text: // run
  
  // Copyright 2009 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.
  
  // Test interfaces and methods.
  
  package main
  
  type S struct {
  	a,b	int;
  }
  
  type I1 interface {
  	f	()int;
  }
  
  type I2 interface {
  	g() int;
  	f() int;
  }
  
  func (this *S) f()int {
  	return this.a;
  }
  
  func (this *S) g()int {
  	return this.b;
  }
  
  func
  main() {
  	var i1 I1;
  	var i2 I2;
  	var g *S;
  
  	s := new(S);
  	s.a = 5;
  	s.b = 6;
  
  	// call structure
  	if s.f() != 5 { panic(11); }
  	if s.g() != 6 { panic(12); }
  
  	i1 = s;		// convert S to I1
  	i2 = i1.(I2);	// convert I1 to I2
  
  	// call interface
  	if i1.f() != 5 { panic(21); }
  	if i2.f() != 5 { panic(22); }
  	if i2.g() != 6 { panic(23); }
  
  	g = i1.(*S);		// convert I1 to S
  	if g != s { panic(31); }
  
  	g = i2.(*S);		// convert I2 to S
  	if g != s { panic(32); }
  }
  