index.tp

typp TGen<T> = Foo<Names extends T> -> { name: Names }

typp TStr = TGen<string>
// Compiles
type TStr<Names extends string> = { name: Names }

typp T1Or2 = TGen<1 | 2>
// Compiles
type T1Or2<Names extends 1 | 2> = { name: Names }

typp GenericParams = [T extends string, U extends number]

interface Foo<...GenericParams> { name: T, age: U }
// Compiles
interface Foo<T extends string, U extends number> { name: T, age: U }

t(String)
// string
t(Number)
// number
or('1', '2')
// '1' | '2'
or('1', String)
// '1' | (string & {})
and(t({ a: String }), t({ b: Number }))
// { a: string } & { b: number }
const keys = or('oa', 'ob', 'c')
and(keys, t`o${String}`)
// 'oa' | 'ob'

t([ String, Number ])
// [string, number]
t([], String)
// string[]
t([], [], Number)
// number[][]

t({}, String, Number)
// { [x: string]: number }
t({}, String, {}, String, Number)
// { [x: string]: { [x: string]: number } }
t({}, {}, String, Number)
// { [x: PropertyKey]: { [x: string]: number } }

t({ name: String })
// { name: string }

t(Map, String, Number)
// Map<string, number>

t(Set, String)
// Set<string>

t(Promise, String)
// Promise<string>

t(Function, [], String)
// () => string
t(Function, [ String ], Number)
// (a: string) => number
t(Function, [ ], Function, [ String ], Number)
// () => (a: string) => number

t(Function, [ {} ], is(String))
// (a: any) => a is string

t((a = String) => Number)
// (a: string) => number
t((a = {}) => is(String))
// (a: any) => a is string

t((a = generic('T')) => or(a, String))
// <T>(a: T) => T | (string & {})
t((a = generic('T', String)) => or(a, String))
// <T extends string>(a: T) => T | (string & {})