This file is automatically generated. If you wish to submit a PR, do not
edit this file directly. Please edit
templates/rfc/mvp.md instead. Use bin/generate_rfc.pl to regenerate the RFCs.
The Corinna MVP has been accepted by The Perl Steering Committee and work on integrating Corinna into the Perl core has begun.
This is an MMVP (Minimally Minimal Viable Product). This is written after guidance provided by the Perl Steering committee. This addresses a few concerns.
- The more we push into core, the more bugs there will be
- The more we push into core, the more time it will take
- The more we push into core, the more people might rely on misfeatures
Thus, Corinna development for core will be staged, with subsequent work to realize the full MVP.
Thus, we want the simplest thing that could possibly work in the first release.
What follows is a minimal description of what we'd like for the MMVP. The plan is to implement this in seven stages. Each stage will be pushed separately, giving us time to test and verify that it does what we need. Note that some features are specified, in terms of semantics, but in the spirit of "no plan survives first contact with the enemy," we will nail some of the syntax down as we write tests to verify the behavior and solicit feedback from those playing with it.
Initial use feature 'class' to add basic class, field, and method keywords.
This will include ADJUST and ADJUSTPARAMS phasers.
No roles, no class/field/method attributes, no MOP.
Single-inheritance only.
class Employee :isa(Person) {
field $employee_id :param;
}
role Role::Created {
field $created :reader = time;
}
class SomeClass :does(Role::Created) {
...
}
Note: for roles, the current implementation of required methods is to simply
create a forward declaration: method foo; without listing the signature.
Signatures are currently not introspectable, so we cannot use them to verify
that the correct required method is present, so we only use the name.
Including a signature in the forward declaration might be self-documenting,
but for now, we'd prefer to omit it because this might impact forward
compatibility.
field :reader :writer :accessor :mutator
field :weak
field :param
method :overrides()
At this stage, most of the basics are in place and we have a useful system.
A postfix { expression } block on a field can set its default value.
field $answer :param = 42;
The metaobject protocol, similar to Class::MOP.
They behave similarly to the around, before, and after method modifiers
from Moo/se.
Obviously, quite a few features are missing from this RFC of Corinna. Our intent is to roll them out as quickly as is feasible, but to ensure the foundation is stable.
The following features are not planned for the MMVP and might break your code in subsequent releases.
- Error on unknown constructor parameters
- Deterministic destruction might cause issues when introduced
- Many other features (see the github repo)
There are a ton of other feature omitted, but have been not mentioned here because they're not even part of the Corinna MVP (role exclusion and aliasing being a perfect example).