mirror of
https://github.com/golang/go
synced 2024-11-26 02:17:58 -07:00
cmd/compile/internal/types2: disallow lone type parameter on RHS of type declaration
We may revisit this decision in a future release. By disallowing this for Go 1.18 we are ensuring that we don't lock in the generics design in a place that may need to change later. (Type declarations are the primary construct where it crucially matters what the underlying type of a type parameter is.) Comment out all tests that rely on this feature; add comments referring to issue so we can find all places easily should we change our minds. Fixes #45639. Change-Id: I730510e4da66d3716d455a9071c7778a1e4a1152 Reviewed-on: https://go-review.googlesource.com/c/go/+/359177 Trust: Robert Griesemer <gri@golang.org> Trust: Dan Scales <danscales@google.com> Reviewed-by: Dan Scales <danscales@google.com>
This commit is contained in:
parent
79ff663754
commit
a91d0b649c
@ -622,13 +622,6 @@ func TestDefsInfo(t *testing.T) {
|
||||
{`package p3; type x int`, `x`, `type p3.x int`},
|
||||
{`package p4; func f()`, `f`, `func p4.f()`},
|
||||
{`package p5; func f() int { x, _ := 1, 2; return x }`, `_`, `var _ int`},
|
||||
|
||||
// generic types must be sanitized
|
||||
// (need to use sufficiently nested types to provoke unexpanded types)
|
||||
{genericPkg + `g0; type t[P any] P; const x = t[int](42)`, `x`, `const generic_g0.x generic_g0.t[int]`},
|
||||
{genericPkg + `g1; type t[P any] P; var x = t[int](42)`, `x`, `var generic_g1.x generic_g1.t[int]`},
|
||||
{genericPkg + `g2; type t[P any] P; type x struct{ f t[int] }`, `x`, `type generic_g2.x struct{f generic_g2.t[int]}`},
|
||||
{genericPkg + `g3; type t[P any] P; func f(x struct{ f t[string] }); var g = f`, `g`, `var generic_g3.g func(x struct{f generic_g3.t[string]})`},
|
||||
}
|
||||
|
||||
for _, test := range tests {
|
||||
@ -667,13 +660,6 @@ func TestUsesInfo(t *testing.T) {
|
||||
{`package p2; func _() { _ = x }; var x int`, `x`, `var p2.x int`},
|
||||
{`package p3; func _() { type _ x }; type x int`, `x`, `type p3.x int`},
|
||||
{`package p4; func _() { _ = f }; func f()`, `f`, `func p4.f()`},
|
||||
|
||||
// generic types must be sanitized
|
||||
// (need to use sufficiently nested types to provoke unexpanded types)
|
||||
{genericPkg + `g0; func _() { _ = x }; type t[P any] P; const x = t[int](42)`, `x`, `const generic_g0.x generic_g0.t[int]`},
|
||||
{genericPkg + `g1; func _() { _ = x }; type t[P any] P; var x = t[int](42)`, `x`, `var generic_g1.x generic_g1.t[int]`},
|
||||
{genericPkg + `g2; func _() { type _ x }; type t[P any] P; type x struct{ f t[int] }`, `x`, `type generic_g2.x struct{f generic_g2.t[int]}`},
|
||||
{genericPkg + `g3; func _() { _ = f }; type t[P any] P; func f(x struct{ f t[string] })`, `f`, `func generic_g3.f(x struct{f generic_g3.t[string]})`},
|
||||
}
|
||||
|
||||
for _, test := range tests {
|
||||
|
@ -604,9 +604,12 @@ func (check *Checker) typeDecl(obj *TypeName, tdecl *syntax.TypeDecl, def *Named
|
||||
named.underlying = Typ[Invalid]
|
||||
}
|
||||
|
||||
// If the RHS is a type parameter, it must be from this type declaration.
|
||||
if tpar, _ := named.underlying.(*TypeParam); tpar != nil && tparamIndex(named.TypeParams().list(), tpar) < 0 {
|
||||
check.errorf(tdecl.Type, "cannot use function type parameter %s as RHS in type declaration", tpar)
|
||||
// Disallow a lone type parameter as the RHS of a type declaration (issue #45639).
|
||||
// We can look directly at named.underlying because even if it is still a *Named
|
||||
// type (underlying not fully resolved yet) it cannot become a type parameter due
|
||||
// to this very restriction.
