From: Robert Klemme <bob.news@...>
Date: 2004-01-28T18:29:54+09:00
Subject: Re: newbee question about "missing" hash methods +, += and <<


"benny" <linux@marcrenearns.de> schrieb im Newsbeitrag
news:20040127192241.26396079@bava.ho...
> >
> > No.  Arguments are:
> >
> > "+" is inefficient. (same for "-")
>
> dito with
> "string" += "other_string"

Yes.

> > "<<" has usually the semantics that the left side is a collection
while
> > the right side is an element.  And since each entry in a Hash needs a
key
> > value pair this could not be done with <<, because "<<" can only have
a
> > single argument.
>
> what about
>
> "a" << "bcd"

True.  String is special with respect to <<.

> > What should it do if the Hash contains Hashes as keys?  This is highly
> > ambiguous and not intuitive.
>
> no, its quite clear: it happens the same thing like
>
> myhash[{"key" => "val"}] = "other_val"

No, we were talking about "-":  If h is a Hash that contains hashes as
keys like h = { {"foo"=>"bar"} =>1 } then how is "h - x" interpreted if x
is a Hash?  It's ambiguous.

Regards

    robert