Where is it legal to use ruby splat operator?

Question

Splats are cool. They\'re not just for exploding arrays, although that is fun. They can also cast to Array and flatten arrays (See http://github.com/mischa/splat/tree/master

Answer 1

The "splat operator" is in fact not an operator at all but a token defined in the Ruby grammar. A read through grammar.y or the Ruby grammar in BNF form* will tell you that it is allowed as the last or only argument:

• in a method definition (except for an optional last &foo)
• in a method call (except for an optional last &foo)
• on the LHS of as assignment, for example: a, b, *cs = [1,2,3,4]
• on the RHS of an assignment, for example: a, b, c = 1, 2, *[3,4,5]
• in the when clause of a case statement