// run -gcflags=-G=3 // Copyright 2021 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package main import "fmt" type Exp[Ty any] interface { Eval() Ty } type Lit[Ty any] Ty func (lit Lit[Ty]) Eval() Ty { return Ty(lit) } func (lit Lit[Ty]) String() string { return fmt.Sprintf("(lit %v)", Ty(lit)) } type Eq[Ty any] struct { a Exp[Ty] b Exp[Ty] } func (e Eq[Ty]) String() string { return fmt.Sprintf("(eq %v %v)", e.a, e.b) } var ( e0 = Eq[int]{Lit[int](128), Lit[int](64)} e1 = Eq[bool]{Lit[bool](true), Lit[bool](true)} ) func main() { fmt.Printf("%v\n", e0) fmt.Printf("%v\n", e1) }