pretty.lua

pretty.lua

local function tostring_pretty(value, cache, ident)
  if type(value) ~= "table" then
    if type(value) == "string" then
      return '"' .. tostring(value) .. '"'
    end
    return tostring(value)
  end
  cache = cache or {}
  ident = ident or "  "

  if cache[value] then
    return cache[value]
  end

  local ks = {}
  for k, _ in pairs(value) do
    table.insert(ks, k)
  end
  table.sort(ks, function(a, b)
    return tostring(a) < tostring(b)
  end)

  local ps = { "{" }
  if #ks > 0 then
    table.insert(ps, "\n")
  else
    ident = ""
  end
  for i = 1, #ks do
    local k = ks[i]
    local v = value[k]
    local vs = tostring_pretty(v, cache, ident .. "  ")
    if type(k) == "number" then
      if i == 1 then
        table.insert(ps, ident)
      end
      table.insert(ps, vs .. ", ")
      if type(ks[i + 1]) ~= "number" then
        table.insert(ps, "\n")
      end
    else
      cache[value] = vs
      table.insert(ps, ident .. k .. " = " .. vs .. ",\n")
    end
  end

  ident = ident:sub(1, #ident - 2)
  table.insert(ps, ident .. "}")
  return table.concat(ps, "")
end

return tostring_pretty