Lua is a case sensitive language.
Identifiers can be any string of letters, digits, and underscores,
not beginning with a digit.
The following words are reserved, and cannot be used as identifiers:
and do else elseif end
function if local nil not
or repeat return until then while
The following strings denote other tokens:
~= <= >= < > == = .. + - * /
% ( ) { } [ ] ; , .
Literal strings can be delimited by matching single or double quotes, and can contain the C-like escape sequences '\n' , '\t' and '\r' . Literal strings can also be delimited by matching [[ ... ]] . Literals in this last form may run for several lines, may contain nested [[ ... ]] , and do not interpret escape sequences.
Comments start anywhere outside a string with a double hyphen (-- ) and run until the end of the line.
Numerical constants may be written with an optional decimal part,
and an optional decimal exponent.
Examples of valid numerical constants are:
4 4.0 0.4 4.57e-3 0.3e12