|
||||
if tpar, _ := named.underlying.(*TypeParam); tpar != nil {
|
||||
check.error(tdecl.Type, "cannot use a type parameter as RHS in type declaration")
|
||||
named.underlying = Typ[Invalid]
|
||||
}
|
||||
}
|
||||
|
@ -4,8 +4,6 @@
|
||||
|
||||
package linalg
|
||||
|
||||
import "math"
|
||||
|
||||
// Numeric is type bound that matches any numeric type.
|
||||
// It would likely be in a constraints package in the standard library.
|
||||
type Numeric interface {
|
||||
@ -52,32 +50,33 @@ type Complex interface {
|
||||
~complex64 | ~complex128
|
||||
}
|
||||
|
||||
// OrderedAbs is a helper type that defines an Abs method for
|
||||
// ordered numeric types.
|
||||
type OrderedAbs[T OrderedNumeric] T
|
||||
|
||||
func (a OrderedAbs[T]) Abs() OrderedAbs[T] {
|
||||
if a < 0 {
|
||||
return -a
|
||||
}
|
||||
return a
|
||||
}
|
||||
|
||||
// ComplexAbs is a helper type that defines an Abs method for
|
||||
// complex types.
|
||||
type ComplexAbs[T Complex] T
|
||||
|
||||
func (a ComplexAbs[T]) Abs() ComplexAbs[T] {
|
||||
r := float64(real(a))
|
||||
i := float64(imag(a))
|
||||
d := math.Sqrt(r * r + i * i)
|
||||
return ComplexAbs[T](complex(d, 0))
|
||||
}
|
||||
|
||||
func OrderedAbsDifference[T OrderedNumeric](a, b T) T {
|
||||
return T(AbsDifference(OrderedAbs[T](a), OrderedAbs[T](b)))
|
||||
}
|
||||
|
||||
func ComplexAbsDifference[T Complex](a, b T) T {
|
||||
return T(AbsDifference(ComplexAbs[T](a), ComplexAbs[T](b)))
|
||||
}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// // OrderedAbs is a helper type that defines an Abs method for
|
||||
// // ordered numeric types.
|
||||
// type OrderedAbs[T OrderedNumeric] T
|
||||
//
|
||||
// func (a OrderedAbs[T]) Abs() OrderedAbs[T] {
|
||||
// if a < 0 {
|
||||
// return -a
|
||||
// }
|
||||
// return a
|
||||
// }
|
||||
//
|
||||
// // ComplexAbs is a helper type that defines an Abs method for
|
||||
// // complex types.
|
||||
// type ComplexAbs[T Complex] T
|
||||
//
|
||||
// func (a ComplexAbs[T]) Abs() ComplexAbs[T] {
|
||||
// r := float64(real(a))
|
||||
// i := float64(imag(a))
|
||||
// d := math.Sqrt(r * r + i * i)
|
||||
// return ComplexAbs[T](complex(d, 0))
|
||||
// }
|
||||
//
|
||||
// func OrderedAbsDifference[T OrderedNumeric](a, b T) T {
|
||||
// return T(AbsDifference(OrderedAbs[T](a), OrderedAbs[T](b)))
|
||||
// }
|
||||
//
|
||||
// func ComplexAbsDifference[T Complex](a, b T) T {
|
||||
// return T(AbsDifference(ComplexAbs[T](a), ComplexAbs[T](b)))
|
||||
// }
|
||||
|
@ -8,7 +8,8 @@ type myInt int
|
||||
|
||||
// Parameterized type declarations
|
||||
|
||||
type T1[P any] P
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
type T1[P any] P // ERROR cannot use a type parameter as RHS in type declaration
|
||||
|
||||
type T2[P any] struct {
|
||||
f P
|
||||
@ -19,7 +20,7 @@ type List[P any] []P
|
||||
|
||||
// Alias type declarations cannot have type parameters.
|
||||
// Issue #46477 proposses to change that.
|
||||
type A1[P any] = /* ERROR cannot be alias */ P
|
||||
type A1[P any] = /* ERROR cannot be alias */ struct{}
|
||||
|
||||
// Pending clarification of #46477 we disallow aliases
|
||||
// of generic types.
