Re: Language Syntax

["Thiago L." <fakedme@...>]

On 21/06/2014 19:33, David Given wrote:
> On 21/06/14 20:34, Duncan Cross wrote:
> [...]
> > My understanding is that the blurred distinction between statement and
> > expression that you find in C adds a level of complexity to the parser
> > that (the Lua team have decided) is not justified. As a language that
> > is usually parsed at run-time, Lua's syntax is designed, from the
> > bottom up, to be parsed/compiled quickly. A strict separation between
> > statement and expression is a part of this.
> I've tried to implement this sort of thing myself. It's a pig, with
> rough edges everywhere. Consider:
>
> a, b, c = function_returning_multiple()
>
> vs.
>
> function_with_arguments(a, b, c = function_returning_multiple())
If only...
func(a,b,c = ..., something) -- calls func with (...[1], ...[2], ...[3], 
something)
func(..., select(2,...), select(3,...), something) -- the slow way Lua 
currently supports
func((function(a,b,c,d) return b,c,d,a end)(something, ...)) -- another 
way to do it, faster in 5.2 but still slower than handcrafted bytecode

(Altho I am thinking about something different, and either way it's 
ambiguous...)
> Making assignments expressions simplifies things no end.