() return integer_value,   lb_linenumber       end }
+    implement { name = "localboxwidth",            public = true, usage = "value", actions = function() return dimension_value, lb_width            end }
+    implement { name = "localboxoffset",           public = true, usage = "value", actions = function() return dimension_value, lb_offset           end }
+    implement { name = "localboxleftskip",         public = true, usage = "value", actions = function() return dimension_value, lb_leftskip         end }
+    implement { name = "localboxrightskip",        public = true, usage = "value", actions = function() return dimension_value, lb_rightskip        end }
+    implement { name = "localboxlefthang",         public = true, usage = "value", actions = function() return dimension_value, lb_lefthang         end }
+    implement { name = "localboxrighthang",        public = true, usage = "value", actions = function() return dimension_value, lb_righthang        end }
+    implement { name = "localboxindent",           public = true, usage = "value", actions = function() return dimension_value, lb_indent           end }
+    implement { name = "localboxparfillleftskip",  public = true, usage = "value", actions = function() return dimension_value, lb_parfillleftskip  end }
+    implement { name = "localboxparfillrightskip", public = true, usage = "value", actions = function() return dimension_value, lb_parfillrightskip end }
+    implement { name = "localboxovershoot",        public = true, usage = "value", actions = function() return dimension_value, lb_overshoot        end }
+
+    local function action(current,where)
+        -- We can have nested leftboxes!
+        local l = getlist(current)
+        setlist(current)
+        local h = copynode(current)
+        setlist(h,l)
+        setbox("localboxcontentbox",h)
+        expandmacro("localboxcommand") -- no longer pass arguments
+        local b = takebox("localboxcontentbox")
+        setlist(current,b)
+        if where == "left" then
+            local w = getwidth(b)
+            setoffsets(b,lb_width - lb_offset - w)
+        else
+            setoffsets(b,lb_offset - lb_width)
+        end
+    end
+
+    local function processleftbox(box,width)
+        local list = getlist(box)
+        if not width then
+            width = 0
+        end
+        for current, id, subtype in traverse_list, list do
+            if id == hlist_code then
+                local a = getattribute(current,a_localboxes)
+                if a then
+                    lb_attribute = a
+                    lb_width     = width + rangedimensions(box,list,getprev(current))
+                    action(current,"left")
+                end
+                if subtype == left_box_code then
+                    processleftbox(current,width + rangedimensions(box,list,getprev(current)))
+                end
+            end
+        end
+    end
+
+    local function processrightbox(box,width)
+        local list = getlist(box)
+        local tail = gettail(list)
+        if not width then
+            width = 0
+        end
+        for current, id, subtype in traverse_list, list do
+            if id == hlist_code then
+                local a = getattribute(current,a_localboxes)
+                if a then
+                    lb_attribute = a
+                    lb_width     = width + rangedimensions(box,list,getnext(current),tail)
+                    action(current,"right")
+                end
+                if subtype == right_box_code then
+                    processrightbox(current,width + rangedimensions(box,getnext(current),tail))
+                end
+            end
+        end
+    end
+
+    local function processlocalboxes(line, leftbox, rightbox, linenumber, leftskip, rightskip, lefthang, righthang, indent, parfillleftskip, parfillrightskip, overshoot)
+        --
+        lb_attribute        = 0
+        lb_linenumber       = linenumber
+        lb_width            = 0
+     -- lb_offset           = 0
+        lb_leftskip         = leftskip
+        lb_rightskip        = rightskip
+        lb_lefthang         = lefthang
+        lb_righthang        = righthang
+        lb_indent           = indent
+        lb_parfillleftskip  = parfillleftskip
+        lb_parfillrightskip = parfillrightskip
+        lb_overshoot        = overshoot
+        --
+        -- for now we always anchor
+        --
+        if leftbox then
+            lb_offset = leftskip + lefthang + indent + parfillleftskip + getwidth(leftbox)
+            processleftbox(leftbox)
+        end
+        if rightbox then
+            lb_offset = rightskip + righthang + parfillrightskip + getwidth(rightbox) - overshoot
+            processrightbox(rightbox)
+        end
+    end
+
+    typesetters.localboxes.handler = processlocalboxes
+
+end
+
+local localboxactions = nodes.tasks.actions("localboxes")
+
+function builders.local_box_filter(...)
