Is Hash Rocket deprecated?

问题

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.

回答1:

The author of that blog post is being overly dramatic and foolish, the => is still quite necessary. In particular:

1. You must use the rocket for symbols that require quoting: :'where.is' => x is valid but 'where.is': x is not. Ruby 2.2 has fixed this problem so you can say 'where.is': x in Ruby 2.2+.
2. 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.
3. You must use the rocket if you use keys in your Hashes that aren't symbols: '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.

来源：https://stackoverflow.com/questions/10004158/is-hash-rocket-deprecated