[E-Lang] Syntax change: reducing side-effects

[Dean Tribble]

Thanks for all the comments!

>Summary: all defining occurrences of names now default to 'final', unless 
>they are prefixed by 'var', in which case they are settable.  In addition, 
>'var' can be used as a top-level construct as an alternative to 'define' 
>(equivalent to 'define var').

One minor nit left; does the following mean anything?

var [foo, bar] = [3, 4]

The alternatives are:

def var [foo, bar] = [3, 4]

which I presume the parser sneers at; or:

def [var foo, var bar] = [3, 4]

which I presume the rest of us sneer at; i.e., I prefer the compiler 
rejection because it seems that any principle that would make the 
dissociated 'var' semantically correct would also increase the perceived 
complexity and violate the basic rule of making assignable variables 
painfully clear.  (If you find that sentence hard to parse, remember that 
the next time you write deeply nested code...).