Object literals should use values from scope when using short syntax

[jcubic]

According to the documentation:

lips> (let ((foo 10) (bar 20)) &(:foo :bar))
&(:foo #<undefined> :bar #<undefined>)

this should reutnr &(:foo 10 :bar 20)

Another issue is that prism highlighting doesn't support shorthand syntax.

[jcubic]

this works now:

(let ((foo 10) (bar 20))
  (object :foo :bar))

But &(:foo :bar) doesn't work, maybe because syntax extensions run at parse time.

Need to investigate.

[jcubic]

That's right there is a bit of inconsistency here:

lips> (lips.parse "&(:foo 10)")
#(&(:foo 10))
lips> (lips.parse "`(foo bar)")
#((quasiquote (foo bar)))

The first expression should evaluate into:

#((object-literal :foo 10))

To solve this issue default syntax extensions should be just simple mappers:

(define (object-literal-map x)
  `(object-literal ,@x))

(set-special! "&" 'object-literal-map)

(let ((foo 10)) &(:foo))
;; ==> &(:foo 10)

Real macros can be left to reader macros tracked in #150

[jcubic]

This breaks tests and because of this object literals don't work anymore as vectors:

(let ((x 10)) `&(:foo ,x))
;; ==> (object-literal :foo 10)

(let ((x 10)) `#(1 2 ,x))
;; ==> #(1 2 10)

but now object literals works as a quotation:

`'(foo)
;; ==> (quote (foo))

I think that it will be better to update tests.

[jcubic]

Found old commented-out unit tests that define how this should work, so restored the old behavior:

lips> (let ((foo 10) (bar 20)) &(:foo :bar))
&(:foo #<undefined> :bar #<undefined>)

But also added read-only properties. The below code will throw an error:

(let ((x &(:foo :bar 10)))
  (set! x.bar 20))