Does lua internally parse all number into string?

[zaker <zgmfzaku@...>]

I use "lua_rawseti(L, -1, 0)" to set a table's 0 index.  

And I write a function that will get the entry from table. The function prototype is "GetValue( index, table )".

I just can't get the value by "GetValue( 0, table )" or "GetValue( '0', table )".

But it's ok when use terminal

Lua 5.1.5  Copyright (C) 1994-2012 Lua.org, PUC-Rio

> t = {}

> t[0] = 1

> print(t[0])

1

> print(t['0'])

nil

> 

Is there any rules how lua parse number ?