in reply to Re: Understanding the benefit of Given/When ...
in thread Understanding the benefit of Given/When ...

> I have no idea what you are asking.

Maybe I'm not smart enough for Smart Match ;)

It seems that the operands in Smart Match are swapped to what I expected after reading the docs

Is perlsyn#Switch statements clear??? 

 Most of the power comes from implicit smart matching:
 
    when($foo)
 
is exactly equivalent to
 
    when($_ ~~ $foo)

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($_ was given)

and 

#  $a $b Type of Match Implied Matching Code
# ====== ===== ===================== =============
...
#  Array Regex array grep grep /$b/, @$a

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see perlsyn#Smart matching in detail

so when writing

 given (@a) {
    when (/abc/) {}
}

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I expect this to be tested:  @a ~~ /$b/ in the meaning of  grep /$b/, @$a

Two possibilities:

a) the docs need a rewrite!

b) my brain needs a rewrite! ;)

Cheers Rolf ...still confused...

UPDATE: Sorry personally I think that ~~ is far too overloaden with functionality to be easily understood!!!

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Re: Smart enough for Smart Match??? (was "Understanding ...Given/When" )
by ikegami (Patriarch) on Mar 04, 2010 at 17:45 UTC
    I don't know why the following doesn't work: 
    use 5.010;
use strict;
use warnings;

my @a='abc';
given (@a) {
    when (/abc/  ) { print "abc\n" }
    when (1      ) { print "#\n"   }
    when (['abc']) { print "copy\n" }
    when (\@a    ) { print "self\n" }
}

# copy

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    Why is it skipping Array Regex to go to Array Array?
[reply]
[d/l]
      Have a look at the last code in the OP (I updated it 10 minutes after posting)

      given(@array) and given(\@array) both produce the same ref in $_, but the smartmatch doesn't work as documented.

      While I can understand why to limit given to simple scalars I think the docs should either be updated to reflect this behaviour or it's a bug.

      UPDATE: you should add continues to se which clauses are true

      my @a=('abc',1);
given (@a) {
    when (/abc/  ) { print "abc\n" ;continue}
    when (1      ) { print "#\n"   ;continue}
    when (['abc',1]) { print "copy\n" ;continue}
    when (\@a    ) { print "self\n" }
}

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      OUTPUT 

      Argument "abc" isn't numeric in smart match at /home/lanx/tmp/ike_give
+n.pl line 9.
#
copy
self

      [download]

      Cheers Rolf

[reply]
[d/l]
[select]

        given(@array) and given(\@array) both produce the same ref in $_

        That's fine. ARRAY means array or array ref.

        I didn't get a chance to read the thread JavaFan started, but I gotta go for a bit now.

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