|
||||
|
@ -87,25 +87,27 @@ type NumericAbs[T any] interface {
|
||||
|
||||
func AbsDifference[T NumericAbs[T]](x T) { panic(0) }
|
||||
|
||||
type OrderedAbs[T any] T
|
||||
|
||||
func (a OrderedAbs[T]) Abs() OrderedAbs[T]
|
||||
|
||||
func OrderedAbsDifference[T any](x T) {
|
||||
AbsDifference(OrderedAbs[T](x))
|
||||
}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// type OrderedAbs[T any] T
|
||||
//
|
||||
// func (a OrderedAbs[T]) Abs() OrderedAbs[T]
|
||||
//
|
||||
// func OrderedAbsDifference[T any](x T) {
|
||||
// AbsDifference(OrderedAbs[T](x))
|
||||
// }
|
||||
|
||||
// same code, reduced to essence
|
||||
|
||||
func g[P interface{ m() P }](x P) { panic(0) }
|
||||
|
||||
type T4[P any] P
|
||||
|
||||
func (_ T4[P]) m() T4[P]
|
||||
|
||||
func _[Q any](x Q) {
|
||||
g(T4[Q](x))
|
||||
}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// type T4[P any] P
|
||||
//
|
||||
// func (_ T4[P]) m() T4[P]
|
||||
//
|
||||
// func _[Q any](x Q) {
|
||||
// g(T4[Q](x))
|
||||
// }
|
||||
|
||||
// Another test case that caused problems in the past
|
||||
|
||||
|
@ -353,15 +353,16 @@ func _() {
|
||||
|
||||
// the previous example was extracted from
|
||||
|
||||
func f12[T interface{m() T}]() {}
|
||||
|
||||
type A[T any] T
|
||||
|
||||
func (a A[T]) m() A[T]
|
||||
|
||||
func _[T any]() {
|
||||
f12[A[T]]()
|
||||
}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// func f12[T interface{m() T}]() {}
|
||||
//
|
||||
// type A[T any] T
|
||||
//
|
||||
// func (a A[T]) m() A[T]
|
||||
//
|
||||
// func _[T any]() {
|
||||
// f12[A[T]]()
|
||||
// }
|
||||
|
||||
// method expressions
|
||||
|
||||
|
@ -6,8 +6,6 @@
|
||||
|
||||
package p
|
||||
|
||||
import "unsafe"
|
||||
|
||||
// Parameterized types may have methods.
|
||||
type T1[A any] struct{ a A }
|
||||
|
||||
@ -97,17 +95,18 @@ type T0 struct{}
|
||||
func (T0) _() {}
|
||||
func (T1[A]) _() {}
|
||||
|
||||
// A generic receiver type may constrain its type parameter such
|
||||
// that it must be a pointer type. Such receiver types are not
|
||||
// permitted.
|
||||
type T3a[P interface{ ~int | ~string | ~float64 }] P
|
||||
|
||||
func (T3a[_]) m() {} // this is ok
|
||||
|
||||
type T3b[P interface{ ~unsafe.Pointer }] P
|
||||
|
||||
func (T3b /* ERROR invalid receiver */ [_]) m() {}
|
||||
|
||||
type T3c[P interface{ *int | *string }] P
|
||||
|
||||
func (T3c /* ERROR invalid receiver */ [_]) m() {}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// // A generic receiver type may constrain its type parameter such
|
||||
// // that it must be a pointer type. Such receiver types are not
|
||||
// // permitted.
|
||||
// type T3a[P interface{ ~int | ~string | ~float64 }] P
|
||||
//
|
||||
// func (T3a[_]) m() {} // this is ok
|
||||
//
|
||||
// type T3b[P interface{ ~unsafe.Pointer }] P
|
||||
//
|
||||
// func (T3b /* ERROR invalid receiver */ [_]) m() {}
|
||||
//
|
||||
// type T3c[P interface{ *int | *string }] P
|
||||
//
|
||||
// func (T3c /* ERROR invalid receiver */ [_]) m() {}
|
||||
|
@ -185,12 +185,13 @@ type _ struct {
|
||||
// _ = y < 0
|
||||
// }
|
||||
|
||||
// It is not permitted to declare a local type whose underlying
|
||||
// type is a type parameter not declared by that type declaration.
