src/cmd/compile/internal/syntax/testdata/typeset.go

// 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.

// This file contains test cases for typeset-only constraint elements.

package p

type (
        _[_ t] t
        _[_ ~t] t
        _[_ t|t] t
        _[_ ~t|t] t
        _[_ t|~t] t
        _[_ ~t|~t] t

        _[_ t, _, _ t|t] t
        _[_ t, _, _ ~t|t] t
        _[_ t, _, _ t|~t] t
        _[_ t, _, _ ~t|~t] t

        _[_ t.t] t
        _[_ ~t.t] t
        _[_ t.t|t.t] t
        _[_ ~t.t|t.t] t
        _[_ t.t|~t.t] t
        _[_ ~t.t|~t.t] t

        _[_ t, _, _ t.t|t.t] t
        _[_ t, _, _ ~t.t|t.t] t
        _[_ t, _, _ t.t|~t.t] t
        _[_ t, _, _ ~t.t|~t.t] t

        _[_ struct{}] t
        _[_ ~struct{}] t

        _[_ struct{}|t] t
        _[_ ~struct{}|t] t
        _[_ struct{}|~t] t
        _[_ ~struct{}|~t] t

        _[_ t|struct{}] t
        _[_ ~t|struct{}] t
        _[_ t|~struct{}] t
        _[_ ~t|~struct{}] t

        // test cases for go.dev/issue/49175
        _[_ []t]t
        _[_ [1]t]t
        _[_ ~[]t]t
        _[_ ~[1]t]t
        t [ /* ERROR missing type parameter name */ t[0]]t
)

// test cases for go.dev/issue/49174
func _[_ t]() {}
func _[_ []t]() {}
func _[_ [1]t]() {}
func _[_ []t | t]() {}
func _[_ [1]t | t]() {}
func _[_ t | []t]() {}
func _[_ []t | []t]() {}
func _[_ [1]t | [1]t]() {}
func _[_ t[t] | t[t]]() {}

// Single-expression type parameter lists and those that don't start
// with a (type parameter) name are considered array sizes.
// The term must be a valid expression (it could be a type incl. a
// tilde term) but the type-checker will complain.
type (
        _[t] t
        _[t|t] t

        // These are invalid and the type-checker will complain.
        _[~t] t
        _[~t|t] t
        _[t|~t] t
        _[~t|~t] t
)

type (
        _[_ t, t /* ERROR missing type constraint */ ] t
        _[_ ~t, t /* ERROR missing type constraint */ ] t
        _[_ t, /* ERROR missing type parameter name */ ~t] t
        _[_ ~t, /* ERROR missing type parameter name */ ~t] t

        _[_ t|t, /* ERROR missing type parameter name */ t|t] t
        _[_ ~t|t, /* ERROR missing type parameter name */ t|t] t
        _[_ t|t, /* ERROR missing type parameter name */ ~t|t] t
        _[_ ~t|t, /* ERROR missing type parameter name */ ~t|t] t
)