[Nickle]Removing type names from literal structured values (was: Re: crashing nickle in <100 bytes)

[Carl Worth]

On Jul 23, Keith Packard wrote:
 > > One thing that I would like is if I could assign a structured value
 > > without explicitly providing its type, (in the same style as the
 > > initializer)
 > 
 > Yes, that would be nifty, but it requires transmitting type information 
 > backwards across the assignment operator.  As these values can occur in 
 > any expression context, the general solution requires fairly complete type 
 > inference which is about to be thrown out the window in favor of algebraic 
 > types.

I don't actually want the complete type interference. Here's where I'm
at as a programmer:

1) I like to provide types for variables, function arguments, and
   function returns.

2) I don't like having to provide the types for literal structured
   values when they are used in any of the above contexts.

3) I don't mind having to provide the type if a literal structured
   value is used in other contexts within an expression.

So, my proposal would only reflect type information backwards across
assignment, passing arguments to functions, and return
statements. Would that be reasonable?

If nickle supported this, then anonymous arrays could provide a more
flexible approach to variable length argument lists with minimal extra
typing on the part of the programmer:

	int foo(int[*] args) {
		...
	}

	int bar(int[*] args, int[*] other_args) {
		foo(args);
		...
	}

	bar({1, 2, 3}, {4, 5, 6});

That would be most pleasant. What do you think?

I might not go as far as getting rid of the current variable-length
argument list functionality in favor of anonymous arrays. I don't
know if I could ever get used to typing extra braces in printf. ;-)

So, even with this, I'd probably still want the new "args ..." syntax
for passing an array to a function accepting "args ...".

-Carl

-- 
Carl Worth                                        
USC Information Sciences Institute                 cworth@east.isi.edu
3811 N. Fairfax Dr. #200, Arlington VA 22203		  703-812-3725