Well, my comment might have been a bit tongue-in-cheek 
but obviously you’d use parentheses to remove ambiguities .
[(blah 1 2) 3 4]
In elixir you have this problem today don’t you, because optional parenthesis?
foo bar 1, 2, 3
cmkarlsson
0
mythicalprogrammer
No in elixir. Yes in javascript.
I like it when elixir yell at me when I run mix. I do not like it when javascript yell at me, I also like to tell myself I know javascript long enough to handle whatever happen by adding trailing comma if something were to occur.
0
peerreynders
Why do you think people don’t mind extra commas but want parenthesis to be optional?
Easy from the Clojure perspective: (foo bar 1) is equivalent to Elixir’s foo(bar, 1). (foo (bar (1))) would be foo(bar([1])).
In Clojure, , is treated as whitespace, exactly the same as spaces, tabs, or newlines.
2
sribe
I always use parens in function calls. In my opinion, eliding parens should ONLY be used for macro invocations that extend syntax in such a way that parens would be awkward.
5
cmkarlsson
Beats me We are irrational human beings.
Probably because syntax is hard. And the more syntax you add, the more compromises and unintended side-effects you get as well.
From my point of view I find the syntax without parenthesis but with commas hard to mentally parse.
# In order of preference I think
# ML style looks good to me
let foo a b c = (a + b) * c
...
foo 1 2 3
# Lisp style looks good
(defun foo (a b c) (* c (+ a b)))
...
(foo 1 2 3)
# Elixr with parens
def foo(a, b, c) do
(a + b) * c;
end
foo(a, b, c)
# But elixir style without parens?
def foo a, b, c do
(a + b) * c
end
...
foo a, b , c
# with the optional brackets I have an even harder time
foo a, b, a: 1, b: 2, c: 3
To get back to the topic. Do I prefer trailing comma? I understand it makes refactoring and moving things around slightly easier but code looks more pleasant without it.
1
aenglisc
code looks more pleasant without it
That’s highly subjective. I am of the opposite opinion personally.
4
cmkarlsson
Yes of course. I never meant my reply to be authoritative. Perhaps I should have phrased it: “In my opinion the code look more pleasant without it.”
1
domvas
I don’t add trailing because back in the days I spent lots of hours tracking a bug which was only due one of these (PHP or JS I don’t remember which of these jewels).
Now I don’t ask myself if I wan’t them or not, I have formatters (or at least syle guide) for all languages!
0
joeerl
Creator of Erlang - Fondly Remembered
Umm - should you terminate English sentences with a comma instead of a period, in case you want to reorder the sub-clauses,
No, I don’t like this,
3
LostKobrakai
I find no trailing comma to be better readable. About the reordering / diffing argument I kinda feel like that could also be solved by more intelligent editors/diffing algorithms and mustn’t be done by me adding more commas.
3