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Returning Arrays?
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From:
John M. Dlugosz
Date:
April 16, 2008 01:49
Subject:
Returning Arrays?
How do you declare a function that returns an array? Something like
sub foo (blah) is Array of X { ... }
seems right, but it has two problems. First is a real problem, and is a
mistake seen a lot in C# and the .NET framework. A concrete type is
used when it should be an interface. What if the function wants to use
a List or Seq or some bizzare tied thing of its own? Defining it as
sub foo (blah) is Positional of X { ... }
is not as snappy, and I don't think it will catch on. (I'm still
wondering whether Lists and Seq's are Positional anyway, merely lazy
about it)
So that brings me to the second problem. For parameters, it's no
problem because people just use the @ sigil and don't think about
containers. So how do I do that with the return value? I don't name
the return value, so there is no place to put the sigil.
sub foo (blah) is X @*
perhaps? I seem to recall seeing sigils in a signature without names,
but now I can't remember where.
--John
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Returning Arrays?
by John M. Dlugosz