In Lua, to view the members of a object, you can use: for key,value in pairs(o) do print(“found member ” .. key); end Unfortunately I don’t know if this will work for objects imported from C++.
Lua doesn’t have strict arrays like other languages – it only has hash tables. Tables in Lua are considered array-like when their indices are numerical and densely packed, leaving no gaps. The indices in the following table would be 1, 2, 3, 4. local t = {‘a’, ‘b’, ‘c’, ‘d’} When you have an array-like … Read more
In response to some of the other answers and comments: It is true that as a programmer you should generally avoid premature optimization. But. This is not so true for scripting languages where the compiler does not optimize much — or at all. So, whenever you write something in Lua, and that is executed very … Read more
Try Valgrind (it’s free, open-source): The Valgrind distribution currently includes six production-quality tools: a memory error detector, two thread error detectors, a cache and branch-prediction profiler, a call-graph generating cache profiler, and a heap profiler. It also includes two experimental tools: a heap/stack/global array overrun detector, and a SimPoint basic block vector generator. It runs … Read more
This is all very simple. First, you load the Lua script without executing it. It does not matter if you have connected the Lua state with your exported functions; all you’re doing is compiling the script file. You could use luaL_loadfile, which uses C-standard library functions to read a file from disk and load it … Read more
Lua is a cool language, light-weight and extremely fast! But the point is: Is performance so important for those tasks you mentioned? Renaming a bunch of files Download some files from the web Webscraping You write those programs once, and run them once, too maybe. Why do you care about performance so much for a … Read more
Try this str=”cat,dog” for word in string.gmatch(str, ‘([^,]+)’) do print(word) end ‘[^,]’ means “everything but the comma, the + sign means “one or more characters”. The parenthesis create a capture (not really needed in this case).
You’re missing the arg vector, which has the elements you want in arg[1], arg[2], and so on: % lua -i — /dev/null one two three Lua 5.1.3 Copyright (C) 1994-2008 Lua.org, PUC-Rio > print(arg[2]) two > More info in the Lua manual section on Lua standalone (thanks Miles!).
There is no build-in math.round() function in Lua, but you can do the following: print(math.floor(a+0.5)).
Awesome WM: Move window from one screen to another [closed]