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-rw-r--r--tex/context/base/math-act.lua808
1 files changed, 404 insertions, 404 deletions
diff --git a/tex/context/base/math-act.lua b/tex/context/base/math-act.lua
index 875e200c1..4f9b3b7e8 100644
--- a/tex/context/base/math-act.lua
+++ b/tex/context/base/math-act.lua
@@ -1,404 +1,404 @@
-if not modules then modules = { } end modules ['math-act'] = {
- version = 1.001,
- comment = "companion to math-ini.mkiv",
- author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
- copyright = "PRAGMA ADE / ConTeXt Development Team",
- license = "see context related readme files"
-}
-
--- Here we tweak some font properties (if needed).
-
-local type, next = type, next
-local fastcopy = table.fastcopy
-
-local trace_defining = false trackers.register("math.defining", function(v) trace_defining = v end)
-local report_math = logs.reporter("mathematics","initializing")
-
-local context = context
-local commands = commands
-local mathematics = mathematics
-local texdimen = tex.dimen
-local abs = math.abs
-
-local sequencers = utilities.sequencers
-local appendgroup = sequencers.appendgroup
-local appendaction = sequencers.appendaction
-
-local mathfontparameteractions = sequencers.new {
- name = "mathparameters",
- arguments = "target,original",
-}
-
-appendgroup("mathparameters","before") -- user
-appendgroup("mathparameters","system") -- private
-appendgroup("mathparameters","after" ) -- user
-
-function fonts.constructors.assignmathparameters(original,target)
- local runner = mathfontparameteractions.runner
- if runner then
- runner(original,target)
- end
-end
-
-function mathematics.initializeparameters(target,original)
- local mathparameters = original.mathparameters
- if mathparameters and next(mathparameters) then
- target.mathparameters = mathematics.dimensions(mathparameters)
- end
-end
-
-sequencers.appendaction("mathparameters","system","mathematics.initializeparameters")
-
-local how = {
- -- RadicalKernBeforeDegree = "horizontal",
- -- RadicalKernAfterDegree = "horizontal",
- ScriptPercentScaleDown = "unscaled",
- ScriptScriptPercentScaleDown = "unscaled",
- RadicalDegreeBottomRaisePercent = "unscaled"
-}
-
-function mathematics.scaleparameters(target,original)
- if not target.properties.math_is_scaled then
- local mathparameters = target.mathparameters
- if mathparameters and next(mathparameters) then
- local parameters = target.parameters
- local factor = parameters.factor
- local hfactor = parameters.hfactor
- local vfactor = parameters.vfactor
- for name, value in next, mathparameters do
- local h = how[name]
- if h == "unscaled" then
- -- kept
- elseif h == "horizontal" then
- value = value * hfactor
- elseif h == "vertical"then
- value = value * vfactor
- else
- value = value * factor
- end
- mathparameters[name] = value
- end
- end
- target.properties.math_is_scaled = true
- end
-end
-
-sequencers.appendaction("mathparameters","system","mathematics.scaleparameters")
-
-function mathematics.checkaccentbaseheight(target,original)
- local mathparameters = target.mathparameters
- if mathparameters and mathparameters.AccentBaseHeight == 0 then
- mathparameters.AccentBaseHeight = target.parameters.x_height -- needs checking
- end
-end
-
-sequencers.appendaction("mathparameters","system","mathematics.checkaccentbaseheight") -- should go in lfg instead
-
-function mathematics.checkprivateparameters(target,original)
- local mathparameters = target.mathparameters
- if mathparameters then
- local parameters = target.parameters
- if parameters then
- if not mathparameters.FractionDelimiterSize then
- mathparameters.FractionDelimiterSize = 1.01 * parameters.size
- end
- if not mathparameters.FractionDelimiterDisplayStyleSize then
- mathparameters.FractionDelimiterDisplayStyleSize = 2.40 * parameters.size
- end
- elseif target.properties then
- report_math("no parameters in font %a",target.properties.fullname or "?")