+    starttiming(builders)
+    localboxactions(...)
+    stoptiming(builders)
+end
+
+-- we register the function elsewhere
+
+callbacks.register("local_box_filter", builders.local_box_filter, "process local boxes")
diff --git a/tex/context/base/mkxl/typo-lbx.mkxl b/tex/context/base/mkxl/typo-lbx.mkxl
new file mode 100644
index 000000000..f8d252a27
--- /dev/null
+++ b/tex/context/base/mkxl/typo-lbx.mkxl
@@ -0,0 +1,229 @@
+%D \module
+%D   [       file=typo-dig,
+%D        version=2010.01.18,
+%D          title=\CONTEXT\ Typesetting Macros,
+%D       subtitle=Digits,
+%D         author=Hans Hagen,
+%D           date=\currentdate,
+%D      copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
+%C details.
+
+\writestatus{loading}{ConTeXt Typesetting Macros / Local Boxes}
+
+% musical timestamp: New Scary Goldings ft. John Scofield MonoNeon & Louis Cole (late
+% October 2021)
+
+% maybe: \iflocalleftbox
+
+\registerctxluafile{typo-lbx}{autosuffix}
+
+%D The advantage is that it's deal with in the par builder which has some advantages
+%D but when used in complex situation there can be side effects. Therefore is should
+%D be considered a somewhat low level mechanism on top of which one can write more
+%D mechanisms that provide more rendering control. Also, keep in mind that combining
+%D many instances at the same time add some complizity. Therefore, for the moment it's
+%D a playground.
+
+
+\unprotect
+
+\def\v!lefttext {lefttext}
+\def\v!righttext{righttext}
+
+\appendtoks
+    \localleftbox {}% \nolocalboxes : we don't have a nice command category for it
+    \localrightbox{}%
+\to\everyforgetall
+
+\definesystemattribute[localboxes][public]
+
+%D We used to pass arguments but there might be many so ...
+
+\newbox\localboxcontentbox
+
+\installcorenamespace{localboxes}
+\installcorenamespace{localboxesattribute}
+\installcorenamespace{localboxesnamespace}
+\installcorenamespace{localboxeslocations}
+
+\installcommandhandler \??localboxes {localboxes} \??localboxes
+
+\setuplocalboxes
+  [\c!location=\v!left]
+
+\newcount\c_typo_localboxes
+
+\appendtoks
+    \global\advance\c_typo_localboxes\plusone
+    \global\expandafter\integerdef\csname\??localboxesattribute\currentlocalboxes\endcsname\c_typo_localboxes
+    \gletcsname\??localboxesnamespace\number\c_typo_localboxes\endcsname\currentlocalboxes
+\to \everydefinelocalboxes
+
+%D The optional argument forces seting the \quote {whole} paragraph properties (which is needed
+%D when the assignment happens after e.g.\ \type {\everypar} but is also meant for the first
+%D line.