|
||||
func _[T any]() {
|
||||
type _ T // ERROR cannot use function type parameter T as RHS in type declaration
|
||||
type _ [_ any] T // ERROR cannot use function type parameter T as RHS in type declaration
|
||||
}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// // It is not permitted to declare a local type whose underlying
|
||||
// // type is a type parameter not declared by that type declaration.
|
||||
// func _[T any]() {
|
||||
// type _ T // ERROR cannot use function type parameter T as RHS in type declaration
|
||||
// type _ [_ any] T // ERROR cannot use function type parameter T as RHS in type declaration
|
||||
// }
|
||||
|
||||
// As a special case, an explicit type argument may be omitted
|
||||
// from a type parameter bound if the type bound expects exactly
|
||||
|
@ -74,9 +74,10 @@ func F20[t Z20]() { F20(t /* ERROR invalid composite literal type */ {}) }
|
||||
type Z21 /* ERROR illegal cycle */ interface{ Z21 }
|
||||
func F21[T Z21]() { ( /* ERROR not used */ F21[Z21]) }
|
||||
|
||||
// crash 24
|
||||
type T24[P any] P
|
||||
func (r T24[P]) m() { T24 /* ERROR without instantiation */ .m() }
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// // crash 24
|
||||
// type T24[P any] P
|
||||
// func (r T24[P]) m() { T24 /* ERROR without instantiation */ .m() }
|
||||
|
||||
// crash 25
|
||||
type T25[A any] int
|
||||
|
@ -4,14 +4,15 @@
|
||||
|
||||
package p
|
||||
|
||||
type T[P any] P
|
||||
type A = T // ERROR cannot use generic type
|
||||
var x A[int]
|
||||
var _ A
|
||||
|
||||
type B = T[int]
|
||||
var y B = x
|
||||
var _ B /* ERROR not a generic type */ [int]
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// type T[P any] P
|
||||
// type A = T // ERROR cannot use generic type
|
||||
// var x A[int]
|
||||
// var _ A
|
||||
//
|
||||
// type B = T[int]
|
||||
// var y B = x
|
||||
// var _ B /* ERROR not a generic type */ [int]
|
||||
|
||||
// test case from issue
|
||||
|
||||
|
@ -8,7 +8,7 @@
|
||||
|
||||
package p
|
||||
|
||||
type E0[P any] P
|
||||
type E0[P any] []P
|
||||
type E1[P any] *P
|
||||
type E2[P any] struct{ _ P }
|
||||
type E3[P any] struct{ _ *P }
|
||||
|
@ -4,9 +4,10 @@
|
||||
|
||||
package P
|
||||
|
||||
// It is not permitted to declare a local type whose underlying
|
||||
// type is a type parameters not declared by that type declaration.
|
||||
func _[T any]() {
|
||||
type _ T // ERROR cannot use function type parameter T as RHS in type declaration
|
||||
type _ [_ any] T // ERROR cannot use function type parameter T as RHS in type declaration
|
||||
}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// // It is not permitted to declare a local type whose underlying
|
||||
// // type is a type parameters not declared by that type declaration.
|
||||
// func _[T any]() {
|
||||
// type _ T // ERROR cannot use function type parameter T as RHS in type declaration
|
||||
// type _ [_ any] T // ERROR cannot use function type parameter T as RHS in type declaration
|
||||
// }
|
||||
|
@ -4,15 +4,16 @@
|
||||
|
||||
package p
|
||||
|
||||
type T1[P any] P
|
||||
|
||||
func (T1[_]) m() {}
|
||||
|
||||
func _[P any](x *T1[P]) {
|
||||
// x.m exists because x is of type *T1 where T1 is a defined type
|
||||
// (even though under(T1) is a type parameter)
|
||||
x.m()
|
||||
}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// type T1[P any] P
|
||||
//
|
||||
// func (T1[_]) m() {}
|
||||
//
|
||||
// func _[P any](x *T1[P]) {
|
||||