- else
- report_math("no parameters and properties in font")
- end
- end
-end
-
-sequencers.appendaction("mathparameters","system","mathematics.checkprivateparameters")
-
-function mathematics.overloadparameters(target,original)
- local mathparameters = target.mathparameters
- if mathparameters and next(mathparameters) then
- local goodies = target.goodies
- if goodies then
- for i=1,#goodies do
- local goodie = goodies[i]
- local mathematics = goodie.mathematics
- local parameters = mathematics and mathematics.parameters
- if parameters then
- if trace_defining then
- report_math("overloading math parameters in %a @ %p",target.properties.fullname,target.parameters.size)
- end
- for name, value in next, parameters do
- local tvalue = type(value)
- if tvalue == "string" then
- report_math("comment for math parameter %a: %s",name,value)
- else
- local oldvalue = mathparameters[name]
- local newvalue = oldvalue
- if oldvalue then
- if tvalue == "number" then
- newvalue = value
- elseif tvalue == "function" then
- newvalue = value(oldvalue,target,original)
- elseif not tvalue then
- newvalue = nil
- end
- if trace_defining and oldvalue ~= newvalue then
- report_math("overloading math parameter %a: %S => %S",name,oldvalue,newvalue)
- end
- else
- report_math("invalid math parameter %a",name)
- end
- mathparameters[name] = newvalue
- end
- end
- end
- end
- end
- end
-end
-
-sequencers.appendaction("mathparameters","system","mathematics.overloadparameters")
-
-local function applytweaks(when,target,original)
- local goodies = original.goodies
- if goodies then
- for i=1,#goodies do
- local goodie = goodies[i]
- local mathematics = goodie.mathematics
- local tweaks = mathematics and mathematics.tweaks
- if tweaks then
- tweaks = tweaks[when]
- if tweaks then
- if trace_defining then
- report_math("tweaking math of %a @ %p (%s)",target.properties.fullname,target.parameters.size,when)
- end
- for i=1,#tweaks do
- local tweak= tweaks[i]
- local tvalue = type(tweak)
- if tvalue == "function" then
- tweak(target,original)
- end
- end
- end
- end
- end
- end
-end
-
-function mathematics.tweakbeforecopyingfont(target,original)
- local mathparameters = target.mathparameters -- why not hasmath
- if mathparameters then
- applytweaks("beforecopying",target,original)
- end
-end
-
-function mathematics.tweakaftercopyingfont(target,original)
- local mathparameters = target.mathparameters -- why not hasmath
- if mathparameters then
- applytweaks("aftercopying",target,original)
- end
-end
-
-sequencers.appendaction("beforecopyingcharacters","system","mathematics.tweakbeforecopyingfont")
-sequencers.appendaction("aftercopyingcharacters", "system","mathematics.tweakaftercopyingfont")
-
-function mathematics.overloaddimensions(target,original,set)
- local goodies = target.goodies
- if goodies then
- for i=1,#goodies do
- local goodie = goodies[i]
- local mathematics = goodie.mathematics
- local dimensions = mathematics and mathematics.dimensions
- if dimensions then
- if trace_defining then
- report_math("overloading dimensions in %a @ %p",target.properties.fullname,target.parameters.size)
- end
- local characters = target.characters
- local parameters = target.parameters
- local factor = parameters.factor
- local hfactor = parameters.hfactor
- local vfactor = parameters.vfactor
- local addprivate = fonts.helpers.addprivate
- local function overload(dimensions)
- for unicode, data in next, dimensions do
- local character = characters[unicode]
- if character then
- --
- local width = data.width
- local height = data.height
- local depth = data.depth
- if trace_defining and (width or height or depth) then
- report_math("overloading dimensions of %C, width %a, height %a, depth %a",unicode,width,height,depth)
- end
- if width then character.width = width * hfactor end
- if height then character.height = height * vfactor end
- if depth then character.depth = depth * vfactor end
- --
- local xoffset = data.xoffset
- local yoffset = data.yoffset
- if xoffset then
- xoffset = { "right", xoffset * hfactor }
- end
- if yoffset then
- yoffset = { "down", -yoffset * vfactor }
- end
- if xoffset or yoffset then
- local slot = { "slot", 1, addprivate(target,nil,fastcopy(character)) }
- if xoffset and yoffset then
- character.commands = { xoffset, yoffset, slot }
- elseif xoffset then
- character.commands = { xoffset, slot }
- else
- character.commands = { yoffset, slot }
- end
- character.index = nil
