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if not modules then modules = { } end modules ['typo-lan'] = {
version = 1.001,
comment = "companion to typo-lan.mkiv",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
local type, next = type, next
local currentfont = font.current
local setmetatableindex = table.setmetatableindex
local utfbyte = utf.byte
local hashes = fonts.hashes
local fontdata = hashes.characters
local emwidths = hashes.emwidths
local frequencies = languages.frequencies or { }
languages.frequencies = frequencies
local frequencydata = { }
local frequencyfile = string.formatters["lang-frq-%s.lua"]
local frequencycache = { }
setmetatableindex(frequencydata, function(t,language)
local fullname = resolvers.findfile(frequencyfile(language))
local v = fullname ~= "" and dofile(fullname)
if not v or not v.frequencies then
v = t.en
end
t[language] = v
return v
end)
setmetatableindex(frequencycache, function(t,language)
local dataset = frequencydata[language]
local frequencies = dataset.frequencies
if not frequencies then
return t.en
end
local v = { }
setmetatableindex(v, function(t,font)
local average = emwidths[font] / 2
if frequencies then
local characters = fontdata[font]
local sum, tot = 0, 0
for k, v in next, frequencies do
local character = characters[k] -- characters[type(k) == "number" and k or utfbyte(k)]
tot = tot + v
sum = sum + v * (character and character.width or average)
end
average = sum / tot -- widths
end
t[font] = average
return average
end)
t[language] = v
return v
end)
function frequencies.getdata(language)
return frequencydata[language]
end
function frequencies.averagecharwidth(language,font)
return frequencycache[language or "en"][font or currentfont()]
end
-- Just because we can, we also have a setter ...
local dimension_value = tokens.values.dimension
local scanstring = tokens.scanners.string
local scandimension = tokens.scanners.dimension
interfaces.implement {
name = "languagecharwidth",
public = true,
usage = "value",
actions = function(what)
local language = scanstring()
local font = currentfont()
if what == "value" then
return dimension_value, frequencycache[language][font] or 0
else
frequencycache[language][font] = scandimension(false,false,true)
end
end,
}
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