// // x.m exists because x is of type *T1 where T1 is a defined type
|
||||
// // (even though under(T1) is a type parameter)
|
||||
// x.m()
|
||||
// }
|
||||
|
||||
|
||||
func _[P interface{ m() }](x P) {
|
||||
@ -40,29 +41,31 @@ type Barer[t any] interface {
|
||||
Bar(t)
|
||||
}
|
||||
|
||||
type Foo1[t any] t
|
||||
type Bar[t any] t
|
||||
|
||||
func (l Foo1[t]) Foo(v Barer[t]) { v.Bar(t(l)) }
|
||||
func (b *Bar[t]) Bar(l t) { *b = Bar[t](l) }
|
||||
|
||||
func _[t any](f Fooer1[t]) t {
|
||||
var b Bar[t]
|
||||
f.Foo(&b)
|
||||
return t(b)
|
||||
}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// type Foo1[t any] t
|
||||
// type Bar[t any] t
|
||||
//
|
||||
// func (l Foo1[t]) Foo(v Barer[t]) { v.Bar(t(l)) }
|
||||
// func (b *Bar[t]) Bar(l t) { *b = Bar[t](l) }
|
||||
//
|
||||
// func _[t any](f Fooer1[t]) t {
|
||||
// var b Bar[t]
|
||||
// f.Foo(&b)
|
||||
// return t(b)
|
||||
// }
|
||||
|
||||
// Test case 2 from issue
|
||||
|
||||
type Fooer2[t any] interface {
|
||||
Foo()
|
||||
}
|
||||
|
||||
type Foo2[t any] t
|
||||
|
||||
func (f *Foo2[t]) Foo() {}
|
||||
|
||||
func _[t any](v t) {
|
||||
var f = Foo2[t](v)
|
||||
_ = Fooer2[t](&f)
|
||||
}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// type Fooer2[t any] interface {
|
||||
// Foo()
|
||||
// }
|
||||
//
|
||||
// type Foo2[t any] t
|
||||
//
|
||||
// func (f *Foo2[t]) Foo() {}
|
||||
//
|
||||
// func _[t any](v t) {
|
||||
// var f = Foo2[t](v)
|
||||
// _ = Fooer2[t](&f)
|
||||
// }
|
||||
|
@ -6,11 +6,6 @@
|
||||
|
||||
package main
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
"math"
|
||||
)
|
||||
|
||||
type Numeric interface {
|
||||
~int | ~int8 | ~int16 | ~int32 | ~int64 |
|
||||
~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
|
||||
@ -43,55 +38,57 @@ type Complex interface {
|
||||
~complex64 | ~complex128
|
||||
}
|
||||
|
||||
// orderedAbs is a helper type that defines an Abs method for
|
||||
// ordered numeric types.
|
||||
type orderedAbs[T orderedNumeric] T
|
||||
|
||||
func (a orderedAbs[T]) Abs() orderedAbs[T] {
|
||||
if a < 0 {
|
||||
return -a
|
||||
}
|
||||
return a
|
||||
}
|
||||
|
||||
// complexAbs is a helper type that defines an Abs method for
|
||||
// complex types.
|
||||
type complexAbs[T Complex] T
|
||||
|
||||
func (a complexAbs[T]) Abs() complexAbs[T] {
|
||||
r := float64(real(a))
|
||||
i := float64(imag(a))
|
||||
d := math.Sqrt(r*r + i*i)
|
||||
return complexAbs[T](complex(d, 0))
|
||||
}
|
||||
|
||||
// OrderedAbsDifference returns the absolute value of the difference
|
||||
// between a and b, where a and b are of an ordered type.
|
||||
func orderedAbsDifference[T orderedNumeric](a, b T) T {
|
||||
return T(absDifference(orderedAbs[T](a), orderedAbs[T](b)))
|
||||
}
|
||||
|
||||
// ComplexAbsDifference returns the absolute value of the difference
|
||||
// between a and b, where a and b are of a complex type.
|
||||
func complexAbsDifference[T Complex](a, b T) T {
|
||||
return T(absDifference(complexAbs[T](a), complexAbs[T](b)))
|
||||
}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// // orderedAbs is a helper type that defines an Abs method for
|
||||
// // ordered numeric types.
|
||||
// type orderedAbs[T orderedNumeric] T
|
||||
//
|
||||
// func (a orderedAbs[T]) Abs() orderedAbs[T] {
|
||||
// if a < 0 {
|
||||
// return -a
|
||||
// }
|
||||
// return a
|
||||
// }
|
||||
//
|
||||
// // complexAbs is a helper type that defines an Abs method for
|
||||
// // complex types.