- end
- elseif trace_defining then
- report_math("no overloading dimensions of %C, not in font",unicode)
- end
- end
- end
- if set == nil then
- set = { "default" }
- end
- if set == "all" or set == true then
- for name, set in next, dimensions do
- overload(set)
- end
- else
- if type(set) == "string" then
- set = utilities.parsers.settings_to_array(set)
- end
- if type(set) == "table" then
- for i=1,#set do
- local d = dimensions[set[i]]
- if d then
- overload(d)
- end
- end
- end
- end
- end
- end
- end
-end
-
-sequencers.appendaction("aftercopyingcharacters", "system","mathematics.overloaddimensions")
-
--- a couple of predefined tewaks:
-
-local tweaks = { }
-mathematics.tweaks = tweaks
-
-function tweaks.fixbadprime(target,original)
- target.characters[0xFE325] = target.characters[0x2032]
-end
-
--- helpers
-
-local setmetatableindex = table.setmetatableindex
-local family_font = node.family_font
-
-local fontcharacters = fonts.hashes.characters
-local extensibles = utilities.storage.allocate()
-fonts.hashes.extensibles = extensibles
-
-local chardata = characters.data
-local extensibles = mathematics.extensibles
-
--- we use numbers at the tex end (otherwise we could stick to chars)
-
-local e_left = extensibles.left
-local e_right = extensibles.right
-local e_horizontal = extensibles.horizontal
-local e_vertical = extensibles.vertical
-local e_mixed = extensibles.mixed
-local e_unknown = extensibles.unknown
-
-local unknown = { e_unknown, false, false }
-
-local function extensiblecode(font,unicode)
- local characters = fontcharacters[font]
- local character = characters[unicode]
- if not character then
- return unknown
- end
- local code = unicode
- local next = character.next
- while next do
- code = next
- character = characters[next]
- next = character.next
- end
- local char = chardata[unicode]
- local mathextensible = char and char.mathextensible
- if character.horiz_variants then
- if character.vert_variants then
- return { e_mixed, code, character }
- else
- local e = mathextensible and extensibles[mathextensible]
- return e and { e, code, character } or unknown
- end
- elseif character.vert_variants then
- local e = mathextensible and extensibles[mathextensible]
- return e and { e, code, character } or unknown
- else
- return unknown
- end
-end
-
-setmetatableindex(extensibles,function(extensibles,font)
- local codes = { }
- setmetatableindex(codes, function(codes,unicode)
- local status = extensiblecode(font,unicode)
- codes[unicode] = status
- return status
- end)
- extensibles[font] = codes
- return codes
-end)
-
-function mathematics.extensiblecode(family,unicode)
- return extensibles[family_font(family or 0)][unicode][1]
-end
-
-function commands.extensiblecode(family,unicode)
- context(extensibles[family_font(family or 0)][unicode][1])
-end
-
--- left : [head] ...
--- right : ... [head]
--- horizontal : [head] ... [head]
---
--- abs(right["start"] - right["end"]) | right.advance | characters[right.glyph].width
-
-function commands.horizontalcode(family,unicode)
- local font = family_font(family or 0)
- local data = extensibles[font][unicode]
- local kind = data[1]
- if kind == e_left then
- local charlist = data[3].horiz_variants
- local characters = fontcharacters[font]
- local left = charlist[1]
- texdimen.scratchleftoffset = abs((left["start"] or 0) - (left["end"] or 0))
- texdimen.scratchrightoffset = 0
- elseif kind == e_right then
- local charlist = data[3].horiz_variants
- local characters = fontcharacters[font]
- local right = charlist[#charlist]
- texdimen.scratchleftoffset = 0
- texdimen.scratchrightoffset = abs((right["start"] or 0) - (right["end"] or 0))
- elseif kind == e_horizontal then
- local charlist = data[3].horiz_variants
- local characters = fontcharacters[font]
- local left = charlist[1]
- local right = charlist[#charlist]
- texdimen.scratchleftoffset = abs((left["start"] or 0) - (left["end"] or 0))
- texdimen.scratchrightoffset = abs((right["start"] or 0) - (right["end"] or 0))
- else
- texdimen.scratchleftoffset = 0
- texdimen.scratchrightoffset = 0
- end
- context(kind)
-end
+if not modules then modules = { } end modules ['math-act'] = {
+ version = 1.001,
+ comment = "companion to math-ini.mkiv",
+ author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
+ copyright = "PRAGMA ADE / ConTeXt Development Team",
+ license = "see context related readme files"
+}
+
+-- Here we tweak some font properties (if needed).
