2018-03-23 13:20:00

14 files changed, 273 insertions, 136 deletions

diff --git a/tex/context/base/mkii/cont-new.mkii b/tex/context/base/mkii/cont-new.mkii
index 6603bb01f..63e666b79 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{2018.03.22 19:41}
+\newcontextversion{2018.03.23 13:13}
 
 %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 acfda88dc..efce78a75 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{2018.03.22 19:41}
+\edef\contextversion{2018.03.23 13:13}
 
 %D For those who want to use this:
 
diff --git a/tex/context/base/mkiv/cont-new.mkiv b/tex/context/base/mkiv/cont-new.mkiv
index 10ae9d1df..0c05ea230 100644
--- a/tex/context/base/mkiv/cont-new.mkiv
+++ b/tex/context/base/mkiv/cont-new.mkiv
@@ -11,7 +11,7 @@
 %C therefore copyrighted by \PRAGMA. See mreadme.pdf for
 %C details.
 
-\newcontextversion{2018.03.22 19:41}
+\newcontextversion{2018.03.23 13:13}
 
 %D This file is loaded at runtime, thereby providing an excellent place for
 %D hacks, patches, extensions and new features.
diff --git a/tex/context/base/mkiv/context.mkiv b/tex/context/base/mkiv/context.mkiv
index cef988ce7..900a7488b 100644
--- a/tex/context/base/mkiv/context.mkiv
+++ b/tex/context/base/mkiv/context.mkiv
@@ -42,7 +42,7 @@
 %D has to match \type {YYYY.MM.DD HH:MM} format.
 
 \edef\contextformat {\jobname}
-\edef\contextversion{2018.03.22 19:41}
+\edef\contextversion{2018.03.23 13:13}
 \edef\contextkind   {beta}
 
 %D For those who want to use this:
diff --git a/tex/context/base/mkiv/lxml-tex.lua b/tex/context/base/mkiv/lxml-tex.lua
index f1abab9e7..43b8e16b1 100644
--- a/tex/context/base/mkiv/lxml-tex.lua
+++ b/tex/context/base/mkiv/lxml-tex.lua
@@ -64,10 +64,11 @@ local xmlrename          = xml.rename
 
 local variables          = interfaces and interfaces.variables or { }
 
-local settings_to_hash   = utilities.parsers.settings_to_hash
-local settings_to_set    = utilities.parsers.settings_to_set
-local options_to_hash    = utilities.parsers.options_to_hash
-local options_to_array   = utilities.parsers.options_to_array
+local parsers            = utilities.parsers
+local settings_to_hash   = parsers.settings_to_hash
+local settings_to_set    = parsers.settings_to_set
+local options_to_hash    = parsers.options_to_hash
+local options_to_array   = parsers.options_to_array
 
 local insertbeforevalue  = utilities.tables.insertbeforevalue
 local insertaftervalue   = utilities.tables.insertaftervalue
diff --git a/tex/context/base/mkiv/meta-grd.mkiv b/tex/context/base/mkiv/meta-grd.mkiv
index 8b1a934d6..15a4471e7 100644
--- a/tex/context/base/mkiv/meta-grd.mkiv
+++ b/tex/context/base/mkiv/meta-grd.mkiv
@@ -13,6 +13,8 @@
 
 \writestatus{loading}{MetaPost Graphics / Grids}
 
+\unprotect
+
 %D This used to be a \TEX\ method, and a rather old one too. We keep it around but
 %D in a more modern way.
 %D
@@ -31,85 +33,177 @@
 %D   {An example of a grid.}
 %D   {\getbuffer}
 
