local METAPHONE_LENGTH = 4   -- how many characters of metaphone to get back
local EDIT_DISTANCE = 4      -- how close a word must be to appear in the list of suggestions
local CASE_SENSITIVE = false -- compare case? true or false

local make_upper  -- this becomes the upper-case conversion function, see below

-- sort function for sorting the suggestions into edit-distance order
local function suggestions_compare (word)
   return function (a, b)
     local diff = utils.edit_distance (make_upper (a), word) - 
                  utils.edit_distance (make_upper (b), word) 
     if diff == 0 then
       return make_upper (a) < make_upper (b)
     else
       return diff < 0
     end -- differences the same?
  end -- compareit
end -- function suggestions_compare

function GetSpellCheckCorrections (word)

  -- make a suitable function depending on whether they want case-sensitive or not
  if CASE_SENSITIVE then
    make_upper = function (s) return s end -- return original
  else
    make_upper = function (s) return s:upper () end  -- make upper case
  end -- case-sensitivity test

  uc_word = make_upper (word)  -- convert to upper-case if wanted

  -- path to the spell check dictionaries
  local directory = utils.info ().app_directory .. "spell\\"

  -- open database on disk
  db = assert (sqlite3.open( directory .. "spell.sqlite"))


  -- table of suggestions, based on the metaphone
  local keyed_suggestions = {}
  
  -- get both metaphones
  local m1, m2 = utils.metaphone (word, METAPHONE_LENGTH)
  
  local function lookup_metaphone (m)
    local found = false
    for row in db:rows(string.format ("SELECT name FROM words WHERE metaphone = '%s'", m)) do
      local word = row [1]
      if make_upper (word) == uc_word then
        found = true -- found exact match
        break
      end  -- found
      if utils.edit_distance (make_upper (word), uc_word) < EDIT_DISTANCE then
        keyed_suggestions [word] = true
      end -- close enough
    end
    return found
  end -- lookup_metaphone
  
  -- look up first metaphone
  if lookup_metaphone (m1) then
    db:close ()
    return word, "ok"
  end -- word found

  -- try 2nd metaphone
  if m2 then
    if lookup_metaphone (m2) then
      db:close ()
      return word, "ok"
    end -- word found
  end -- have alternate metaphone

  -- pull into indexed table
  local suggestions = {}
  for k in pairs (keyed_suggestions) do
    table.insert (suggestions, k)
  end -- for 
     
  table.sort (suggestions, suggestions_compare (uc_word))

  db:close ()
  return suggestions

end -- GetSpellCheckCorrections

t = GetSpellCheckCorrections ("indstry")
tprint (t)

1="industry"
2="industry's"
3="windsurf"

GetSpellCheckCorrections(word)

tprint(GetSpellCheckCorrections("indstry"))

{ 1="industry", 2="industry's", 3="windsurf" } -- Note: most likely corrections at beginning!