Speaking of `equals` and `hashcode`, can we change...

# language-proposals

[andrewoma]

Speaking of equals and hashcode, can we change the generated functions to be less ugly. Here's a generated example:

class Foo(val bar: String, val baz: Int, val quz: String?) {
    override fun equals(other: Any?): Boolean{
        if (this === other) return true
        if (other !is Foo) return false

        if (bar != other.bar) return false
        if (baz != other.baz) return false
        if (quz != other.quz) return false

        return true
    }

    override fun hashCode(): Int{
        var result = bar.hashCode()
        result += 31 * result + baz
        result += 31 * result + (quz?.hashCode() ?: 0)
        return result
    }
}

And here's something like what I'm after:

class Foo2(val bar: String, val baz: Int, val quz: String?) {
    override fun equals(other: Any?) = equals(this, other) { o1, o2 ->
        return o1.bar == o2.bar && o1.baz == o2.baz && o1.quz == o2.quz
    }

    override fun hashCode() = Objects.hash(bar, baz, quz)
}

Using the generic:

inline fun <reified T> equals(t: T, other: Any?, equate: (t1: T, t2: T) -> Boolean): Boolean {
    if (t === other) return true
    if (other !is T) return false
    return equate(t, other)
}