Context and coercion

[Joshua Choi]

Kudos to all on the Perl 6 mailing list,

What's the conceptual difference (or relationship) between context and type
coercion? Is
$moose.prefix:<~>
the same as
$moose.coerce:<as>(Str)
for instance?

And forgive my brain, but how would you nicely define coercion in a class?
Like, could you spare an example?

Also, what's the point of making a whole grammatical category for "coerce"
that behaves like an infix operator?

Thanks in advance.

[Larry Wall]

On Mon, Apr 03, 2006 at 07:23:28PM -0700, Joshua Choi wrote:
: Kudos to all on the Perl 6 mailing list,

:
: What's the conceptual difference (or relationship) between context and type
: coercion? Is
: $moose.prefix:<~>
: the same as
: $moose.coerce:<as>(Str)
: for instance?

No difference.

: And forgive my brain, but how would you nicely define coercion in a class?

: Like, could you spare an example?

Currently something like:

multi submethod infix:<as> ($self: Str) {...}
multi submethod infix:<as> ($self: Int) {...}

or

multi sub infix:<as> (MyClass $self, Str) {...}
multi sub infix:<as> (MyClass $self, Int) {...}

: Also, what's the point of making a whole grammatical category for "coerce"

: that behaves like an infix operator?

In the current synopses there is no "coerce" grammatical category
any more. Everything is subsumed under infix:<as>, at least this week...
There's some discussion about whether it should simply be:

method as (Str) {...}
method as (Int) {...}

maybe with an "is deep" thrown in for good measure, but we haven't
quite got there yet.

Larry

[Larry Wall]

On Mon, Apr 03, 2006 at 08:24:51PM -0700, Larry Wall wrote:
: There's some discussion about whether it should simply be:

:
: method as (Str) {...}
: method as (Int) {...}
:
: maybe with an "is deep" thrown in for good measure, but we haven't
: quite got there yet.

Er, to have multiple of them in the same class, that would of course
have to be:

multi method as (Str) {...}
multi method as (Int) {...}

Generally, I love to travel. Specifically, I love the fact that
jet lag is a such a convenient excuse for stupidity.

Larry