+
+local type, next = type, next
+local fastcopy = table.fastcopy
+
+local trace_defining = false trackers.register("math.defining", function(v) trace_defining = v end)
+local report_math = logs.reporter("mathematics","initializing")
+
+local context = context
+local commands = commands
+local mathematics = mathematics
+local texdimen = tex.dimen
+local abs = math.abs
+
+local sequencers = utilities.sequencers
+local appendgroup = sequencers.appendgroup
+local appendaction = sequencers.appendaction
+
+local mathfontparameteractions = sequencers.new {
+ name = "mathparameters",
+ arguments = "target,original",
+}
+
+appendgroup("mathparameters","before") -- user
+appendgroup("mathparameters","system") -- private
+appendgroup("mathparameters","after" ) -- user
+
+function fonts.constructors.assignmathparameters(original,target)
+ local runner = mathfontparameteractions.runner
+ if runner then
+ runner(original,target)
+ end
+end
+
+function mathematics.initializeparameters(target,original)
+ local mathparameters = original.mathparameters
+ if mathparameters and next(mathparameters) then
+ target.mathparameters = mathematics.dimensions(mathparameters)
+ end
+end
+
+sequencers.appendaction("mathparameters","system","mathematics.initializeparameters")
+
+local how = {
+ -- RadicalKernBeforeDegree = "horizontal",
+ -- RadicalKernAfterDegree = "horizontal",
+ ScriptPercentScaleDown = "unscaled",
+ ScriptScriptPercentScaleDown = "unscaled",
+ RadicalDegreeBottomRaisePercent = "unscaled"
+}
+
+function mathematics.scaleparameters(target,original)
+ if not target.properties.math_is_scaled then
+ local mathparameters = target.mathparameters
+ if mathparameters and next(mathparameters) then
+ local parameters = target.parameters
+ local factor = parameters.factor
+ local hfactor = parameters.hfactor
+ local vfactor = parameters.vfactor
+ for name, value in next, mathparameters do
+ local h = how[name]
+ if h == "unscaled" then
+ -- kept
+ elseif h == "horizontal" then
+ value = value * hfactor
+ elseif h == "vertical"then
+ value = value * vfactor
+ else
+ value = value * factor
+ end
+ mathparameters[name] = value
+ end
+ end
+ target.properties.math_is_scaled = true
+ end
+end
+
+sequencers.appendaction("mathparameters","system","mathematics.scaleparameters")
+
+function mathematics.checkaccentbaseheight(target,original)
+ local mathparameters = target.mathparameters
+ if mathparameters and mathparameters.AccentBaseHeight == 0 then
+ mathparameters.AccentBaseHeight = target.parameters.x_height -- needs checking
+ end
+end
+
+sequencers.appendaction("mathparameters","system","mathematics.checkaccentbaseheight") -- should go in lfg instead
+
+function mathematics.checkprivateparameters(target,original)
+ local mathparameters = target.mathparameters
+ if mathparameters then
+ local parameters = target.parameters
+ if parameters then
+ if not mathparameters.FractionDelimiterSize then
+ mathparameters.FractionDelimiterSize = 1.01 * parameters.size
+ end
+ if not mathparameters.FractionDelimiterDisplayStyleSize then
+ mathparameters.FractionDelimiterDisplayStyleSize = 2.40 * parameters.size
+ end
+ elseif target.properties then
+ report_math("no parameters in font %a",target.properties.fullname or "?")
