We can all agree that the "silently accept null" approach is, by now, a quadrillion dollar mistake.
But having a safe "or null" union type as the _only_ union type in your language, isn't as far fetched as you make it sound.
It's the good old "allow zero, one or an infinite amount of any feature" rule. Sometimes "one" is the right choice.
And the same principle applies to values. A plain value is one value. A list/collection is an arbitrary number of values. And `null` is no value. Some would, rightly, say that `void` is no value, so `null` it's really a value representing no value.
And then you will also want to represent zero-or-one value, which is where the -or-null type comes in.
This is a more fundamental union than just "a Foo or a Bar" which is always a value, then we're just arguing over type.
You can always use an `Option` class instead. If you have classes. But if you're going to use `Option.none` to represent the value of an uninitialized variable, you're going to build it into the language anyway, and then you might as well admit to that one union type.
We can all agree that the "silently accept null" approach is, by now, a quadrillion dollar mistake.
But having a safe "or null" union type as the _only_ union type in your language, isn't as far fetched as you make it sound.
It's the good old "allow zero, one or an infinite amount of any feature" rule. Sometimes "one" is the right choice.
And the same principle applies to values. A plain value is one value. A list/collection is an arbitrary number of values. And `null` is no value. Some would, rightly, say that `void` is no value, so `null` it's really a value representing no value. And then you will also want to represent zero-or-one value, which is where the -or-null type comes in.
This is a more fundamental union than just "a Foo or a Bar" which is always a value, then we're just arguing over type.
You can always use an `Option` class instead. If you have classes. But if you're going to use `Option.none` to represent the value of an uninitialized variable, you're going to build it into the language anyway, and then you might as well admit to that one union type.