How to assign two slices containing different types?

[listepo]

For example:

type Copygen interface {
	ToCurrenciesContract(m []*models.Currency) []*contracts.Currency
}

generates:

// ToCurrenciesContract copies a []*models.Currency to a []*contracts.Currency.
func ToCurrenciesContract(tc []*contracts.Currency, fm []*models.Currency) {
	// []*contracts.Currency fields
}

[switchupcb]

You want to generate a function that converts all from objects []*models.Currency to []*contracts.Currency.

• []*models.Currency is a slice of struct pointers to a models.Currency struct.
• []*contracts.Currency is a slice of struct pointers to a contracts.Currency struct.
• These types are not equivalent and won't be assigned to each other by default.

There are multiple interpretations of the request to assign a slice of one type to a slice of another type.

1. For each item in each slice, assign the respective fields from contracts.Currency to models.Currency.
2. For each item in each slice, assign the respective interface contracts.Currency to models.Currency object (using type conversion).
3. For each item in each slice, assign the respective object contracts.Currency to interface models.Currency.
4. Any variation thereof...

Implementing a solution to any interpretation requires use of type conversion or assertion.

Implementation

v0.4

Use the convert option to implement this functionality.

convert

type Copygen interface {
	ToCurrenciesContract(m []*models.Currency) []*contracts.Currency
}

/* Define the function and field this converter is applied to using regex. */
// convert .* \[\]\*models.Currency
// ModelCurrenciesToContractCurrencies converts a slice of model currencies to a slice of contract currencies.
func ModelCurrenciesToContractCurrencies(m []*models.Currency) []*contracts.Currency{
        var output []*contracts.Currency

        // Your implementation according to the interpretation above goes here...

	return output
}

Need more information on the convert option? Check out the convert demonstration in the main example.

This should generate the following code.

// ToCurrenciesContract copies a []*models.Currency to a []*contracts.Currency.
func ToCurrenciesContract(tc []*contracts.Currency, fm []*models.Currency) {
	// []*contracts.Currency fields
       tc = ModelCurrenciesToContractCurrencies(fm)
}

If not, please report this problem in the issue tracker.

v0.5

Use the cast option to implement this functionality with an existing conversion function.

cast

Coming soon.

[listepo]

@switchupcb thank you a lot

[switchupcb]

@listepo I have updated my example to replace the following lines.

// convert .* \[\]\*models.Currency

This is because the first field of a convert option specifies which functions the conversion function is used in, and the second specifies which fields the function will be used on.