[FAQ] schema lambda support

[wilsonwang371]

General Question

is it possible to support schema lambdas (class methods) in kcl. we can have a self keyword which can be used to access a readonly instance.

[Peefy]

In fact, KCL currently supports defining member functions for schemas and can omit self.

schema Person:
    firstName: str
    lastName: str
    getFullName: () -> str = lambda {
        firstName + " " + lastName
    }

p = Person{
    firstName = "Alice"
    lastName = "White"
}
fullName = p.getFullName()

The output is

p:
  firstName: Alice
  lastName: White
fullName: Alice White

Of course, this is not as complex in configuration languages, just defining it is enough.

schema Person:
    firstName: str
    lastName: str
    fullName: str = firstName + " " + lastName

p = Person{
    firstName = "Alice"
    lastName = "White"
}
fullName = p.fullName

[wilsonwang371]

Is it possible to support

    getFullName = lambda {
        firstName + " " + lastName
    }

as well?

[Peefy]

This is possible, but in KCL, schema members without type annotations are treated as private.

[wilsonwang371]

this is not very straightforward. can we have something like underscore in python or upper/lower case in golang. i know this already conflict with current version.

[Peefy]

Make sense. We are exploring the possibility of simplifying KCL and clarifying its semantics. Perhaps this situation will change in future versions. In addition, we will also provide more user-friendly prompt information for additional enhancements.

[d4v1d03]

Hey @Peefy , made the PR #377