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if not modules then modules = { } end modules ['typo-bld'] = { -- was node-par
version = 1.001,
comment = "companion to typo-bld.mkiv",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
local insert, remove = table.insert, table.remove
local builders, nodes, node = builders, nodes, node
builders.paragraphs = builders.paragraphs or { }
local parbuilders = builders.paragraphs
parbuilders.constructors = parbuilders.constructors or { }
local constructors = parbuilders.constructors
constructors.names = constructors.names or { }
local names = constructors.names
constructors.numbers = constructors.numbers or { }
local numbers = constructors.numbers
constructors.methods = constructors.methods or { }
local methods = constructors.methods
local a_parbuilder = attributes.numbers['parbuilder'] or 999 -- why 999
constructors.attribute = a_parbuilder
local unsetvalue = attributes.unsetvalue
local texsetattribute = tex.setattribute
local texnest = tex.nest
local nodepool = nodes.pool
local new_baselineskip = nodepool.baselineskip
local new_lineskip = nodepool.lineskip
local insert_node_before = node.insert_before
local hpack_node = node.hpack
local starttiming = statistics.starttiming
local stoptiming = statistics.stoptiming
storage.register("builders/paragraphs/constructors/names", names, "builders.paragraphs.constructors.names")
storage.register("builders/paragraphs/constructors/numbers", numbers, "builders.paragraphs.constructors.numbers")
local report_parbuilders = logs.reporter("parbuilders")
local mainconstructor = nil -- not stored in format
local nofconstructors = 0
local stack = { }
function constructors.define(name)
nofconstructors = nofconstructors + 1
names[nofconstructors] = name
numbers[name] = nofconstructors
end
function constructors.set(name) --- will go
if name then
mainconstructor = numbers[name] or unsetvalue
else
mainconstructor = stack[#stack] or unsetvalue
end
texsetattribute(a_parbuilder,mainconstructor)
if mainconstructor ~= unsetvalue then
constructors.enable()
end
end
function constructors.start(name)
local number = numbers[name]
insert(stack,number)
mainconstructor = number or unsetvalue
texsetattribute(a_parbuilder,mainconstructor)
if mainconstructor ~= unsetvalue then
constructors.enable()
end
-- report_parbuilders("start %a",name)
end
function constructors.stop()
remove(stack)
mainconstructor = stack[#stack] or unsetvalue
texsetattribute(a_parbuilder,mainconstructor)
if mainconstructor == unsetvalue then
constructors.disable()
end
-- report_parbuilders("stop")
end
-- return values:
--
-- true : tex will break itself
-- false : idem but dangerous
-- head : list of valid vmode nodes with last being hlist
function constructors.handler(head,followed_by_display)
if type(head) == "boolean" then
return head
else
local attribute = head[a_parbuilder] -- or mainconstructor
if attribute then
local method = names[attribute]
if method then
local handler = methods[method]
if handler then
return handler(head,followed_by_display)
else
report_parbuilders("contructor method %a is not defined",tostring(method))
return true -- let tex break
end
end
end
return true -- let tex break
end
end
-- just for testing
function constructors.methods.default(head,followed_by_display)
return true -- let tex break
end
-- also for testing (now also surrounding spacing done)
function builders.paragraphs.constructors.methods.oneline(head,followed_by_display)
-- when needed we will turn this into a helper
local t = texnest[texnest.ptr]
local h = hpack_node(head)
local d = tex.baselineskip.width - t.prevdepth - h.height
t.prevdepth = h.depth
t.prevgraf = 1
if d < tex.lineskiplimit then
return insert_node_before(h,h,new_lineskip(tex.lineskip))
else
return insert_node_before(h,h,new_baselineskip(d))
end
end
-- It makes no sense to have a sequence here as we already have
-- pre and post hooks and only one parbuilder makes sense, so no:
--
-- local actions = nodes.tasks.actions("parbuilders")
--
-- yet ... maybe some day.
local actions = constructors.handler
local enabled = false
local function processor(head,followed_by_display)
-- todo: not again in otr so we need to flag
if enabled then
starttiming(parbuilders)
local head = actions(head,followed_by_display)
stoptiming(parbuilders)
return head
else
return true -- let tex do the work
end
end
function constructors.enable()
enabled = true
end
function constructors.disable()
enabled = false
end
callbacks.register('linebreak_filter', processor, "breaking paragraps into lines")
statistics.register("linebreak processing time", function()
return statistics.elapsedseconds(parbuilders)
end)
-- interface
commands.defineparbuilder = constructors.define
commands.startparbuilder = constructors.start
commands.stopparbuilder = constructors.stop
commands.setparbuilder = constructors.set
commands.enableparbuilder = constructors.enable
commands.disableparbuilder = constructors.disable
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