-\startuseMPgraphic{grid}{nx,ny,dx,dy,factor,scale,xstep,ystep,xoffset,yoffset,align}
+% \startuseMPgraphic{grid}{nx,ny,dx,dy,factor,scale,xstep,ystep,xoffset,yoffset,align,s:textcolor,s:rulecolor,rulethickness}
+%     begingroup ;
+%         save dx, dy, wd, ht, ox, oy, ax, ay ;
+%
+%         (dx,dy) = (\MPvar{dx},\MPvar{dy})*\MPvar{factor}*\MPvar{scale} ;
+%         (wd,ht) = (\MPvar{nx}*dx,\MPvar{ny}*dy) ;
+%         (ox,oy) = (\MPvar{xoffset},\MPvar{yoffset}) ;
+%         (ax,ay) = if \MPvar{align} = 1 : (dx,dy)/2 else : origin fi ;
+%
+%         draw image (
+%             for i=0 step dx until wd : draw (i,0) -- (i,ht) ; endfor ;
+%             for i=0 step dy until ht : draw (0,i) -- (wd,i) ; endfor ;
+%         )
+%             withpen pencircle scaled \MPvar{rulethickness}
+%             withcolor "\MPvar{rulecolor}" ;
+%         draw image (
+%             if \MPvar{xstep} > 0 :
+%                 for i=1 step \MPvar{xstep} until \MPvar{nx} :
+%                     draw thetextext.bot(decimal i,(i*dx-ax,-ox));
+%                 endfor ;
+%             fi ;
+%             if \MPvar{ystep} > 0 :
+%                 for i=1 step \MPvar{ystep} until \MPvar{ny} :
+%                     draw thetextext.lft(decimal i,(-oy,i*dy-ay)) ;
+%                 endfor ;
+%             fi ;
+%         )
+%             withcolor "\MPvar{color}" ;
+%     endgroup ;
+% \stopuseMPgraphic
+%
+% less tokens (not used often):
+%
+% \startuseMPgraphic{grid}{\c!nx,\c!ny,\c!dx,\c!dy,\c!factor,\c!scale,\c!xstep,\c!ystep,\c!xoffset,\c!yoffset,\c!align,s:\c!textcolor,s:\c!rulecolor,\c!rulethickness}
+%     begingroup ;
+%         save dx, dy, wd, ht, ox, oy, ax, ay ;
+%
+%         (dx,dy) = (\MPvar\c!dx,\MPvar\c!dy)*\MPvar\c!factor*\MPvar\c!scale ;
+%         (wd,ht) = (\MPvar\c!nx*dx,\MPvar\c!ny*dy) ;
+%         (ox,oy) = (\MPvar\c!xoffset,\MPvar\c!yoffset) ;
+%         (ax,ay) = if \MPvar\c!align = 1 : (\c!dx,\c!dy)/2 else : origin fi ;
+%
+%         draw image (
+%             for i=0 step dx until wd : draw (i,0) -- (i,ht) ; endfor ;
+%             for i=0 step dy until ht : draw (0,i) -- (wd,i) ; endfor ;
+%         )
+%             withpen pencircle scaled \MPvar\c!rulethickness\space
+%             withcolor "\MPvar\c!rulecolor" ;
+%         draw image (
+%             if \MPvar\c!xstep > 0 :
+%                 for i=1 step \MPvar\c!xstep until \MPvar\c!nx :
+%                     draw thetextext.bot(decimal i,(i*dx-ax,-ox));
+%                 endfor ;
+%             fi ;
+%             if \MPvar\c!ystep > 0 :
+%                 for i=1 step \MPvar\c!ystep until \MPvar\c!ny :
+%                     draw thetextext.lft(decimal i,(-oy,i*dy-ay)) ;
+%                 endfor ;
+%             fi ;
+%         )
+%             withcolor "\MPvar\c!color" ;
+%     endgroup ;
+% \stopuseMPgraphic
+%
+% \def\typo_grid_base[#1]%
+%   {\dontleavehmode
+%    \hbox\bgroup
+%    \getdummyparameters
+%      [\c!nx=10,\c!ny=10,\c!dx=.5,\c!dy=.5,\c!xstep=0,\c!ystep=0,%
+%       \c!unit=\s!cm,\c!scale=1,\c!factor=1,%
+%       \c!offset=.25ex,%
+%       \c!xoffset=\directdummyparameter\c!offset,%
+%       \c!yoffset=\directdummyparameter\c!offset,%
+%       \c!align=,%
+%       \c!color=\currentcolorname,%
+%       \c!rulecolor=\currentcolorname,%
+%       \c!rulethickness=\linewidth,%
+%       #1]%
+%    \usedummystyleandcolor\c!style\c!color
+%    \edef\p_align{\directdummyparameter\c!align}%
+%    \edef\p_unit {\directdummyparameter\c!unit}%
+%    \useMPgraphic
+%      {grid}%
+%      {nx=\directdummyparameter\c!nx,%
+%       ny=\directdummyparameter\c!ny,%
+%       dx=\directdummyparameter\c!dx\p_unit,%
+%       dy=\directdummyparameter\c!dy\p_unit,%
+%       factor=\directdummyparameter\c!factor,%
+%       scale=\directdummyparameter\c!scale,%
+%       xstep=\directdummyparameter\c!xstep,%
+%       ystep=\directdummyparameter\c!ystep,%
+%       xoffset=\directdummyparameter\c!xoffset,%
+%       yoffset=\directdummyparameter\c!yoffset,%
+%       color=\directdummyparameter\c!color,%
+%       rulecolor=\directdummyparameter\c!rulecolor,%
+%       rulethickness=\directdummyparameter\c!rulethickness,%
+%       align=\ifx\p_align\v!middle\!!plusone\else\!!zerocount\fi}%
+%    \egroup}
+%
+% even less tokens wasted (no need to clog the core with hardly
+% used code):
+
+\startuseMPgraphic{meta:grd:basegrid}
     begingroup ;
 
