2 – The Language
This section describes the lexis, the syntax, and the semantics of Lua. In other words, this section describes which tokens are valid, how they can be combined, and what their combinations mean.
The language constructs will be explained using the usual extended BNF, in which {a} means 0 or more a‘s, and [a] means an optional a. Non-terminals are shown in italics, keywords are shown in bold, and other terminal symbols are shown in typewriter
font, enclosed in single quotes.