Body macros on properties

[cal (Cal Stephens)]

@cal

A use case I personally have in mind is being able to generate an accessor that uses the name of the attached declaration:

@Generate var myCustomElement: ElementID

// Expands to:
var myCustomElement: ElementID { ElementID(name: "myCustomElement") }

I see, this is already supported using an accessor macro:

@Douglas_Gregor

@joshw

Could computed variables be declared via the "no-body" syntax functions can be declared with?

For example:

extension MyType {
    @Foo var name: String

    // expands to
    var name: String {
        "Foo"
    } 
}

(note this is in an extension so a stored property wouldn't be allowed here but leaving out the curly braces after the definition is more readable than not)

No, replacing a stored property with a computed property requires an accessor macro.

Makes sense that we don’t need to duplicate this capability via body macros.

The open question for how to support VariableDeclSyntax in BodyMacro.expansion remains, but may only be an implementation detail.