-        save nx, ny, dx, dy, wd, ht, xstep, ystep, xoffset, yoffset, align, xalign, yalign ;
+        save sc, dx, dy, wd, ht, ox, oy, ax, ay ;
 
-        numeric nx      ; nx      := \MPvar{nx} ;
-        numeric ny      ; ny      := \MPvar{ny} ;
-        numeric dx      ; dx      := \MPvar{factor} * \MPvar{scale} * \MPvar{dx} ;
-        numeric dy      ; dy      := \MPvar{factor} * \MPvar{scale} * \MPvar{dy} ;
-        numeric wd      ; wd      := nx * dx ;
-        numeric ht      ; ht      := ny * dy ;
-        numeric xstep   ; xstep   := \MPvar{xstep} ;
-        numeric ystep   ; ystep   := \MPvar{ystep} ;
-        numeric xoffset ; xoffset := \MPvar{xoffset} ;
-        numeric yoffset ; yoffset := \MPvar{yoffset} ;
-        numeric align   ; align   := \MPvar{align} ;
-        numeric xalign  ; xalign  := 0 ;
-        numeric yalign  ; yalign  := 0 ;
+        sc = \directdummyparameter\c!factor*\directdummyparameter\c!scale ;
+        dx = \MPdpar\directdummyparameter\c!dx*sc ;
+        dy = \MPdpar\directdummyparameter\c!dy*sc ;
+        wd = \directdummyparameter\c!nx*dx ;
+        ht = \directdummyparameter\c!ny*dy ;
+        ox = \MPdpar\directdummyparameter\c!xoffset\relax ;
+        oy = \MPdpar\directdummyparameter\c!yoffset\relax ;
 
-        if align = 1 :
-            xalign := dx/2 ;
-            yalign := dy/2 ;
+        if "\directdummyparameter\c!align" = "\v!middle" :
+            ax = \MPdpar\directdummyparameter\c!dx/2
+            ay = \MPdpar\directdummyparameter\c!dy/2
+        else :
+            ax = 0 ;
+            ay = 0 ;
         fi ;
 
-        for i=0 step dx until wd :
-            draw (i,0) -- (i,ht) ;
-        endfor ;
-        for i=0 step dy until ht :
-            draw (0,i) -- (wd,i) ;
-        endfor ;
+        draw image (
+            for i=0 step dx until wd : draw (i,0) -- (i,ht) ; endfor ;
+            for i=0 step dy until ht : draw (0,i) -- (wd,i) ; endfor ;
+        )
+            withpen pencircle scaled \MPdpar\directdummyparameter\c!rulethickness\space
+            withcolor "\directdummyparameter\c!rulecolor" ;
 
