implicit array suggestion

[dbrans]

Commas are reserved for function arguments and array elements. However, if there's no function, is there any harm in interpreting an expression like "3, 4, 5" as an array? Would it be useful?

examples off the top of my head:

x = 3, f(2, 3), 5

x: 3, 4, 5

(3, 4, 5).slice 0

x for x in 3, 4, 5

And there's no reason it shouldn't work like function arguments, where only the first comma is mandatory:
x,
f 3
z

Thoughts?

[michaelficarra]

There are some glaring ambiguities here. Do you mind writing up a grammar or something to better illustrate your suggestion?

[jrus]

What's the benefit? Just saving two characters? (and not even in the (3, 4, 5).slice 0 case, since you can already write [3, 4, 5].slice 0 or even [3..5].slice 0.)

OTOH, cleaner dereferencing assignment would be a slightly bigger advantage. You could do e.g.: a, b, c = b, c, a

[jashkenas]

Too many ambiguities for this one, I'm afraid.

a = 1, 2, 3 # array
a 1, 2, 3 # 3 args
a(1, 2, 3) # 3 args
a (1, 2, 3) # array?

[dbrans]

a (1, 2, 3) # definitely 1 arg: array.
Just as
a (o = {}; o.b = 3; o) # is 1 arg
and
a(o = {}; o.b = 3; o) # is 3 arg