Re: Lua interpreter and Lua files encoding

[Dirk Laurie <dpl@...>]

On Thu, Jan 06, 2011 at 12:45:43PM +0200, Peter Odding wrote:
> > Anyway, is this only an implementation artifact? Or is something that
> > will last? In this latter case a mention in the reference manual could
> > be useful, since utf8 is very common nowadays and generating utf8 files
> > using Lua, _without specialized libraries_ and without the hassle of
> > encoding literals with escape sequence, is really a useful!
> 
> The Lua 5.1 reference manual defines that "strings in Lua can contain 
> any 8-bit value" but it doesn't guarantee the same for literal strings 
> embedded in Lua source code. 

Theorem: Given any literal string, it is possible to embed it into
    Lua source code.

Proof: Suppose the string is N bytes long.  Then it cannot contain
    the substring '['..string.rep('-',N-1)..']'.  That string
    delimiter is therefore adequate for embedding the string. Q.E.D.

Dirk