On Mon Mar 16 13:13:35 2015, elizabeth wrote:
> > On 16 Mar 2015, at 18:50, Christian Bartolomaeus via RT <bugs-
> > comm...@bugs6.perl.org> wrote:
> > $ perl6 -e 'say "abcd".index("xyz") == 0'
> > Invocant requires an instance, but a type object was passed
> > in method Bridge at src/gen/m-CORE.setting:5603
> > in sub infix:<==> at src/gen/m-CORE.setting:5521
> > in block <unit> at -e:1
>
> .index is speculated to return a StrPos object:
>
> "The value returned is always a C<StrPos> object. If the substring
> is found, then the C<StrPos> represents the position of the first
> character of the substring. If the substring is not found, a bare
> C<StrPos> containing no position is returned. This prototype
> C<StrPos>
> evaluates to false because it's really a kind of undefined value. Do
> not evaluate
> as a number, because instead of returning -1 it will return 0 and
> issue
> a warning.”
>
> This would imply it should not fail, but return True *and* give a
> warning!
>
>
> > $ perl6 -e 'say +Failure'
> > Invocant requires an instance, but a type object was passed
> > in method Numeric at src/gen/m-CORE.setting:15733
> > in block <unit> at -e:1
> > $ perl6 -e 'Failure == 0'
> > Invocant requires an instance, but a type object was passed
> > in method Numeric at src/gen/m-CORE.setting:15733
> > in sub infix:<==> at src/gen/m-CORE.setting:5323
> > in block <unit> at -e:1
>
> My feeling is that these should fail. Failure’s are supposed not be
> thrown only when being checked for definedness. Making it a number,
> does not meet that criterion in my opinion.
>
>
>
>
> Liz
StrPos is gone from the design docs, so this needs to be revisited.
--
Will "Coke" Coleda
