The well-cited RIP Hash rocket post would seem to imply the Hash Rocket syntax (:foo => "bar"
) is deprecated in favor of the new-to-Ruby JSON-style hash (foo: "bar"
), but I can't find any definitive reference stating the Hash Rocket form is actually deprecated/unadvised as of Ruby 1.9.
Fat comma (also termed hash rocket in Ruby and a fat arrow in JavaScript) refers to a syntactic construction that appears in a position in a function call (or definition) where a comma would usually appear.
In Ruby you can create a Hash by assigning a key to a value with => , separate these key/value pairs with commas, and enclose the whole thing with curly braces.
The author of that blog post is being overly dramatic and foolish, the =>
is still quite necessary. In particular:
You must use the rocket for symbols that are not valid labels: :$set => x
is valid but $set: x
is not. In Ruby 2.2+ you can get around this problem with quotes: '$set': x
will do The Right Thing.
You must use the rocket if you use keys in your Hashes that aren't symbols, such as strings, integers or constants. For example, 's' => x
is valid but 's': x
is something completely different.
You can kludge around the above in the obvious manner of course:
h = { } h[:'where.is'] = 'pancakes house?' # etc.
but that's just ugly and unnecessary.
The rocket isn't going anywhere without crippling Ruby's Hashes.
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With