Editando: method5.go
// run // Copyright 2013 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 // Concrete types implementing M method. // Smaller than a word, word-sized, larger than a word. // Value and pointer receivers. type Tinter interface { M(int, byte) (byte, int) } type Tsmallv byte func (v Tsmallv) M(x int, b byte) (byte, int) { return b, x+int(v) } type Tsmallp byte func (p *Tsmallp) M(x int, b byte) (byte, int) { return b, x+int(*p) } type Twordv uintptr func (v Twordv) M(x int, b byte) (byte, int) { return b, x+int(v) } type Twordp uintptr func (p *Twordp) M(x int, b byte) (byte, int) { return b, x+int(*p) } type Tbigv [2]uintptr func (v Tbigv) M(x int, b byte) (byte, int) { return b, x+int(v[0])+int(v[1]) } type Tbigp [2]uintptr func (p *Tbigp) M(x int, b byte) (byte, int) { return b, x+int(p[0])+int(p[1]) } // Again, with an unexported method. type tsmallv byte func (v tsmallv) m(x int, b byte) (byte, int) { return b, x+int(v) } type tsmallp byte func (p *tsmallp) m(x int, b byte) (byte, int) { return b, x+int(*p) } type twordv uintptr func (v twordv) m(x int, b byte) (byte, int) { return b, x+int(v) } type twordp uintptr func (p *twordp) m(x int, b byte) (byte, int) { return b, x+int(*p) } type tbigv [2]uintptr func (v tbigv) m(x int, b byte) (byte, int) { return b, x+int(v[0])+int(v[1]) } type tbigp [2]uintptr func (p *tbigp) m(x int, b byte) (byte, int) { return b, x+int(p[0])+int(p[1]) } type tinter interface { m(int, byte) (byte, int) } // Embedding via pointer. type T1 struct { T2 } type T2 struct { *T3 } type T3 struct { *T4 } type T4 struct { } func (t4 T4) M(x int, b byte) (byte, int) { return b, x+40 } var failed = false func CheckI(name string, i Tinter, inc int) { b, x := i.M(1000, 99) if b != 99 || x != 1000+inc { failed = true print(name, ".M(1000, 99) = ", b, ", ", x, " want 99, ", 1000+inc, "\n") } CheckF("(i="+name+")", i.M, inc) } func CheckF(name string, f func(int, byte) (byte, int), inc int) { b, x := f(1000, 99) if b != 99 || x != 1000+inc { failed = true print(name, "(1000, 99) = ", b, ", ", x, " want 99, ", 1000+inc, "\n") } } func checkI(name string, i tinter, inc int) { b, x := i.m(1000, 99) if b != 99 || x != 1000+inc { failed = true print(name, ".m(1000, 99) = ", b, ", ", x, " want 99, ", 1000+inc, "\n") } checkF("(i="+name+")", i.m, inc) } func checkF(name string, f func(int, byte) (byte, int), inc int) { b, x := f(1000, 99) if b != 99 || x != 1000+inc { failed = true print(name, "(1000, 99) = ", b, ", ", x, " want 99, ", 1000+inc, "\n") } } func shouldPanic(f func()) { defer func() { if recover() == nil { panic("not panicking") } }() f() } func shouldNotPanic(f func()) { f() } func main() { sv := Tsmallv(1) CheckI("sv", sv, 1) CheckF("sv.M", sv.M, 1) CheckF("(&sv).M", (&sv).M, 1) psv := &sv CheckI("psv", psv, 1) CheckF("psv.M", psv.M, 1) CheckF("(*psv).M", (*psv).M, 1) sp := Tsmallp(2) CheckI("&sp", &sp, 2) CheckF("sp.M", sp.M, 2) CheckF("(&sp).M", (&sp).M, 2) psp := &sp CheckI("psp", psp, 2) CheckF("psp.M", psp.M, 2) CheckF("(*psp).M", (*psp).M, 2) wv := Twordv(3) CheckI("wv", wv, 3) CheckF("wv.M", wv.M, 3) CheckF("(&wv).M", (&wv).M, 3) pwv := &wv CheckI("pwv", pwv, 3) CheckF("pwv.M", pwv.M, 3) CheckF("(*pwv).M", (*pwv).M, 3) wp := Twordp(4) CheckI("&wp", &wp, 4) CheckF("wp.M", wp.M, 