Oct  4 08:44 2013 complexUtilities.lua Page 1


--[[ Complex Number Utility Module
     H. Conrad Cunningham, Professor
     Computer and Information Science
     University of Mississippi

Developed for CSci 658, Software Language Engineering, Fall 2013

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2013-09-22: Separated utilities module from representation modules


--]]


-- Function "square" takes an argument "x" and returns its square.

local function square(x) return x * x  end


-- Function "show_data" converts raw Lua data structures to strings to
-- assist in debugging and testing.  This was not in the SICP Scheme
-- package.

local function show_data(d)
  if type(d) == "table" then
    local res = {}
    for k,v in pairs(d) do
      res[#res+1] = "[" .. show_data(k) .. "] = " .. show_data(v)
    end
    return "(" .. table.concat(res, ", ") .. ")"
  else
    return tostring(d)
  end
end


-- MODULE EXPORT LIST

return { square     = square,
         show_data  = show_data
       }