Lua 5.2: Can you explain this behaviour?

[Eric Man <lericl.mailbox@...>]

I downloaded a macosx binary of Lua 5.2 from the main website last week.

If you run the code snippet, it'll print "= a<a<". I'd have thought it would be "= a<<.>a<<.>>".

If you toggle line 4 off, though, it will print "= a<<.>a<<.>>" as expected.

I don't understand why, can anyone explain? See the following two code samples.

local function test(bool)

  local w, t

  if bool 

 --or true  --- toggle this line

then 

    t = "a"

    w = function (s) t = t .. tostring(s) end

    _ENV.w = w

  else

    t = "."

  end

  

  local function r() 

    if bool then

     print("r", test(false))

    end

    return t

  end

  _ENV.r = r

  loadstring("w('<') w(r()) w('>')")()

  return t

end

print("=", test(true))

prints:

r .

= a<<.>a<<.>>

local function test(bool)

  local w, t

  if bool 

 or true  --- toggle this line

then 

    t = "a"

    w = function (s) t = t .. tostring(s) end

    _ENV.w = w

  else

    t = "."

  end

  

  local function r() 

    if bool then

     print("r", test(false))

    end

    return t

  end

  _ENV.r = r

  loadstring("w('<') w(r()) w('>')")()

  return t

end

print("=", test(true))

prints:

r a<a<>

= a<a<