| -- 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) |