-        if xstep > 0 :
-            for i=1 step xstep until nx :
-                draw thetextext.bot(decimal i,(i*dx-xalign,-xoffset)) ;
-            endfor ;
-        fi ;
-        if ystep > 0 :
-            for i=1 step ystep until ny :
-                draw thetextext.lft(decimal i,(-yoffset,i*dy-yalign)) ;
-            endfor ;
-        fi ;
+        draw image (
+            if \directdummyparameter\c!xstep > 0 :
+                for i=1 step \directdummyparameter\c!xstep until \directdummyparameter\c!nx :
+                    draw thetextext.bot(decimal i,(i*dx-ax,oy));
+                endfor ;
+            fi ;
+            if \directdummyparameter\c!ystep > 0 :
+                for i=1 step \directdummyparameter\c!ystep until \directdummyparameter\c!ny :
+                    draw thetextext.lft(decimal i,(ox,i*dy-ay)) ;
+                endfor ;
+            fi ;
+        )
+            withcolor "\directdummyparameter\c!color" ;
 
     endgroup ;
 \stopuseMPgraphic
 
-\unprotect
-
-\unexpanded\def\basegrid
-  {\dosingleempty\typo_grid_base}
-
 \def\typo_grid_base[#1]%
-  {\hbox\bgroup
+  {\dontleavehmode
+   \hbox\bgroup
    \getdummyparameters
-     [\c!nx=10,\c!ny=10,\c!dx=.5,\c!dy=.5,\c!xstep=0,\c!ystep=0,%
+     [\c!nx=10,\c!ny=10,%
+      \c!dx=.5,\c!dy=.5,%
+      \c!xstep=0,\c!ystep=0,%
       \c!unit=\s!cm,\c!scale=1,\c!factor=1,%
-      \c!offset=.25ex,\c!xoffset=\directdummyparameter\c!offset,\c!yoffset=\directdummyparameter\c!offset,%
-      \c!align=,
+      \c!offset=.25\exheight,%
+      \c!xoffset=\directdummyparameter\c!offset,%
+      \c!yoffset=\directdummyparameter\c!offset,%
+      \c!align=,%
+      \c!color=\currentcolorname,%
+      \c!rulecolor=\currentcolorname,%
+      \c!rulethickness=\linewidth,%
       #1]%
    \usedummystyleandcolor\c!style\c!color
-   \edef\p_align{\directdummyparameter\c!align}%
-   \ifx\p_align\v!middle
-      \let\p_align\!!plusone
-   \else
-      \let\p_align\!!zerocount
-   \fi
-   \useMPgraphic
-    {grid}%
-    {nx=\directdummyparameter\c!nx,%
-     ny=\directdummyparameter\c!ny,%
-     dx=\directdummyparameter\c!dx\directdummyparameter\c!unit,%
-     dy=\directdummyparameter\c!dy\directdummyparameter\c!unit,%
-     factor=\directdummyparameter\c!factor,%
-     scale=\directdummyparameter\c!scale,%
-     xstep=\directdummyparameter\c!xstep,%
-     ystep=\directdummyparameter\c!ystep,%
-     xoffset=\directdummyparameter\c!xoffset,%
-     yoffset=\directdummyparameter\c!yoffset,%
-     align=\p_align}%
-  \egroup}
+   \setexpandeddummyparameter\c!dx{\directdummyparameter\c!dx\directdummyparameter\c!unit}%
+   \setexpandeddummyparameter\c!dy{\directdummyparameter\c!dy\directdummyparameter\c!unit}%
+   \useMPgraphic{meta:grd:basegrid}%
+   \egroup}
+
+\unexpanded\def\basegrid
+  {\dosingleempty\typo_grid_base}
 
 \let\grid\basegrid
 
diff --git a/tex/context/base/mkiv/meta-imp-mat.mkiv b/tex/context/base/mkiv/meta-imp-mat.mkiv
index 11a9ded34..19a5ba385 100644
--- a/tex/context/base/mkiv/meta-imp-mat.mkiv
+++ b/tex/context/base/mkiv/meta-imp-mat.mkiv
@@ -11,78 +11,74 @@
 %C therefore copyrighted by \PRAGMA. See mreadme.pdf for
 %C details.
 
