mutable default parameter problem [Prothon]

Michele Simionato michele.simionato at
Thu Jun 17 05:33:28 CEST 2004

"Mark Hahn" <mark at> wrote in message news:<5L2Ac.26$u%3.13 at fed1read04>...
> FYI: It's not that the exclamation mark causes append to return the
> sequence.  The exclamation mark is always there and the sequence is always
> returned.  The exclamation mark is the universal symbol for in-place
> modification.  This is straight from Ruby and solves the problem that caused
> Guido to not allow sequences to be returned.  And, yes, I do think that's
> worth bragging about ;-)

I think the esclamation mark comes from Scheme if not from a more
ancient language. It is certainly not a new idea. OTOH, it is a good
idea, no question
about that. Same for "?" in booleans.

       Michele Simionato

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