The Issue with the Current Implementation

Oct 13, 2025 by miodeya.com 46 views

Summary

Description

The column() method in CollectionInterface has been updated to return the same collection as the original collection. However, the current implementation in AbstractCollection returns a collection with the type of the property or method requested. This is not possible for regular use, as the type of the property or method requested may not be the same as the type of the collection.

<?php

class Inner {
    protected string $name;
}

/** @var Collection<Inner> */
$collection = new Collection(Inner::class);

// $names will have type Collection<Inner>, instead of Collection<string>
$names = $collection->column('name');

In the above example, the $names variable will have a type of Collection<Inner>, instead of Collection<string>. This is because the column() method returns a collection with the type of the property or method requested, which is Inner in this case.

Expected Behavior

The expected behavior of the column() method is to return either an untyped return, because the type cannot be extracted based on the property name or method, or an actual type which is not the type of the Collection, but the type of the property or method.

Environment Details

Package version: 2.1.0
PHP version: 8.3.13
OS: macOS Sonoma (14.7)

The Issue with the Current Implementation

The current implementation of the column() method in AbstractCollection returns a collection with the type of the property or method requested. This is not possible for regular use, as the type of the property or method requested may not be the same as the type of the collection.

For example, in the above example, the $names variable will have a type of Collection<Inner>, instead of Collection<string>. This is because the column() method returns a collection with the type of the property or method requested, which is Inner in this case.

Why the Current Implementation is Not Possible

Possible Solutions

There are several possible solutions to this issue:

Return an untyped return, because the type cannot be extracted based on the property name or method.
Return an actual type which is not the type of the Collection, but the type of the property or method.
Modify the column() method to return a collection with the correct type.

Conclusion

The column() method in CollectionInterface is expected to return the same collection as the original collection. However, the current implementation returns a collection with the type of the property or method requested, which is not possible for regular use. There are several possible solutions to this issue, including returning an untyped return, returning an actual type which is not the type of the Collection, but the type of the property or method, or modifying the column() method to return a collection with the correct type.

Recommendations

Based on the analysis of the issue, the following recommendations are made:

Modify the column() method to return a collection with the correct type.
Return an untyped return, because the type cannot be extracted based on the property name or method.
Return an actual type which is not the type of the Collection, but the type of the property or method.

Future Work

The future work for this issue includes:

Modifying the column() method to return a collection with the correct type.
Returning an untyped return, because the type cannot be extracted based on the property name or method.
Returning an actual type which is not the type of the Collection, but the type of the property or method.

References

Appendix

The following is an example of how the column() method could be modified to return a collection with the correct type:

<?php

class Inner {
    protected string $name;
}

/** @var Collection<Inner> */
$collection = new Collection(Inner::class);

// $names will have type Collection<string>
$names = $collection->column('name');

Q: What is the issue with the `column()` method in `CollectionInterface`?

A: The column() method in CollectionInterface is expected to return the same collection as the original collection. However, the current implementation returns a collection with the type of the property or method requested, which is not possible for regular use.

Q: Why is the current implementation not possible for regular use?

A: The current implementation of the column() method in AbstractCollection returns a collection with the type of the property or method requested. This is not possible for regular use, as the type of the property or method requested may not be the same as the type of the collection.

Q: What are the possible solutions to this issue?

A: There are several possible solutions to this issue:

Return an untyped return, because the type cannot be extracted based on the property name or method.
Return an actual type which is not the type of the Collection, but the type of the property or method.
Modify the column() method to return a collection with the correct type.

Q: How can the `column()` method be modified to return a collection with the correct type?

A: The column() method can be modified to return a collection with the correct type by changing the return type of the method to the type of the property or method requested. For example:

<?php

class Inner {
    protected string $name;
}

/** @var Collection<Inner> */
$collection = new Collection(Inner::class);

// $names will have type Collection<string>
$names = $collection->column('name');

In this example, the $names variable will have a type of Collection<string>, instead of Collection<Inner>. This is because the column() method has been modified to return a collection with the correct type.

Q: What are the benefits of modifying the `column()` method to return a collection with the correct type?

A: The benefits of modifying the column() method to return a collection with the correct type include:

Improved type safety: By returning a collection with the correct type, the column() method can provide improved type safety for users of the method.
Easier debugging: With a collection of the correct type, debugging can be easier and more efficient.
Improved code readability: The code will be more readable and easier to understand when the column() method returns a collection with the correct type.

Q: What are the potential drawbacks of modifying the `column()` method to return a collection with the correct type?

A: The potential drawbacks of modifying the column() method to return a collection with the correct type include:

Increased complexity: Modifying the column() method to return a collection with the correct type can increase the complexity of the method.
Potential performance issues: Depending on the implementation, modifying the column() method to return a collection with the correct type can potentially lead to performance issues.

Q: How can the `column()` method be modified to return an untyped return?

A: The column() method can be modified to return an untyped return by changing the return type of the method to mixed or array. For example:

<?php

class Inner {
    protected string $name;
}

/** @var Collection<Inner> */
$collection = new Collection(Inner::class);

// $names will have type mixed
$names = $collection->column('name');

In this example, the $names variable will have a type of mixed, instead of Collection<Inner>. This is because the column() method has been modified to return an untyped return.

Q: What are the benefits of modifying the `column()` method to return an untyped return?

A: The benefits of modifying the column() method to return an untyped return include:

Simplified implementation: By returning an untyped return, the column() method can be simplified and made easier to implement.
Improved performance: Depending on the implementation, returning an untyped return can potentially lead to improved performance.
Easier debugging: With an untyped return, debugging can be easier and more efficient.

Q: What are the potential drawbacks of modifying the `column()` method to return an untyped return?

A: The potential drawbacks of modifying the column() method to return an untyped return include:

Reduced type safety: By returning an untyped return, the column() method can provide reduced type safety for users of the method.
Potential errors: Depending on the implementation, returning an untyped return can potentially lead to errors.
Reduced code readability: The code will be less readable and more difficult to understand when the column() method returns an untyped return.