Re: Potential Tie::Memoize Bug

I can't explain the second issue, but the first is your bug. Returning undef explicitly to indicate falsehood is almost always an error. There are two circumstances where it's okay:

Where you've documented it explictly.
Where you use wantarray to do the right thing in list versus scalar context.

I don't think the second case is that useful; bare return does the right thing for you.

Comment on Re: Potential Tie::Memoize Bug

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Re^2: Potential Tie::Memoize Bug by satchm0h (Beadle) on Mar 17, 2005 at 01:22 UTC
`sub foo { return; } @ret = foo(); die "Not a Bug\n" unless @ret; print "Doh...shouldn't get here!\n"` [download] Results: `Not a Bug` [download] Excellent! Thanks chromatic ! I still find it curious that he calls the exists function in list context. I can't imagine I'm the only one who has been bitten by this. From the return perldoc for those too lazy to look it up themselves: `return EXPR .......snip....... If no EXPR is given, returns an empty list in list context, the undefined value in scalar context, and (of course) nothing at all in a void context.` [download]	[reply] [d/l] [select]

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Re^2: Potential Tie::Memoize Bug
by satchm0h (Beadle) on Mar 17, 2005 at 01:22 UTC

sub foo {
  return;
}

@ret = foo();
die "Not a Bug\n" unless @ret;
print "Doh...shouldn't get here!\n"
[download]

Not a Bug
[download]

chromatic

I still find it curious that he calls the exists function in list context. I can't imagine I'm the only one who has been bitten by this.

From the return perldoc for those too lazy to look it up themselves:

return EXPR
.......snip.......
If no EXPR is given, returns an empty list in list context,
the undefined value in scalar context, and (of course)
nothing at all in a void context.
[download]

[reply]
[d/l]
[select]