fuzzy.lua

#!/usr/bin/env texlua

--
-- usage: texlua fuzzy.lua KEYWORD
--

kpse.set_program_name(arg[-1])

function main()
  if not arg[1] then
    os.exit(1)
  end

  tlp_doclist = load_tlpdb_cache()

  min, result = 100, ''

  start = os.clock()

  -- fuzzy search:
  -- select a tlp whose Levenshtein distance to keyword is the smallest
  for p in pairs(tlp_doclist) do
    tmp = levenshtein(arg[1], p)
    if tmp < min then
      min, result = tmp, p
    end
  end

  stop = os.clock()

  if min < 100 then
    print('Result: ' .. result)
    print('Levenshtein distance: ' .. min)
  end

  print('Time: ' .. ((stop - start)*1) .. '[s]')
end

function load_tlpdb_cache()
  local TEXMFVAR = kpse.var_value('TEXMFVAR')
  local filename = TEXMFVAR .. '/texdoc/cache-tlpdb.lua'
  local s_meta, tlp_from_runfile, tlp_doclist = dofile(filename)
  return tlp_doclist
end

-- definition from <http://lua-users.org/lists/lua-l/2008-01/msg00095.html>
function levenshtein(s, t)
  local s, t = tostring(s), tostring(t)
  if type(s) == 'string' and type(t) == 'string' then
    local m, n, d = #s, #t, {}
    for i = 0, m do d[i] = { [0] = i } end
    for j = 1, n do d[0][j] = j end
    for i = 1, m do
      for j = 1, n do
        local cost = s:sub(i,i) == t:sub(j,j) and 0 or 1
        d[i][j] = math.min(d[i-1][j]+1, d[i][j-1]+1, d[i-1][j-1]+cost)
      end
    end
    return d[m][n]
  end
end

main()