[parenscript-devel] Vector literals

I pushed a small patch so PS can handle vector literals. These obviously map to the same thing as lists (namely, JS arrays).

(ps #(1 2 3)) => "[1, 2, 3];"

(ps #(1 2 #(a b) 3)) => "[1, 2, ['a', 'b'], 3];"

It's helpful to have this notation for anyone who's trying to maintain common code across CL and Parenscript (as we are). In principle, I feel that extensions to PS that exist purely to support this goal should probably not be in the core library. But the above change requires hacking the compiler, so I went ahead and put it in. If there are objections, we can remove it.

Daniel