-%D This is just an example library not meant for production.
-
 % A few accents:
-
+%
 % / for cambria
 
 \startMPextensions
 
-    vardef math_stacker_overbracket_shape =
+    vardef math_stacker_bracket_shape(expr delta, rotate) =
         image (
             draw
                 (0,OverlayOffset) --
-                (0,OverlayHeight-OverlayOffset) --
-                (OverlayWidth,OverlayHeight-OverlayOffset) --
+                (0,delta-OverlayOffset) --
+                (OverlayWidth,delta-OverlayOffset) --
                 (OverlayWidth,OverlayOffset)
             withcolor
                 OverlayLineColor ;
             setbounds currentpicture to boundingbox currentpicture bottomenlarged OverlayOffset ;
+            if rotate :
+                currentpicture := currentpicture rotated 180 ;
+            fi ;
         )
     enddef ;
-    vardef math_stacker_underbracket_shape =
-        math_stacker_overbracket_shape rotated 180
-    enddef ;
-    vardef math_stacker_overparent_shape =
+    vardef math_stacker_parent_shape(expr delta, rotate) =
         image (
             draw
                 (0,OverlayOffset) ...
-                (OverlayWidth/2,OverlayHeight-OverlayOffset) ...
+                (OverlayWidth/2,delta-OverlayOffset) ...
                 (OverlayWidth,OverlayOffset)
             withcolor
                 OverlayLineColor ;
             setbounds currentpicture to boundingbox currentpicture bottomenlarged OverlayOffset ;
+            if rotate :
+                currentpicture := currentpicture rotated 180 ;
+            fi ;
         )
     enddef ;
-    vardef math_stacker_underparent_shape =
-        math_stacker_overparent_shape rotated 180
-    enddef ;
-    vardef math_stacker_overbrace_shape =
+    vardef math_stacker_brace_shape(expr delta, rotate) =
         image (
             draw
                 (0,OverlayOffset) ...
-                (OverlayWidth/4-OverlayOffset,OverlayHeight-OverlayOffset) ...
-                (OverlayWidth/2-OverlayOffset,OverlayHeight-OverlayOffset) ...
-                (OverlayWidth/2,OverlayHeight) &
-                (OverlayWidth/2,OverlayHeight) ...
-                (OverlayWidth/2+OverlayOffset,OverlayHeight-OverlayOffset) ...
-                (3OverlayWidth/4+OverlayOffset,OverlayHeight-OverlayOffset) ...
+                (OverlayWidth/4-OverlayOffset,delta-OverlayOffset) ...
+                (OverlayWidth/2-OverlayOffset,delta-OverlayOffset) ...
+                (OverlayWidth/2,delta) &
+                (OverlayWidth/2,delta) ...
+                (OverlayWidth/2+OverlayOffset,delta-OverlayOffset) ...
+                (3OverlayWidth/4+OverlayOffset,delta-OverlayOffset) ...
                 (OverlayWidth,OverlayOffset)
             withcolor
                 OverlayLineColor ;
             setbounds currentpicture to boundingbox currentpicture bottomenlarged OverlayOffset ;
+            if rotate :
+                currentpicture := currentpicture rotated 180 ;
+            fi ;
         )
     enddef ;
-    vardef math_stacker_underbrace_shape =
-        math_stacker_overbrace_shape rotated 180
-    enddef ;
-    vardef math_stacker_overbar_shape =
+    vardef math_stacker_bar_shape(expr rotate) =
         image (
             draw
                 (0,OverlayOffset) -- (OverlayWidth,OverlayOffset)
             withcolor
                 OverlayLineColor ;
             setbounds currentpicture to boundingbox currentpicture bottomenlarged OverlayOffset ;
+            if rotate :
+                currentpicture := currentpicture rotated 180 ;
+            fi ;
         )
     enddef ;
-    vardef math_stacker_underbar_shape =
-        math_stacker_overbar_shape rotated 180
-    enddef ;
-
     % arrows
-
-    vardef math_stacker_arrow_shape(expr axis, ex, em) =
+    vardef math_stacker_arrow_shape(expr axis, ex, em, rotate) =
         image (
             interim ahlength := ex/2;
             drawarrow
@@ -90,9 +86,12 @@
             withcolor
                 OverlayLineColor ;
             setbounds currentpicture to unitsquare xysized(OverlayWidth,ex) ;
+            if rotate :
+                currentpicture := currentpicture rotated 180 ;
+            fi ;
         )
     enddef ;
-    vardef math_stacker_leftrightarrow_shape(expr axis, ex, em) =
+    vardef math_stacker_leftrightarrow_shape(expr axis, ex, em, rotate) =
         image (
             interim ahlength := ex/2;
             drawdblarrow
@@ -100,9 +99,12 @@
             withcolor
                 OverlayLineColor ;
             setbounds currentpicture to unitsquare xysized(OverlayWidth,ex) ;
+            if rotate :
+                currentpicture := currentpicture rotated 180 ;
+            fi ;
         )
     enddef ;
-    vardef math_stacker_rightoverleftarrow_shape(expr axis, ex, em) =
+    vardef math_stacker_rightoverleftarrow_shape(expr axis, ex, em, rotate) =
         image (
             interim ahlength := ex/2;
             drawdoublearrows
@@ -110,14 +112,11 @@
             withcolor
                 OverlayLineColor ;
             setbounds currentpicture to unitsquare xysized(OverlayWidth,ex) ;
+            if rotate :
+                currentpicture := currentpicture rotated 180 ;
+            fi ;
         )
     enddef ;
-    vardef math_stacker_leftarrow_shape(expr axis, ex, em) =
-        math_stacker_arrow_shape(axis,ex,em)
-    enddef ;
-    vardef math_stacker_rightarrow_shape(expr axis, ex, em) =
-        math_stacker_arrow_shape(axis,ex,em) rotated 180
-    enddef ;
 
