if not modules then modules = { } end modules ['node-seq'] = {
version = 1.001,
comment = "companion to node-ini.tex",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
--[[ldx--
Here we implement a mechanism for chaining the special functions
that we use in to deal with mode list processing. We
assume that namespaces for the functions are used, but for speed we
use locals to refer to them when compiling the chain.
--ldx]]--
local format, gsub, concat, gmatch = string.format, string.gsub, table.concat, string.gmatch
sequencer = sequencer or { }
local function validaction(action)
local g = _G
for str in gmatch(action,"[^%.]+") do
g = g[str]
if not g then
return false
end
end
return true
end
function sequencer.reset()
return {
list = { },
order = { },
kind = { },
}
end
function sequencer.prependgroup(t,group,where)
local list, order = t.list, t.order
table.remove_value(order,group)
table.insert_before_value(order,where,group)
list[group] = { }
end
function sequencer.appendgroup(t,group,where)
local list, order = t.list, t.order
table.remove_value(order,group)
table.insert_after_value(order,where,group)
list[group] = { }
end
function sequencer.prependaction(t,group,action,where,kind,force)
local g = t.list[group]
if g and (force or validaction(action)) then
table.remove_value(g,action)
table.insert_before_value(g,where,action)
t.kind[action] = kind
end
end
function sequencer.appendaction(t,group,action,where,kind,force)
local g = t.list[group]
if g and (force or validaction(action)) then
table.remove_value(g,action)
table.insert_after_value(g,where,action)
t.kind[action] = kind
end
end
function sequencer.setkind(t,action,kind)
t.kind[action] = kind
end
function sequencer.removeaction(t,group,action,force)
local g = t.list[group]
if g and (force or validaction(action)) then
table.remove_value(g,action)
end
end
function sequencer.compile(t,compiler,n)
if type(t) == "string" then
-- already compiled
elseif compiler then
t = compiler(t,n)
else
t = sequencer.tostring(t,n)
end
return loadstring(t)()
end
local function localize(str)
return (gsub(str,"%.","_"))
end
local template = [[
%s
return function(...)
%s
end]]
function sequencer.tostring(t,n) -- n not done
local list, order, kind, vars, calls = t.list, t.order, t.kind, { }, { }
for i=1,#order do
local group = order[i]
local actions = list[group]
for i=1,#actions do
local action = actions[i]
local localized = localize(action)
vars [#vars +1] = format("local %s = %s", localized, action)
calls[#calls+1] = format(" %s(...) -- %s %i", localized, group, i)
end
end
return format(template,concat(vars,"\n"),concat(calls,"\n"))
end
-- we used to deal with tail as well but now that the lists are always
-- double linked and the kernel function no longer expect tail as
-- argument we stick to head and done (done can probably also go
-- as luatex deals with return values efficiently now .. in the
-- past there was some copying involved, but no longer)
local template = [[
%s
return function(head%s)
local ok, done = false, false
%s
return head, done
end]]
function sequencer.nodeprocessor(t,n)
local list, order, kind, vars, calls, args = t.list, t.order, t.kind, { }, { }, nil
if n == 0 then
args = ""
elseif n == 1 then
args = ",one"
elseif n == 2 then
args = ",one,two"
else
args = ",..."
end
for i=1,#order do
local group = order[i]
local actions = list[group]
for i=1,#actions do
local action = actions[i]
local localized = localize(action)
vars[#vars+1] = format("local %s = %s",localized,action)
if kind[action] == "nohead" then
calls[#calls+1] = format(" ok = %s(head%s) done = done or ok -- %s %i",localized,args,group,i)
else
calls[#calls+1] = format(" head, ok = %s(head%s) done = done or ok -- %s %i",localized,args,group,i)
end
end
end
local processor = format(template,concat(vars,"\n"),args,concat(calls,"\n"))
-- print(processor)
return processor
end
--~ hans = {}
--~ taco = {}
--~ function hans.a(head,tail) print("a",head,tail) return head,tail,true end
--~ function hans.b(head,tail) print("b",head,tail) return head,tail,true end
--~ function hans.c(head,tail) print("c",head,tail) return head,tail,true end
--~ function hans.x(head,tail) print("x",head,tail) return head,tail,true end
--~ function taco.i(head,tail) print("i",head,tail) return head,tail,true end
--~ function taco.j(head,tail) print("j",head,tail) return head,tail,true end
--~ t = sequencer.reset()
--~ sequencer.appendgroup(t,"hans")
--~ sequencer.appendgroup(t,"taco")
--~ sequencer.prependaction(t,"hans","hans.a")
--~ sequencer.appendaction (t,"hans","hans.b")
--~ sequencer.appendaction (t,"hans","hans.x")
--~ sequencer.prependaction(t,"hans","hans.c","hans.b")
--~ sequencer.prependaction(t,"taco","taco.i")
--~ sequencer.prependaction(t,"taco","taco.j")
--~ sequencer.removeaction(t,"hans","hans.x")
--~ sequencer.setkind(t,"hans.b")
--~ sequencer.setkind(t,"taco.j","nohead")
--~ print(sequencer.tostring(t))
--~ s = sequencer.compile(t,sequencer.nodeprocessor)
--~ print(sequencer.nodeprocessor(t))
--~ print(s("head","tail"))