[dev.typeparams] cmd/compile/internal/syntax: type parameters must always be named

Report an error otherwise.

Change-Id: Ia76ea03a3f26b13dd9bca49f7bd42101d1ff1f9e
Reviewed-on: https://go-review.googlesource.com/c/go/+/278475
Trust: Robert Griesemer <gri@golang.org>
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/src/cmd/compile/internal/syntax/testdata/tparams.go2 b/src/cmd/compile/internal/syntax/testdata/tparams.go2
new file mode 100644
index 0000000000..42031c3277
--- /dev/null
+++ b/src/cmd/compile/internal/syntax/testdata/tparams.go2
@@ -0,0 +1,22 @@
+// Copyright 2020 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 p
+
+type t[ /* ERROR type parameters must be named */ a, b] struct{}
+type t[a t, b t, /* ERROR type parameters must be named */ c] struct{}
+type t struct {
+	t [n]byte
+	t[a]
+	t[a, b]
+}
+type t interface {
+	t[a]
+	m /* ERROR method cannot have type parameters */ [_ _, /* ERROR mixed */ _]()
+	t[a, b]
+}
+
+func f[ /* ERROR empty type parameter list */ ]()
+func f[ /* ERROR type parameters must be named */ a, b]()
+func f[a t, b t, /* ERROR type parameters must be named */ c]()