|
||||
// type complexAbs[T Complex] T
|
||||
//
|
||||
// func (a complexAbs[T]) Abs() complexAbs[T] {
|
||||
// r := float64(real(a))
|
||||
// i := float64(imag(a))
|
||||
// d := math.Sqrt(r*r + i*i)
|
||||
// return complexAbs[T](complex(d, 0))
|
||||
// }
|
||||
//
|
||||
// // OrderedAbsDifference returns the absolute value of the difference
|
||||
// // between a and b, where a and b are of an ordered type.
|
||||
// func orderedAbsDifference[T orderedNumeric](a, b T) T {
|
||||
// return T(absDifference(orderedAbs[T](a), orderedAbs[T](b)))
|
||||
// }
|
||||
//
|
||||
// // ComplexAbsDifference returns the absolute value of the difference
|
||||
// // between a and b, where a and b are of a complex type.
|
||||
// func complexAbsDifference[T Complex](a, b T) T {
|
||||
// return T(absDifference(complexAbs[T](a), complexAbs[T](b)))
|
||||
// }
|
||||
|
||||
func main() {
|
||||
if got, want := orderedAbsDifference(1.0, -2.0), 3.0; got != want {
|
||||
panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
}
|
||||
if got, want := orderedAbsDifference(-1.0, 2.0), 3.0; got != want {
|
||||
panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
}
|
||||
if got, want := orderedAbsDifference(-20, 15), 35; got != want {
|
||||
panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
}
|
||||
|
||||
if got, want := complexAbsDifference(5.0+2.0i, 2.0-2.0i), 5+0i; got != want {
|
||||
panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
}
|
||||
if got, want := complexAbsDifference(2.0-2.0i, 5.0+2.0i), 5+0i; got != want {
|
||||
panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
}
|
||||
// // For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// if got, want := orderedAbsDifference(1.0, -2.0), 3.0; got != want {
|
||||
// panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
// }
|
||||
// if got, want := orderedAbsDifference(-1.0, 2.0), 3.0; got != want {
|
||||
// panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
// }
|
||||
// if got, want := orderedAbsDifference(-20, 15), 35; got != want {
|
||||
// panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
// }
|
||||
//
|
||||
// if got, want := complexAbsDifference(5.0+2.0i, 2.0-2.0i), 5+0i; got != want {
|
||||
// panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
// }
|
||||
// if got, want := complexAbsDifference(2.0-2.0i, 5.0+2.0i), 5+0i; got != want {
|
||||
// panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
// }
|
||||
}
|
||||
|
@ -4,10 +4,6 @@
|
||||
|
||||
package a
|
||||
|
||||
import (
|
||||
"math"
|
||||
)
|
||||
|
||||
type Numeric interface {
|
||||
~int | ~int8 | ~int16 | ~int32 | ~int64 |
|
||||
~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
|
||||
@ -40,36 +36,37 @@ type Complex interface {
|
||||
~complex64 | ~complex128
|
||||
}
|
||||
|
||||
// orderedAbs is a helper type that defines an Abs method for
|
||||
// ordered numeric types.
|
||||
type orderedAbs[T orderedNumeric] T
|
||||
|
||||
func (a orderedAbs[T]) Abs() orderedAbs[T] {
|
||||
if a < 0 {
|
||||
return -a
|
||||
}
|
||||
return a
|
||||
}
|
||||
|
||||
// complexAbs is a helper type that defines an Abs method for
|
||||
// complex types.
|
||||
type complexAbs[T Complex] T
|
||||
|
||||
func (a complexAbs[T]) Abs() complexAbs[T] {
|
||||
r := float64(real(a))
|
||||
i := float64(imag(a))
|
||||
d := math.Sqrt(r*r + i*i)
|
||||
return complexAbs[T](complex(d, 0))
|
||||
}
|
||||
|
||||
// OrderedAbsDifference returns the absolute value of the difference
|
||||
// between a and b, where a and b are of an ordered type.
|
||||
func OrderedAbsDifference[T orderedNumeric](a, b T) T {
|
||||
return T(absDifference(orderedAbs[T](a), orderedAbs[T](b)))
|
||||
}
|
||||
|
||||
// ComplexAbsDifference returns the absolute value of the difference
|
||||
// between a and b, where a and b are of a complex type.
|
||||
func ComplexAbsDifference[T Complex](a, b T) T {
|
||||
return T(absDifference(complexAbs[T](a), complexAbs[T](b)))
|
||||
}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// // orderedAbs is a helper type that defines an Abs method for
|
||||
// // ordered numeric types.