+ else
+ report_math("no parameters and properties in font")
+ end
+ end
+end
+
+sequencers.appendaction("mathparameters","system","mathematics.checkprivateparameters")
+
+function mathematics.overloadparameters(target,original)
+ local mathparameters = target.mathparameters
+ if mathparameters and next(mathparameters) then
+ local goodies = target.goodies
+ if goodies then
+ for i=1,#goodies do
+ local goodie = goodies[i]
+ local mathematics = goodie.mathematics
+ local parameters = mathematics and mathematics.parameters
+ if parameters then
+ if trace_defining then
+ report_math("overloading math parameters in %a @ %p",target.properties.fullname,target.parameters.size)
+ end
+ for name, value in next, parameters do
+ local tvalue = type(value)
+ if tvalue == "string" then
+ report_math("comment for math parameter %a: %s",name,value)
+ else
+ local oldvalue = mathparameters[name]
+ local newvalue = oldvalue
+ if oldvalue then
+ if tvalue == "number" then
+ newvalue = value
+ elseif tvalue == "function" then
+ newvalue = value(oldvalue,target,original)
+ elseif not tvalue then
+ newvalue = nil
+ end
+ if trace_defining and oldvalue ~= newvalue then
+ report_math("overloading math parameter %a: %S => %S",name,oldvalue,newvalue)
+ end
+ else
+ report_math("invalid math parameter %a",name)
+ end
+ mathparameters[name] = newvalue
+ end
+ end
+ end
+ end
+ end
+ end
+end
+
+sequencers.appendaction("mathparameters","system","mathematics.overloadparameters")
+
+local function applytweaks(when,target,original)
+ local goodies = original.goodies
+ if goodies then
+ for i=1,#goodies do
+ local goodie = goodies[i]
+ local mathematics = goodie.mathematics
+ local tweaks = mathematics and mathematics.tweaks
+ if tweaks then
+ tweaks = tweaks[when]
+ if tweaks then
+ if trace_defining then
+ report_math("tweaking math of %a @ %p (%s)",target.properties.fullname,target.parameters.size,when)
+ end
+ for i=1,#tweaks do
+ local tweak= tweaks[i]
+ local tvalue = type(tweak)
+ if tvalue == "function" then
+ tweak(target,original)
+ end
+ end
+ end
+ end
+ end
+ end
+end
+
+function mathematics.tweakbeforecopyingfont(target,original)
+ local mathparameters = target.mathparameters -- why not hasmath
+ if mathparameters then
+ applytweaks("beforecopying",target,original)
+ end
+end
+
+function mathematics.tweakaftercopyingfont(target,original)
+ local mathparameters = target.mathparameters -- why not hasmath
+ if mathparameters then
+ applytweaks("aftercopying",target,original)
+ end
+end
+
+sequencers.appendaction("beforecopyingcharacters","system","mathematics.tweakbeforecopyingfont")
+sequencers.appendaction("aftercopyingcharacters", "system","mathematics.tweakaftercopyingfont")
+
+function mathematics.overloaddimensions(target,original,set)
+ local goodies = target.goodies
+ if goodies then
+ for i=1,#goodies do
+ local goodie = goodies[i]
+ local mathematics = goodie.mathematics
+ local dimensions = mathematics and mathematics.dimensions
+ if dimensions then
+ if trace_defining then
+ report_math("overloading dimensions in %a @ %p",target.properties.fullname,target.parameters.size)
+ end
+ local characters = target.characters
+ local parameters = target.parameters
+ local factor = parameters.factor
+ local hfactor = parameters.hfactor
+ local vfactor = parameters.vfactor
+ local addprivate = fonts.helpers.addprivate
+ local function overload(dimensions)
+ for unicode, data in next, dimensions do
+ local character = characters[unicode]
+ if character then
+ --
+ local width = data.width
+ local height = data.height
+ local depth = data.depth
+ if trace_defining and (width or height or depth) then
+ report_math("overloading dimensions of %C, width %a, height %a, depth %a",unicode,width,height,depth)
+ end
+ if width then character.width = width * hfactor end
+ if height then character.height = height * vfactor end
+ if depth then character.depth = depth * vfactor end
+ --
+ local xoffset = data.xoffset
+ local yoffset = data.yoffset
+ if xoffset then
+ xoffset = { "right", xoffset * hfactor }
+ end
+ if yoffset then
+ yoffset = { "down", -yoffset * vfactor }
+ end
+ if xoffset or yoffset then
+ local slot = { "slot", 1, addprivate(target,nil,fastcopy(character)) }
+ if xoffset and yoffset then