     % main handler
 
@@ -131,55 +130,55 @@
 \stopMPextensions
 
 \startuniqueMPgraphic{math:stacker:\number"FE3B4}{axis,ex,em}
-    math_stacker_draw_accent(math_stacker_overbracket_shape) ;
+    math_stacker_draw_accent(math_stacker_bracket_shape(OverlayHeight,false)) ;
 \stopuniqueMPgraphic
 
 \startuniqueMPgraphic{math:stacker:\number"FE3B5}{axis,ex,em}
-    math_stacker_draw_accent(math_stacker_underbracket_shape) ;
+    math_stacker_draw_accent(math_stacker_bracket_shape(OverlayDepth,true)) ;
 \stopuniqueMPgraphic
 
 \startuniqueMPgraphic{math:stacker:\number"FE3DC}{axis,ex,em}
-    math_stacker_draw_accent(math_stacker_overparent_shape) ;
+    math_stacker_draw_accent(math_stacker_parent_shape(OverlayHeight,false)) ;
 \stopuniqueMPgraphic
 
 \startuniqueMPgraphic{math:stacker:\number"FE3DD}{axis,ex,em}
-    math_stacker_draw_accent(math_stacker_underparent_shape) ;
+    math_stacker_draw_accent(math_stacker_parent_shape(OverlayDepth,true)) ;
 \stopuniqueMPgraphic
 
 \startuniqueMPgraphic{math:stacker:\number"FE3DE}{axis,ex,em}
-    math_stacker_draw_accent(math_stacker_overbrace_shape) ;
+    math_stacker_draw_accent(math_stacker_brace_shape(OverlayHeight,false)) ;
 \stopuniqueMPgraphic
 
 \startuniqueMPgraphic{math:stacker:\number"FE3DF}{axis,ex,em}
-    math_stacker_draw_accent(math_stacker_underbrace_shape) ;
+    math_stacker_draw_accent(math_stacker_brace_shape(OverlayDepth,true)) ;
 \stopuniqueMPgraphic
 
 \startuniqueMPgraphic{math:stacker:\number"FE33E}{axis,ex,em}
-    math_stacker_draw_accent(math_stacker_overbar_shape) ;
+    math_stacker_draw_accent(math_stacker_bar_shape(false)) ;
 \stopuniqueMPgraphic
 
 \startuniqueMPgraphic{math:stacker:\number"FE33F}{axis,ex,em}
-    math_stacker_draw_accent(math_stacker_underbar_shape) ;
+    math_stacker_draw_accent(math_stacker_bar_shape(true)) ;
 \stopuniqueMPgraphic
 