|
||||
// type orderedAbs[T orderedNumeric] T
|
||||
//
|
||||
// func (a orderedAbs[T]) Abs() orderedAbs[T] {
|
||||
// if a < 0 {
|
||||
// return -a
|
||||
// }
|
||||
// return a
|
||||
// }
|
||||
//
|
||||
// // complexAbs is a helper type that defines an Abs method for
|
||||
// // complex types.
|
||||
// type complexAbs[T Complex] T
|
||||
//
|
||||
// func (a complexAbs[T]) Abs() complexAbs[T] {
|
||||
// r := float64(real(a))
|
||||
// i := float64(imag(a))
|
||||
// d := math.Sqrt(r*r + i*i)
|
||||
// return complexAbs[T](complex(d, 0))
|
||||
// }
|
||||
//
|
||||
// // OrderedAbsDifference returns the absolute value of the difference
|
||||
// // between a and b, where a and b are of an ordered type.
|
||||
// func OrderedAbsDifference[T orderedNumeric](a, b T) T {
|
||||
// return T(absDifference(orderedAbs[T](a), orderedAbs[T](b)))
|
||||
// }
|
||||
//
|
||||
// // ComplexAbsDifference returns the absolute value of the difference
|
||||
// // between a and b, where a and b are of a complex type.
|
||||
// func ComplexAbsDifference[T Complex](a, b T) T {
|
||||
// return T(absDifference(complexAbs[T](a), complexAbs[T](b)))
|
||||
// }
|
||||
|
@ -4,26 +4,22 @@
|
||||
|
||||
package main
|
||||
|
||||
import (
|
||||
"a"
|
||||
"fmt"
|
||||
)
|
||||
|
||||
func main() {
|
||||
if got, want := a.OrderedAbsDifference(1.0, -2.0), 3.0; got != want {
|
||||
panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
}
|
||||
if got, want := a.OrderedAbsDifference(-1.0, 2.0), 3.0; got != want {
|
||||
panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
}
|
||||
if got, want := a.OrderedAbsDifference(-20, 15), 35; got != want {
|
||||
panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
}
|
||||
|
||||
if got, want := a.ComplexAbsDifference(5.0+2.0i, 2.0-2.0i), 5+0i; got != want {
|
||||
panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
}
|
||||
if got, want := a.ComplexAbsDifference(2.0-2.0i, 5.0+2.0i), 5+0i; got != want {
|
||||
panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// if got, want := a.OrderedAbsDifference(1.0, -2.0), 3.0; got != want {
|
||||
// panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
// }
|
||||
// if got, want := a.OrderedAbsDifference(-1.0, 2.0), 3.0; got != want {
|
||||
// panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
// }
|
||||
// if got, want := a.OrderedAbsDifference(-20, 15), 35; got != want {
|
||||
// panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
// }
|
||||
//
|
||||
// if got, want := a.ComplexAbsDifference(5.0+2.0i, 2.0-2.0i), 5+0i; got != want {
|
||||
// panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
// }
|
||||
// if got, want := a.ComplexAbsDifference(2.0-2.0i, 5.0+2.0i), 5+0i; got != want {
|
||||
// panic(fmt.Sprintf("got = %v, want = %v", got, want))
|
||||
// }
|
||||
}
|
||||
|
@ -59,12 +59,13 @@ type Ints interface {
|
||||
~int32 | ~int
|
||||
}
|
||||
|
||||
type StringInt[T Ints] T
|
||||
|
||||
//go:noinline
|
||||
func (m StringInt[T]) String() string {
|
||||
return strconv.Itoa(int(m))
|
||||
}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// type StringInt[T Ints] T
|
||||
//
|
||||
// //go:noinline
|
||||
// func (m StringInt[T]) String() string {
|
||||
// return strconv.Itoa(int(m))
|
||||
// }
|
||||
|
||||
type StringStruct[T Ints] struct {
|
||||
f T
|
||||
@ -84,22 +85,23 @@ func main() {
|
||||
panic(fmt.Sprintf("got %s, want %s", got, want))
|
||||
}
|
||||
|
||||
x2 := []StringInt[myint]{StringInt[myint](5), StringInt[myint](7), StringInt[myint](6)}
|
||||
|
||||
// stringify on an instantiated type, whose bound method is associated with
|
||||
// the generic type StringInt[T], which maps directly to T.
