Comment by kragen

It depends on which alternative you're thinking of.

- }, like C: Lua uses this to terminate tables. You could use the same token for both purposes (Perl5 does) but the reduced redundancy comes at some cost to both readability and syntax error reporting, which are especially important in languages aimed at driveby programmers, like Lua.

- ): Lisps generally just use ) to terminate every construct, reducing redundancy further.

- different end tokens for each construct, like Ada and the Bourne shell (endif/end if/fi): improves readability and error reporting further, but requires more reserved words and is wordier.

- end, like Lua: intermediate among the above choices.

- indentation, like Python: seems to work well enough in Python, and especially helps beginners who are therefore not permitted to indent their code incorrectly, and adds a maximum amount of redundancy for opening and closing constructs (every line is explicitly tagged with its syntactic depth) without reducing readability. However, this aspect of Python was novel when Python was introduced, remains controversial, and has not been widely adopted in new languages.

A funny thing about Lua's syntax is that it's not newline-sensitive, but semicolons are optional. This is valid Lua:

    function x(a, b)f(a)f(b)g = a b = a end

Wherever two things are juxtaposed that can't be part of a single statement, it tries to parse them as two statements. This syntactic looseness means that some syntax errors that would be easily detected in semicolon languages aren't easily detected in Lua. This increases the penalty for removing additional syntactic redundancy.