How are booleans in Gleam represented?

[CrowdHailer]

There are typed expressions for other literals such as Int/Float. But as far as I can see not a similar expression for Booleans

gleam/src/erl.rs

Lines 1420 to 1422 in 87f3bb0

	TypedExpr::Int { value, .. } => int(value),
	TypedExpr::Float { value, .. } => float(value),
	TypedExpr::String { value, .. } => string(value),

How are Booleans represented?

[lpil]

Booleans are not a primitive type with a dedicated literal syntax, they're just a normal custom type but defined in the prelude.

pub type Bool {
  True
  False
}

[CrowdHailer]

When printing the erlang I guess this works because a type without fields just gets generated as an atom. and the atom true/false is the same as idiomatic erlang booleans.

I think for the JS, I'm going to have to recognise this prelude record and choose to render them as JS bools for interop.

Is the same true for Nil, i.e. it's a single variant record that helpfully gets output as the relevant nil atom.

[lpil]

Yup we'd want to render something special for bools and nil, likely true, false and undefined. We can do this by checking the type of the constructor and seeing if it's the prelude Bool or Nil respectively

[Rudxain]

This is genuinely beautiful. I wish Rust bools were just 2-variant enums, although this may have some caveats in that lang (unless fixed by special traits)

I just learned that Ada does it too!:

type Boolean is (False, True);