|
||||
got2 := stringify(x2)
|
||||
want2 := []string{ "5", "7", "6" }
|
||||
if !reflect.DeepEqual(got2, want2) {
|
||||
panic(fmt.Sprintf("got %s, want %s", got2, want2))
|
||||
}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// x2 := []StringInt[myint]{StringInt[myint](5), StringInt[myint](7), StringInt[myint](6)}
|
||||
//
|
||||
// // stringify on an instantiated type, whose bound method is associated with
|
||||
// // the generic type StringInt[T], which maps directly to T.
|
||||
// got2 := stringify(x2)
|
||||
// want2 := []string{"5", "7", "6"}
|
||||
// if !reflect.DeepEqual(got2, want2) {
|
||||
// panic(fmt.Sprintf("got %s, want %s", got2, want2))
|
||||
// }
|
||||
|
||||
// stringify on an instantiated type, whose bound method is associated with
|
||||
// the generic type StringStruct[T], which maps to a struct containing T.
|
||||
x3 := []StringStruct[myint]{StringStruct[myint]{f: 11}, StringStruct[myint]{f: 10}, StringStruct[myint]{f: 9}}
|
||||
|
||||
got3 := stringify(x3)
|
||||
want3 := []string{ "11", "10", "9" }
|
||||
want3 := []string{"11", "10", "9"}
|
||||
if !reflect.DeepEqual(got3, want3) {
|
||||
panic(fmt.Sprintf("got %s, want %s", got3, want3))
|
||||
}
|
||||
|
@ -6,35 +6,32 @@
|
||||
|
||||
package main
|
||||
|
||||
import (
|
||||
"fmt"
|
||||
)
|
||||
|
||||
type FooType[T any] interface {
|
||||
Foo(BarType[T])string
|
||||
Foo(BarType[T]) string
|
||||
}
|
||||
type BarType[T any] interface {
|
||||
Bar(FooType[T])string
|
||||
}
|
||||
|
||||
type Baz[T any] T
|
||||
func (l Baz[T]) Foo(v BarType[T]) string {
|
||||
return v.Bar(l)
|
||||
}
|
||||
type Bob[T any] T
|
||||
func (l Bob[T]) Bar(v FooType[T]) string {
|
||||
if v,ok := v.(Baz[T]);ok{
|
||||
return fmt.Sprintf("%v%v",v,l)
|
||||
}
|
||||
return ""
|
||||
Bar(FooType[T]) string
|
||||
}
|
||||
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// type Baz[T any] T
|
||||
// func (l Baz[T]) Foo(v BarType[T]) string {
|
||||
// return v.Bar(l)
|
||||
// }
|
||||
// type Bob[T any] T
|
||||
// func (l Bob[T]) Bar(v FooType[T]) string {
|
||||
// if v,ok := v.(Baz[T]);ok{
|
||||
// return fmt.Sprintf("%v%v",v,l)
|
||||
// }
|
||||
// return ""
|
||||
// }
|
||||
|
||||
func main() {
|
||||
var baz Baz[int] = 123
|
||||
var bob Bob[int] = 456
|
||||
|
||||
if got, want := baz.Foo(bob), "123456"; got != want {
|
||||
panic(fmt.Sprintf("got %s want %s", got, want))
|
||||
}
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// var baz Baz[int] = 123
|
||||
// var bob Bob[int] = 456
|
||||
//
|
||||
// if got, want := baz.Foo(bob), "123456"; got != want {
|
||||
// panic(fmt.Sprintf("got %s want %s", got, want))
|
||||
// }
|
||||
}
|
||||
|
@ -12,10 +12,11 @@ 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)) }
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// 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]
|
||||
@ -26,12 +27,14 @@ 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)}
|
||||
)
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// 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)
|
||||
// For now, a lone type parameter is not permitted as RHS in a type declaration (issue #45639).
|
||||
// fmt.Printf("%v\n", e0)
|
||||
// fmt.Printf("%v\n", e1)
|
||||
}
|
||||
|
@ -1,2 +0,0 @@
|
||||
(eq (lit 128) (lit 64))
|
||||
(eq (lit true) (lit true))
|
Loading…
Reference in New Issue
Block a user