 \startuniqueMPgraphic{math:stacker:\number"2190}{axis,ex,em}
-    math_stacker_draw_arrow(math_stacker_leftarrow_shape(\MPvar{axis},\MPvar{ex},\MPvar{em})) ;
+    math_stacker_draw_arrow(math_stacker_arrow_shape(\MPvar{axis},\MPvar{ex},\MPvar{em},false)) ;
 \stopuniqueMPgraphic
 
 \startuniqueMPgraphic{math:stacker:\number"2192}{axis,ex,em}
-    math_stacker_draw_arrow(math_stacker_rightarrow_shape(\MPvar{axis},\MPvar{ex},\MPvar{em})) ;
+    math_stacker_draw_arrow(math_stacker_arrow_shape(\MPvar{axis},\MPvar{ex},\MPvar{em},true)) ;
 \stopuniqueMPgraphic
 
 \startuniqueMPgraphic{math:stacker:\number"2194}{axis,ex,em}
-    math_stacker_draw_arrow(math_stacker_leftrightarrow_shape(\MPvar{axis},\MPvar{ex},\MPvar{em})) ;
+    math_stacker_draw_arrow(math_stacker_leftrightarrow_shape(\MPvar{axis},\MPvar{ex},\MPvar{em},false)) ;
 \stopuniqueMPgraphic
 
 \startuniqueMPgraphic{math:stacker:\number"27F7}{axis,ex,em}
-    math_stacker_draw_arrow(math_stacker_leftrightarrow_shape(\MPvar{axis},\MPvar{ex},\MPvar{em})) ;
+    math_stacker_draw_arrow(math_stacker_leftrightarrow_shape(\MPvar{axis},\MPvar{ex},\MPvar{em},false)) ;
 \stopuniqueMPgraphic
 
 \startuniqueMPgraphic{math:stacker:\number"21C4}{axis,ex,em}
-    math_stacker_draw_arrow(math_stacker_rightoverleftarrow_shape(\MPvar{axis},\MPvar{ex},\MPvar{em})) ;
+    math_stacker_draw_arrow(math_stacker_rightoverleftarrow_shape(\MPvar{axis},\MPvar{ex},\MPvar{em},false)) ;
 \stopuniqueMPgraphic
 
 %D Radicals:
@@ -202,9 +201,46 @@
         withcolor OverlayLineColor ;
 \stopuniqueMPgraphic
 
-% \setupmathstackers
-%   [vfenced]
-%   [color=darkred,
-%    alternative=mp]
-
-\endinput
+\continueifinputfile{meta-imp-mat.mkiv}
+
+\setupmathstackers [both]   [color=darkred,alternative=mp]
+\setupmathstackers [top]    [color=darkred,alternative=mp]
+\setupmathstackers [bottom] [color=darkred,alternative=mp]
+
+\startTEXpage[offset=10pt]
+
+$
+    \overbracket   {a+b+c+d} \quad
+    \underbracket  {a+b+c+d} \quad
+    \doublebracket {a+b+c+d}
+$
+\blank[2*big]
+$
+    \overparent   {a+b+c+d} \quad
+    \underparent  {a+b+c+d} \quad
+    \doubleparent {a+b+c+d}
+$
+\blank[2*big]
+$
+    \overbrace   {a+b+c+d} \quad
+    \underbrace  {a+b+c+d} \quad
+    \doublebrace {a+b+c+d}
+$
+\blank[2*big]
+$
+    \overbar   {a+b+c+d} \quad
+    \underbar  {a+b+c+d} \quad
+    \doublebar {a+b+c+d}
+$
+\blank[2*big]
+$
+    \overleftarrow  {a+b+c+d} \quad
+    \overrightarrow {a+b+c+d}
+$
+\blank[2*big]
+$
+    \underleftarrow  {a+b+c+d} \quad
+    \underrightarrow {a+b+c+d}
+$
+
+\stopTEXpage
diff --git a/tex/context/base/mkiv/meta-ini.mkiv b/tex/context/base/mkiv/meta-ini.mkiv
index 5fc89e2f6..61e3523e6 100644
--- a/tex/context/base/mkiv/meta-ini.mkiv
+++ b/tex/context/base/mkiv/meta-ini.mkiv
@@ -1481,6 +1481,12 @@
     \fi
 \to \everysetupMPgraphics
 
+%D Some more helpers (see \type {meta-grd.mkiv} for an example of usage):
+
+\def\MPdpar#1#2{\the\dimexpr#1#2\relax\empty}
+\def\MPnpar#1#2{\the\numexpr#1#2\relax\empty}
+\def\MPspar#1#2{"#1#2"}
+
 %D Done.
 
