Re: ~= vs. !=

["Peter S. Housel" <housel@...>]

"Nick Trout" <nick@rockstarvancouver.com>
> Dylan uses ~= as well. != seems to be the highest median use but ~= is
> not the only variant.

Actually, Dylan uses ~= as the complement of = (the redefinable/numeric
equality operator), and ~== as the complement of == (the object identity
equality operator).  I often get these confused, trying to write ~== in Lua,
as the Monday project (http://monday.sourceforge.net) contains both Dylan
and Lua code.

Something people have been ignoring in this discussion is that Lua is both a
language definition and a language implementation.  The argument should not
be made that it would be simple to make such-and-such a syntax change to the
Lua interpreter, without taking into consideration how it might affect the
formal language definition (including whether or not the grammar remains in
LL(1) and LALR(1)), or any difficulties it might cause for some other
implementation that had a more clearly separated lexer, screener, and
parser.

-Peter-