Re; conditional replace

[Duck <duck@...>]

> I need to iterate four times because the subs need to be
> applied in a certain order:
[snip]
> "Note, there is no guarantee as to the  order in which keys
> will be stored in a table when using dictionaries so 
> the order of retrieval of keys using pairs() is not guaranteed."

You can make what amounts to an "ordered dictionary" by making your 
substitution table both an array and a dictionary, something like this:

 subs = {
   1 = ">~h|",
   2 = "<~h|",
   3 = ">~w|",
    ...
   23 = "<p",

   ">~h|" = GREEK_SMALL_LETTER_ETA_WITH_PSILI_AND_[...snip...]
    ...
   "<p"   = GREEK_SMALL_LETTER_RHO_WITH_DASIA
 }

Then you can write something like this:

 local function mysubs(lines)
    for _,v in ipairs(subs) do
      lines = string.gsub(lines,v,subs[v]);
    end;
    return lines;
 end;

This works because ipairs() does bring out the "array-style" entries (i.e. 
those with index 1..n) in a table in numeric order.