Re: omit parenthesis for functions of zero arguments / custom control structures

[Gavin Kistner <gavin@...>]

On Feb 28, 2006, at 12:58 AM, Lisa Parratt wrote:
> I'm personally of the opinion that if a piece of syntax appears in  
> Perl, that's an excellent indication it should be avoided like the  
> plague.

That may (or may not) be a reasonably effective general filter, but I  
think that's a poor hard rule to apply. Gems can be found in the  
sewagiest places.


> Why does everyone always suggest features from that aborted  
> abomination of a language, rather than ones from SPARK, Z, or other  
> languages with a bit of class and back bone?

I this case, the concept of easy-to-type anonymous lambda functions  
comes from more than just Perl. Lisp and Ruby come to mind. The  
syntax in Ruby is remarkably similar:

	myHash.each{ |key,value| print( key, value ) }
or (also in Ruby)
	myHash.each do |key,value| print( key, value ) end

In cases where there are no arguments passed to the function, the  
parameter list can be omitted. Again, in Ruby:

	10.times do
		print( "Hello World" )
	end


In case it's not clear, the above are equivalent to the Lua code:

	table.foreach( myHash, function( key, value ) print( key, value ) end )

and (sort of)

	function times( n, f )
		for i=1,n do
			f( i )
		end
	end
	times( 10, function( )
		print( "Hello World" )
	end )


In my opinion, this is not a case of "I want Lua to be like Perl",  
but rather "Simple syntax sugar can make the difference between using  
the power of lambda functions, or deciding that it is too much work  
to type them. And, hey!, look, Perl has nice syntax for this!"