carbon-lang/executable_semantics/testdata/interface/vector_point_add_scale.carbon

// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
// RUN: %{executable_semantics} %s 2>&1 | \
// RUN:   %{FileCheck} --match-full-lines --allow-unused-prefixes=false %s
// RUN: %{executable_semantics} --trace %s 2>&1 | \
// RUN:   %{FileCheck} --match-full-lines --allow-unused-prefixes %s
// AUTOUPDATE: %{executable_semantics} %s
// CHECK: result: 0

package ExecutableSemanticsTest api;

interface Vector {
  fn Add[me: Self](b: Self) -> Self;
  fn Scale[me: Self](v: i32) -> Self;
}

class Point {
  var x: i32;
  var y: i32;
  impl Point as Vector {
    fn Add[me: Point](b: Point) -> Point {
        return {.x = me.x + b.x, .y = me.y + b.y};
    }
    fn Scale[me: Point](v: i32) -> Point {
        return {.x = me.x * v, .y = me.y * v};
    }
  }
}

fn AddAndScaleGeneric[T:! Vector](a: T, b: T, s: i32) -> T {
  var m: __Fn(T)->T = a.Add;
  var n: __Fn(i32)->T = m(b).Scale;
  return n(s);
}

fn Main() -> i32 {
  var a: Point = {.x = 1, .y = 1};
  var b: Point = {.x = 2, .y = 3};
  var p: Point = AddAndScaleGeneric(a, b, 5);
  return p.x - 15;
}