+
+\def\typo_paragraphs_l#1{\localleftbox \ifcstok{#1}\v!global par\fi}
+\def\typo_paragraphs_r#1{\localrightbox\ifcstok{#1}\v!global par\fi}
+
+\permanent\tolerant\protected\def\leftparbox        [#1]{\typo_paragraphs_l{#1}\bgroup\enforced\let\leftparbox \relax\let\next}
+\permanent\tolerant\protected\def\rightparbox       [#1]{\typo_paragraphs_r{#1}\bgroup\enforced\let\rightparbox\relax\let\next}
+
+\permanent\tolerant\protected\def\appendleftparbox  [#1]{\dowithnextbox{\leftparbox [#1]{\the\localleftbox \unhbox\nextbox}}\hbox}
+\permanent\tolerant\protected\def\appendrightparbox [#1]{\dowithnextbox{\rightparbox[#1]{\the\localrightbox\unhbox\nextbox}}\hbox}
+
+\permanent\tolerant\protected\def\prependleftparbox [#1]{\dowithnextbox{\leftparbox [#1]{\unhbox\nextbox\the\localleftbox }}\hbox}
+\permanent\tolerant\protected\def\prependrightparbox[#1]{\dowithnextbox{\rightparbox[#1]{\unhbox\nextbox\the\localrightbox}}\hbox}
+
+\permanent\tolerant\protected\def\resetleftparbox   [#1]{\typo_paragraphs_l{#1}{}}
+\permanent\tolerant\protected\def\resetrightparbox  [#1]{\typo_paragraphs_r{#1}{}}
+
+% called back:
+
+\permanent\protected\def\localboxcommand
+  {\ifcsname\??localboxesnamespace\number\localboxattribute\endcsname
+    %\edef\currentlocalboxes{\lastnamedcs}%
+     \expandafter\let\expandafter\currentlocalboxes\lastnamedcs
+     \setbox\localboxcontentbox\hbox
+       {\uselocalboxesstyleandcolor\c!style\c!color
+        \localboxesparameter\c!command}%
+   \fi}
+
+%D We don't group because we set the local boxes. Also, watch out: by injecting the
+%D existing local box we create nested ones. This is handled in the callback but if
+%D really needed one can do something like (do we need a primitive?):
+
+% \localrightbox{%
+%   \the\localrightbox
+%   \setbox\scratchbox\lastbox
+%   \unhbox\scratchbox
+%   additional}%
+
+\def\typo_localboxes_zero#1#2%
+  {\ifcsname\??localboxesattribute#1\endcsname
+     \hpack attr \localboxesattribute \lastnamedcs to \zeropoint \bgroup
+        \edef\currentlocalboxes{#1}%
+        #2%
+     \egroup
+   \fi}
+
+\def\typo_localboxes_asis#1#2%
+  {\hpack \bgroup  % todo: use width if dimension, use distance if given
+     \edef\currentlocalboxes{#1}%
+     \localboxesparameter\c!command{#2}%
+   \egroup}
+
+\defcsname\??localboxeslocations\v!left\endcsname#1#2%
+  {\leftparbox \bgroup
+     \typo_localboxes_zero{#1}{#2}%
+     \the\localleftbox
+   \egroup}
+
+\defcsname\??localboxeslocations\v!right\endcsname#1#2%
+  {\rightparbox \bgroup
+     \the\localrightbox
+     \typo_localboxes_zero{#1}{#2}%
+   \egroup}
+
+\defcsname\??localboxeslocations\v!lefttext\endcsname#1#2%
+  {\leftparbox \bgroup
+     \typo_localboxes_asis{#1}{#2}%
+     \the\localleftbox
+   \egroup}
+
+\defcsname\??localboxeslocations\v!righttext\endcsname#1#2%
+  {\rightparbox \bgroup
+     \the\localrightbox
+     \typo_localboxes_asis{#1}{#2}%
+   \egroup}
+
+\permanent\tolerant\protected\def\localbox[#1]%
+  {\dowithnextboxcontent
+     {\edef\currentlocalboxes{#1}%
+      \uselocalboxesstyleandcolor\c!style\c!color}
+     {\ifcsname\??localboxeslocations\namedlocalboxesparameter{#1}\c!location\endcsname
+        \expandafter\lastnamedcs
+      \else
+        \csname\??localboxeslocations\v!left\expandafter\endcsname
