[redis.git] / deps / lua / test / trace-globals.lua

-- trace assigments to global variables

do
 -- a tostring that quotes strings. note the use of the original tostring.
 local _tostring=tostring
 local tostring=function(a)
  if type(a)=="string" then
   return string.format("%q",a)
  else
   return _tostring(a)
  end
 end

 local log=function (name,old,new)
  local t=debug.getinfo(3,"Sl")
  local line=t.currentline
  io.write(t.short_src)
  if line>=0 then io.write(":",line) end
  io.write(": ",name," is now ",tostring(new)," (was ",tostring(old),")","\n")
 end

 local g={}
 local set=function (t,name,value)
  log(name,g[name],value)
  g[name]=value
 end
 setmetatable(getfenv(),{__index=g,__newindex=set})
end

-- an example

a=1
b=2
a=10
b=20
b=nil
b=200
print(a,b,c)
Commit	Line	Data
21d3294c	1	-- trace assigments to global variables
	2
	3	do
	4	-- a tostring that quotes strings. note the use of the original tostring.
	5	local _tostring=tostring
	6	local tostring=function(a)
	7	if type(a)=="string" then
	8	return string.format("%q",a)
	9	else
	10	return _tostring(a)
	11	end
	12	end
	13
	14	local log=function (name,old,new)
	15	local t=debug.getinfo(3,"Sl")
	16	local line=t.currentline
	17	io.write(t.short_src)
	18	if line>=0 then io.write(":",line) end
	19	io.write(": ",name," is now ",tostring(new)," (was ",tostring(old),")","\n")
	20	end
	21
	22	local g={}
	23	local set=function (t,name,value)
	24	log(name,g[name],value)
	25	g[name]=value
	26	end
	27	setmetatable(getfenv(),{__index=g,__newindex=set})
	28	end
	29
	30	-- an example
	31
	32	a=1
	33	b=2
	34	a=10
	35	b=20
	36	b=nil
	37	b=200
	38	print(a,b,c)