37 replies

Why is the first Type Parameter of a Schema `never`?

Why is the first type Parameter of some Schema always (or by default) never? For Instance:

const Foo = S.struct({ name: S.string })

const Foo = S.struct({ name: S.string })

const Foo = S.struct({ name: S.string })

const Foo = S.struct({ name: S.string })

const Foo: S.Schema<never, {
    readonly name: string;
}, {
    readonly name: string;
}>

const Foo: S.Schema<never, {
    readonly name: string;
}, {
    readonly name: string;
}>

const Foo: S.Schema<never, {
    readonly name: string;
}, {
    readonly name: string;
}>

const Foo: S.Schema<never, {
    readonly name: string;
}, {
    readonly name: string;
}>

I can't really figure out how to define an Schema, that it meant to convert from

string

string

string

string to

Foo

Foo

Foo

Foo . Somehow I cannot get my Head around how that is meant to work.