How to specify the number of characters in a regular expression in lua?

Question

Regular Expressions

local string = "qw.erty"
return string:match("([a-z]{2})%.")

Returns nil
There is not a word about this in the manuals.

Answer 1

For starters, it's best not to use a word stringfor the variable name, as it's a whole library for working with strings. You block access to it.
Lua does not have full-fledged regular expressions, because Lua was conceived as the lightest possible language. Instead, the so-called. "pattern match". So that {2}doesn't work. It's just that in most cases modifiers are enough. + - * ?
In your case, it will do:

local str = "qw.erty"
return str:match("([a-z][a-z])%.")

Or even:

local str = "qw.erty"
return str:match("(%l%l)%.")