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if not modules then modules = { } end modules ['l-set'] = {
version = 1.001,
comment = "companion to luat-lib.tex",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
set = set or { }
local nums = { }
local tabs = { }
local concat = table.concat
set.create = table.tohash
function set.tonumber(t)
if next(t) then
local s = ""
-- we could save mem by sorting, but it slows down
for k, v in pairs(t) do
if v then
-- why bother about the leading space
s = s .. " " .. k
end
end
if not nums[s] then
tabs[#tabs+1] = t
nums[s] = #tabs
end
return nums[s]
else
return 0
end
end
function set.totable(n)
if n == 0 then
return { }
else
return tabs[n] or { }
end
end
function set.contains(n,s)
if type(n) == "table" then
return n[s]
elseif n == 0 then
return false
else
local t = tabs[n]
return t and t[s]
end
end
--~ local c = set.create{'aap','noot','mies'}
--~ local s = set.tonumber(c)
--~ local t = set.totable(s)
--~ print(t['aap'])
--~ local c = set.create{'zus','wim','jet'}
--~ local s = set.tonumber(c)
--~ local t = set.totable(s)
--~ print(t['aap'])
--~ print(t['jet'])
--~ print(set.contains(t,'jet'))
--~ print(set.contains(t,'aap'))
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