+ character.commands = { xoffset, yoffset, slot }
+ elseif xoffset then
+ character.commands = { xoffset, slot }
+ else
+ character.commands = { yoffset, slot }
+ end
+ character.index = nil
+ end
+ elseif trace_defining then
+ report_math("no overloading dimensions of %C, not in font",unicode)
+ end
+ end
+ end
+ if set == nil then
+ set = { "default" }
+ end
+ if set == "all" or set == true then
+ for name, set in next, dimensions do
+ overload(set)
+ end
+ else
+ if type(set) == "string" then
+ set = utilities.parsers.settings_to_array(set)
+ end
+ if type(set) == "table" then
+ for i=1,#set do
+ local d = dimensions[set[i]]
+ if d then
+ overload(d)
+ end
+ end
+ end
+ end
+ end
+ end
+ end
+end
+
+sequencers.appendaction("aftercopyingcharacters", "system","mathematics.overloaddimensions")
+
+-- a couple of predefined tewaks:
+
+local tweaks = { }
+mathematics.tweaks = tweaks
+
+function tweaks.fixbadprime(target,original)
+ target.characters[0xFE325] = target.characters[0x2032]
+end
+
+-- helpers
+
+local setmetatableindex = table.setmetatableindex
+local family_font = node.family_font
+
+local fontcharacters = fonts.hashes.characters
+local extensibles = utilities.storage.allocate()
+fonts.hashes.extensibles = extensibles
+
+local chardata = characters.data
+local extensibles = mathematics.extensibles
+
+-- we use numbers at the tex end (otherwise we could stick to chars)
+
+local e_left = extensibles.left
+local e_right = extensibles.right
+local e_horizontal = extensibles.horizontal
+local e_vertical = extensibles.vertical
+local e_mixed = extensibles.mixed
+local e_unknown = extensibles.unknown
+
+local unknown = { e_unknown, false, false }
+
+local function extensiblecode(font,unicode)
+ local characters = fontcharacters[font]
+ local character = characters[unicode]
+ if not character then
+ return unknown
+ end
+ local code = unicode
+ local next = character.next
+ while next do
+ code = next
+ character = characters[next]
+ next = character.next
+ end
+ local char = chardata[unicode]
+ local mathextensible = char and char.mathextensible
+ if character.horiz_variants then
+ if character.vert_variants then
+ return { e_mixed, code, character }
+ else
+ local e = mathextensible and extensibles[mathextensible]
+ return e and { e, code, character } or unknown
+ end
+ elseif character.vert_variants then
+ local e = mathextensible and extensibles[mathextensible]
+ return e and { e, code, character } or unknown
+ else
+ return unknown
+ end
+end
+
+setmetatableindex(extensibles,function(extensibles,font)
+ local codes = { }
+ setmetatableindex(codes, function(codes,unicode)
+ local status = extensiblecode(font,unicode)
+ codes[unicode] = status
+ return status
+ end)
+ extensibles[font] = codes
+ return codes
+end)
+
+function mathematics.extensiblecode(family,unicode)
+ return extensibles[family_font(family or 0)][unicode][1]
+end
+
+function commands.extensiblecode(family,unicode)
+ context(extensibles[family_font(family or 0)][unicode][1])
+end
+
+-- left : [head] ...
+-- right : ... [head]
+-- horizontal : [head] ... [head]
+--
+-- abs(right["start"] - right["end"]) | right.advance | characters[right.glyph].width
+
+function commands.horizontalcode(family,unicode)
+ local font = family_font(family or 0)
+ local data = extensibles[font][unicode]
+ local kind = data[1]
+ if kind == e_left then
+ local charlist = data[3].horiz_variants
+ local characters = fontcharacters[font]
+ local left = charlist[1]
+ texdimen.scratchleftoffset = abs((left["start"] or 0) - (left["end"] or 0))
+ texdimen.scratchrightoffset = 0
+ elseif kind == e_right then
+ local charlist = data[3].horiz_variants
+ local characters = fontcharacters[font]
+ local right = charlist[#charlist]
+ texdimen.scratchleftoffset = 0
+ texdimen.scratchrightoffset = abs((right["start"] or 0) - (right["end"] or 0))
+ elseif kind == e_horizontal then
+ local charlist = data[3].horiz_variants
+ local characters = fontcharacters[font]
+ local left = charlist[1]
+ local right = charlist[#charlist]
+ texdimen.scratchleftoffset = abs((left["start"] or 0) - (left["end"] or 0))
+ texdimen.scratchrightoffset = abs((right["start"] or 0) - (right["end"] or 0))
+ else
+ texdimen.scratchleftoffset = 0
+ texdimen.scratchrightoffset = 0
+ end
+ context(kind)
+end