 \protect \endinput
diff --git a/tex/context/base/mkiv/mult-aux.mkiv b/tex/context/base/mkiv/mult-aux.mkiv
index 96609c4f0..a1aecc354 100644
--- a/tex/context/base/mkiv/mult-aux.mkiv
+++ b/tex/context/base/mkiv/mult-aux.mkiv
@@ -802,10 +802,11 @@
 
 \letvalue\??dummy\empty
 
-           \def\dummyparameter      #1{\begincsname\??dummy#1\endcsname}
-           \def\directdummyparameter#1{\begincsname\??dummy#1\endcsname}
-\unexpanded\def\setdummyparameter   #1{\expandafter\def\csname\??dummy#1\endcsname}
-\unexpanded\def\letdummyparameter   #1{\expandafter\let\csname\??dummy#1\endcsname}
+           \def\dummyparameter           #1{\begincsname\??dummy#1\endcsname}
+           \def\directdummyparameter     #1{\begincsname\??dummy#1\endcsname}
+\unexpanded\def\setdummyparameter        #1{\expandafter\def\csname\??dummy#1\endcsname}
+\unexpanded\def\setexpandeddummyparameter#1{\expandafter\edef\csname\??dummy#1\endcsname}
+\unexpanded\def\letdummyparameter        #1{\expandafter\let\csname\??dummy#1\endcsname}
 
 % \unexpanded\def\getdummyparameters
 %   {\mult_interfaces_get_parameters\??dummy}
diff --git a/tex/context/base/mkiv/mult-low.lua b/tex/context/base/mkiv/mult-low.lua
index 84b4189dc..cfe0c59e2 100644
--- a/tex/context/base/mkiv/mult-low.lua
+++ b/tex/context/base/mkiv/mult-low.lua
@@ -294,7 +294,7 @@ return {
         --
         "getparameters", "geteparameters", "getgparameters", "getxparameters", "forgetparameters", "copyparameters",
         --
-        "getdummyparameters", "dummyparameter", "directdummyparameter", "setdummyparameter", "letdummyparameter",
+        "getdummyparameters", "dummyparameter", "directdummyparameter", "setdummyparameter", "letdummyparameter", "setexpandeddummyparameter",
         "usedummystyleandcolor", "usedummystyleparameter", "usedummycolorparameter",
         --
         "processcommalist", "processcommacommand", "quitcommalist", "quitprevcommalist",
diff --git a/tex/context/base/mkiv/status-files.pdf b/tex/context/base/mkiv/status-files.pdf
index 6e2441929..ee53ac2b5 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 13610af00..8c98172e1 100644
--- a/tex/context/base/mkiv/status-lua.pdf
+++ b/tex/context/base/mkiv/status-lua.pdf
diff --git a/tex/context/base/mkiv/trac-log.lua b/tex/context/base/mkiv/trac-log.lua
index b0da12715..1471bd4c7 100644
--- a/tex/context/base/mkiv/trac-log.lua
+++ b/tex/context/base/mkiv/trac-log.lua
@@ -18,7 +18,6 @@ local datetime = os.date
 local openfile = io.open
 
 local runningtex = tex and (tex.jobname or tex.formatname)
-
 -- local write_nl = texio and texio.write_nl or print
 -- local write    = texio and texio.write    or io.write
 
diff --git a/tex/context/base/mkiv/util-str.lua b/tex/context/base/mkiv/util-str.lua
index 9da0c6a2f..c8cc1742b 100644
--- a/tex/context/base/mkiv/util-str.lua
+++ b/tex/context/base/mkiv/util-str.lua
@@ -296,7 +296,7 @@ end
 --
 -- integer            %...i   number
 -- integer            %...d   number
--- unsigned           %...u   number -- no tused
+-- unsigned           %...u   number -- not used
 -- character          %...c   number
 -- hexadecimal        %...x   number
 -- HEXADECIMAL        %...X   number