"with"...
with 'apple'.index('a') { say "Found at position $_" } else { "Not here" }
# Found at position 0
with 'apple'.index('b') { say "Found at position $_" } else { "Not here" }
# Not here
-y
On Tue, Sep 11, 2018 at 8:16 AM, Timo Paulssen <t...@wakelift.de> wrote:
> On 11/09/18 17:11, yary wrote:
>
> "Nil... it's a constant, so you have to use =:= to check for equality."
>
> Can you elaborate on that requirement? == works for an equality checks
> with numeric constants- must be more than Nil's constant-ness that makes
> one use =:= - perhaps that Nil doesn't numify to anything?
>
>
> Nil does numify, but using == comparison for this is still problematic for
> two reasons:
>
> 1) Nil numifies to 0, which is a valid "true" result for the index method
> and
> 2) it outputs a warning:
>
> Use of Nil in numeric context
> in block <unit> at -e line 1
>
> using ~~ instead of =:= should also be okay, or checking for definedness
> with either .defined or using "with" instead of "if", which is very useful
> especially for index and friends.
>
> HTH
> - Timo
>