+      \fi{#1}{\unhbox\nextbox}}%
+     \hbox}
+
+\permanent\tolerant\protected\def\startlocalbox[#1]%
+  {\dowithnextbox
+     {\ifcsname\??localboxeslocations\namedlocalboxesparameter{#1}\c!location\endcsname
+         \expandafter\lastnamedcs
+       \else
+         \csname\??localboxeslocations\v!left\expandafter\endcsname
+       \fi{#1}{\unhbox\nextbox}}%
+     \hbox\bgroup
+     \edef\currentlocalboxes{#1}%
+     \uselocalboxesstyleandcolor\c!style\c!color
+     \enforced\def\stoplocalbox{\removeunwantedspaces\egroup}%
+     \ignorespaces}
+
+\aliased\let\stoplocalbox\donothing
+
+%D Here is an example of usage:
+
+%D \starttyping
+%D \definelocalboxes
+%D   [linenumber]
+%D   [command=\LeftNumber,location=left,width=3em,style=\bs,color=darkred]
+%D
+%D \definelocalboxes
+%D   [linenumbertwo] [linenumber]
+%D   [command=\RightNumber,location=right,width=6em,style=\bf,color=darkgreen]
+%D
+%D \definelocalboxes
+%D   [linetext]
+%D   [command=\LeftText,location=lefttext,style=\bs,color=darkblue]
+%D
+%D \definelocalboxes
+%D   [linetexttwo] [linetext]
+%D   [command=\RightText,location=righttext,style=\bf,color=darkgray]
+%D
+%D % \def\LineNumberL{\the\localboxlinenumber}
+%D % \def\LineNumberR{\the\localboxlinenumber}
+%D
+%D % \newcount\MyLineNumberL
+%D % \newcount\MyLineNumberR
+%D % \def\LineNumberL{\global\advance\MyLineNumberL\plusone\the\MyLineNumberL}
+%D % \def\LineNumberR{\global\advance\MyLineNumberR\plusone\the\MyLineNumberR}
+%D
+%D \definecounter[MyLineNumberL]
+%D \definecounter[MyLineNumberR]
+%D
+%D \setupcounter[MyLineNumberL][numberconversion=characters]
+%D \setupcounter[MyLineNumberR][numberconversion=romannumerals]
+%D
+%D \def\LineNumberL{\incrementcounter[MyLineNumberL]\convertedcounter[MyLineNumberL]}
+%D \def\LineNumberR{\incrementcounter[MyLineNumberR]\convertedcounter[MyLineNumberR]}
+%D
+%D \protected\def\LeftNumber {\hbox to \localboxesparameter{width}{\strut(\LineNumberL\hss)}}
+%D \protected\def\RightNumber{\hbox to \localboxesparameter{width}{\strut(\hss\LineNumberR)}}
+%D
+%D % \protected\def\LeftNumber {\hbox to \localboxesparameter{width}{\strut\box\localboxcontentbox\hss)}}
+%D % \protected\def\RightNumber{\hbox to \localboxesparameter{width}{\strut(\hss\box\localboxcontentbox)}}
+%D
+%D \protected\def\LeftText #1{#1\quad}
+%D \protected\def\RightText#1{\quad#1}
+%D
+%D \start
+%D     \localbox[linenumber]{}%
+%D     \localbox[linenumbertwo]{}%
+%D     \localbox[linetext]{L}%
+%D     \startlocalbox[linetexttwo]
+%D         R
+%D     \stoplocalbox
+%D     \dorecurse{100}{
+%D         \samplefile{tufte}
+%D         \par
+%D     }
+%D \stop
+%D \stoptyping
+
+\protect \endinput
+
diff --git a/tex/context/interface/mkii/keys-ro.xml b/tex/context/interface/mkii/keys-ro.xml
index 158a8b8ac..447cfd580 100644
--- a/tex/context/interface/mkii/keys-ro.xml
+++ b/tex/context/interface/mkii/keys-ro.xml
@@ -191,6 +191,7 @@
 		<cd:variable name='enumeration' value='enumerare'/>
 		<cd:variable name='environment' value='mediu'/>
 		<cd:variable name='even' value='par'/>
+		<cd:variable name='explicit' value='explicit'/>
 		<cd:variable name='export' value='export'/>
 		<cd:variable name='external' value='extern'/>
 		<cd:variable name='extremestretch' value='extremestretch'/>