Colon or Period?

[KawaGeo]

In the functions.txt file, many have colon and others, period. For example,

Code: Select all

Image Image.load( filename )
nil Image:save( filename )

I am somewhat confused between them. Can anyone explain the difference?

It is hard to remember which to use colon or period without understanding why.

Thanks.

[Shine]

Dots are used for kind of static functions, without an object, and colons are used, when calling a function on an object. E.g. i=Image.load("test.png") creates an object and i:save("image.tga") saves it and is a short form for Image.save(i, "image.tga").

[KawaGeo]

Reply in a nutshell, indeed. :)

Thanks.

[Shine]

You can find the glory details in the Lua manual ( http://www.lua.org/manual/5.0/ ) and your dot and colon question at http://lua-users.org/wiki/SimpleLuaClasses . Lua Player uses something like the simple class model for Image, Music etc. internally, so it is not a pure Lua question, which is the reason why I didn't locked this thread :-)