4) CheckF("(&wp).M", (&wp).M, 4) pwp := &wp CheckI("pwp", pwp, 4) CheckF("pwp.M", pwp.M, 4) CheckF("(*pwp).M", (*pwp).M, 4) bv := Tbigv([2]uintptr{5, 6}) pbv := &bv CheckI("bv", bv, 11) CheckF("bv.M", bv.M, 11) CheckF("(&bv).M", (&bv).M, 11) CheckI("pbv", pbv, 11) CheckF("pbv.M", pbv.M, 11) CheckF("(*pbv).M", (*pbv).M, 11) bp := Tbigp([2]uintptr{7,8}) CheckI("&bp", &bp, 15) CheckF("bp.M", bp.M, 15) CheckF("(&bp).M", (&bp).M, 15) pbp := &bp CheckI("pbp", pbp, 15) CheckF("pbp.M", pbp.M, 15) CheckF("(*pbp).M", (*pbp).M, 15) _sv := tsmallv(1) checkI("_sv", _sv, 1) checkF("_sv.m", _sv.m, 1) checkF("(&_sv).m", (&_sv).m, 1) _psv := &_sv checkI("_psv", _psv, 1) checkF("_psv.m", _psv.m, 1) checkF("(*_psv).m", (*_psv).m, 1) _sp := tsmallp(2) checkI("&_sp", &_sp, 2) checkF("_sp.m", _sp.m, 2) checkF("(&_sp).m", (&_sp).m, 2) _psp := &_sp checkI("_psp", _psp, 2) checkF("_psp.m", _psp.m, 2) checkF("(*_psp).m", (*_psp).m, 2) _wv := twordv(3) checkI("_wv", _wv, 3) checkF("_wv.m", _wv.m, 3) checkF("(&_wv).m", (&_wv).m, 3) _pwv := &_wv checkI("_pwv", _pwv, 3) checkF("_pwv.m", _pwv.m, 3) checkF("(*_pwv).m", (*_pwv).m, 3) _wp := twordp(4) checkI("&_wp", &_wp, 4) checkF("_wp.m", _wp.m, 4) checkF("(&_wp).m", (&_wp).m, 4) _pwp := &_wp checkI("_pwp", _pwp, 4) checkF("_pwp.m", _pwp.m, 4) checkF("(*_pwp).m", (*_pwp).m, 4) _bv := tbigv([2]uintptr{5, 6}) _pbv := &_bv checkI("_bv", _bv, 11) checkF("_bv.m", _bv.m, 11) checkF("(&_bv).m", (&_bv).m, 11) checkI("_pbv", _pbv, 11) checkF("_pbv.m", _pbv.m, 11) checkF("(*_pbv).m", (*_pbv).m, 11) _bp := tbigp([2]uintptr{7,8}) checkI("&_bp", &_bp, 15) checkF("_bp.m", _bp.m, 15) checkF("(&_bp).m", (&_bp).m, 15) _pbp := &_bp checkI("_pbp", _pbp, 15) checkF("_pbp.m", _pbp.m, 15) checkF("(*_pbp).m", (*_pbp).m, 15) t4 := T4{} t3 := T3{&t4} t2 := T2{&t3} t1 := T1{t2} CheckI("t4", t4, 40) CheckI("&t4", &t4, 40) CheckI("t3", t3, 40) CheckI("&t3", &t3, 40) CheckI("t2", t2, 40) CheckI("&t2", &t2, 40) CheckI("t1", t1, 40) CheckI("&t1", &t1, 40) // x.M panics if x is an interface type and is nil, // or if x.M expands to (*x).M where x is nil, // or if x.M expands to x.y.z.w.M where something // along the evaluation of x.y.z.w is nil. var f func(int, byte) (byte, int) shouldPanic(func() { psv = nil; f = psv.M }) shouldPanic(func() { pwv = nil; f = pwv.M }) shouldPanic(func() { pbv = nil; f = pbv.M }) shouldPanic(func() { var i Tinter; f = i.M }) shouldPanic(func() { _psv = nil; f = _psv.m }) shouldPanic(func() { _pwv = nil; f = _pwv.m }) shouldPanic(func() { _pbv = nil; f = _pbv.m }) shouldPanic(func() { var _i tinter; f = _i.m }) shouldPanic(func() { var t1 T1; f = t1.M }) shouldPanic(func() { var t2 T2; f = t2.M }) shouldPanic(func() { var t3 *T3; f = t3.M }) shouldPanic(func() { var t3 T3; f = t3.M }) if f != nil { panic("something set f") } // x.M does not panic if x is a nil pointer and // M is a method with a pointer receiver. shouldNotPanic(func() { psp = nil; f = psp.M }) shouldNotPanic(func() { pwp = nil; f = pwp.M }) shouldNotPanic(func() { pbp = nil; f = pbp.M }) shouldNotPanic(func() { _psp = nil; f = _psp.m }) shouldNotPanic(func() { _pwp = nil; f = _pwp.m }) shouldNotPanic(func() { _pbp = nil; f = _pbp.m }) shouldNotPanic(func() { var t4 T4; f = t4.M }) if f == nil { panic("nothing set f") } }
Cancelar
Kerym Chaeceran