In the [Github Ruby Styleguide][1] there's a note about Hashes:
`Use hashrocket syntax for Hash literals instead of the JSON style
introduced in 1.9.`
I guess the reason is that if you use hashrocket syntax, you can use
any type as a hash key, while with colon the keys are `Symbol` only.
So, you'll (pretty much) always have two styles in your app.
Strict styleguides are important. What if we all start to do crazy
things like `@VARIABLE` or `CamelCaseConstant = [1, 2, 3]`? (and I've
seen such cases, unfortunately).
But in this particular case with hashes, I personally use mixed style.
So, colon for simple key-value hashes, where value is not a `Symbol`
itself. And hashrocket for mixed DSL hashes with "complex" values.