Re: [pure-lang-users] Proposed syntax changes

[Eddie R. <er...@bm...>]

On Thu, 2008-08-14 at 22:59 +0200, Albert Graef wrote:

> it's worth the effort, because it sucks having to write 
> (1,2):(3,4):...:[] all the time.

+1

> - I'd also like to revise the syntax of 'using' so that the module names 
> are separated by commas, which is more in line with the 'extern' 
> declaration syntax which also uses the comma delimiter. (I'd still like 
> to keep the syntax of operator and 'nullary' declarations, though, 
> because there whitespace as a delimiter is much easier to read when 
> listing non-alphanumeric symbols, IMHO.)

OK by me.

> - The discussion I had with Libor about how to implement a sequencing 
> operator ("first x, then y") also kept me thinking, because the solution 
> I proposed there is not tail-recursive. To do this in a proper way, we'd 
> need a built-in sequencing operator (special form). While it's not 
> strictly needed, it's much more convenient than having to write 'y when 
> _ = x end' all the time.
> That sequencing operator should be easy to implement, but how should it 
> be named? We can't use Q's '||' because that's logical or in Pure, and 
> we can't use C's ',' because that's Pure's tupling operator. Another 
> obvious choice would be the Haskell'ish monadic sequencing operator '>>' 
> but that's currently used for bit shifts (maybe I could rename '<<'/'>>' 
> to shl/shr, though). Any other ideas?

I've been using $$ or |> but whatever you decide is fine by me.
One minor quibble. Could we use ++ for list and string concatenation? It
interferes with using + for adding matrices when they are implemented as
lists of lists. 

> Finally (this is not a syntax change, but it also breaks backward 
> compatibility), I'd like to revise the script search. Currently the 
> interpreter always searches the current directory and then the PURELIB 
> directory. In the case that the interpreter is run with a main script 
> (pure -x main.pure), I think it makes sense to search the directory of 
> the main script instead of the cwd (for scripts loaded with a 'using' 
> clause). That would make it possible to install the main script along 
> with any other non-library modules it needs into its own directory and 
> run it from there. This would be useful, in particular, for "shebang" 
> scripts.

+1

Does TIA mean "The Intellectual Activist?" ;-)

e.r.