go/types, types2: use "multiple-value" instead "n-valued" in error messages

This matches current compiler behavior.

For #55326.

Change-Id: I9ebe2914323072b5454fb9af2d15c9dd2d711bad
Reviewed-on: https://go-review.googlesource.com/c/go/+/434735
Run-TryBot: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>

src/cmd/compile/internal/types2/expr.go

@@ -1860,11 +1860,7 @@ func (check *Checker) singleValue(x *operand) {
 		// tuple types are never named - no need for underlying type below
 		if t, ok := x.typ.(*Tuple); ok {
 			assert(t.Len() != 1)
-			if check.conf.CompilerErrorMessages {
-				check.errorf(x, _TooManyValues, "multiple-value %s in single-value context", x)
-			} else {
-				check.errorf(x, _TooManyValues, "%d-valued %s where single value is expected", t.Len(), x)
-			}
+			check.errorf(x, _TooManyValues, "multiple-value %s in single-value context", x)
 			x.mode = invalid
 		}
 	}

src/go/types/expr.go

@@ -1803,11 +1803,7 @@ func (check *Checker) singleValue(x *operand) {
 		// tuple types are never named - no need for underlying type below
 		if t, ok := x.typ.(*Tuple); ok {
 			assert(t.Len() != 1)
-			if compilerErrorMessages {
-				check.errorf(x, _TooManyValues, "multiple-value %s in single-value context", x)
-			} else {
-				check.errorf(x, _TooManyValues, "%d-valued %s where single value is expected", t.Len(), x)
-			}
+			check.errorf(x, _TooManyValues, "multiple-value %s in single-value context", x)
 			x.mode = invalid
 		}
 	}

src/internal/types/testdata/check/expr0.go

@@ -175,8 +175,8 @@ var (
 func g() (a, b int) { return }
 
 func _() {
-	_ = -g /* ERROR 2-valued g */ ()
-	_ = <-g /* ERROR 2-valued g */ ()
+	_ = -g /* ERROR multiple-value g */ ()
+	_ = <-g /* ERROR multiple-value g */ ()
 }
 
 // ~ is accepted as unary operator only permitted in interface type elements

src/internal/types/testdata/check/expr1.go

@@ -120,8 +120,8 @@ func _(x, y string, z mystring) {
 func f() (a, b int) { return }
 
 func _(x int) {
-	_ = f /* ERROR 2-valued f */ () + 1
-	_ = x + f /* ERROR 2-valued f */ ()
-	_ = f /* ERROR 2-valued f */ () + f
-	_ = f /* ERROR 2-valued f */ () + f /* ERROR 2-valued f */ ()
+	_ = f /* ERROR multiple-value f */ () + 1
+	_ = x + f /* ERROR multiple-value f */ ()
+	_ = f /* ERROR multiple-value f */ () + f
+	_ = f /* ERROR multiple-value f */ () + f /* ERROR multiple-value f */ ()
 }

src/internal/types/testdata/check/expr3.go

@@ -554,7 +554,7 @@ func _calls() {
 	fi(1, 2.0, x, 3.14, "foo")
 	fi(g2())
 	fi(0, g2)
-	fi(0, g2 /* ERROR "2-valued g2" */ ())
+	fi(0, g2 /* ERROR "multiple-value g2" */ ())
 }
 
 func issue6344() {

src/internal/types/testdata/check/issues0.go

@@ -61,10 +61,10 @@ func issue9473(a []int, b ...int) {
 	_ = append(f1())
 	_ = append(f2 /* ERROR cannot use .* in argument */ ())
 	_ = append(f2()... /* ERROR cannot use ... */ )
-	_ = append(f0(), f1 /* ERROR 2-valued f1 */ ())
-	_ = append(f0(), f2 /* ERROR 2-valued f2 */ ())
-	_ = append(f0(), f1 /* ERROR 2-valued f1 */ ()...)
-	_ = append(f0(), f2 /* ERROR 2-valued f2 */ ()...)
+	_ = append(f0(), f1 /* ERROR multiple-value f1 */ ())
+	_ = append(f0(), f2 /* ERROR multiple-value f2 */ ())
+	_ = append(f0(), f1 /* ERROR multiple-value f1 */ ()...)
+	_ = append(f0(), f2 /* ERROR multiple-value f2 */ ()...)
 
 	// variadic user-defined function
 	append_(f0())
@@ -72,10 +72,10 @@ func issue9473(a []int, b ...int) {
 	append_(f1())
 	append_(f2 /* ERROR cannot use .* in argument */ ())
 	append_(f2()... /* ERROR cannot use ... */ )
-	append_(f0(), f1 /* ERROR 2-valued f1 */ ())
-	append_(f0(), f2 /* ERROR 2-valued f2 */ ())
-	append_(f0(), f1 /* ERROR 2-valued f1 */ ()...)
-	append_(f0(), f2 /* ERROR 2-valued f2 */ ()...)
+	append_(f0(), f1 /* ERROR multiple-value f1 */ ())
+	append_(f0(), f2 /* ERROR multiple-value f2 */ ())
+	append_(f0(), f1 /* ERROR multiple-value f1 */ ()...)
+	append_(f0(), f2 /* ERROR multiple-value f2 */ ()...)
 }
 
 // Check that embedding a non-interface type in an interface results in a good error message.

src/internal/types/testdata/check/stmt0.go

@@ -650,14 +650,14 @@ func issue11667() {
 
 func issue11687() {
 	f := func() (_, _ int) { return }
-	switch f /* ERROR "2-valued f" */ () {
+	switch f /* ERROR "multiple-value f" */ () {
 	}
 	var x int
-	switch f /* ERROR "2-valued f" */ () {
+	switch f /* ERROR "multiple-value f" */ () {
 	case x:
 	}
 	switch x {
-	case f /* ERROR "2-valued f" */ ():
+	case f /* ERROR "multiple-value f" */ ():
 	}
 }
 

src/internal/types/testdata/check/typeparams.go

@@ -39,7 +39,7 @@ var _ = f(0 /* ERROR cannot use 0 .* as \[\]chan int */ )
 
 func swap[A, B any](a A, b B) (B, A) { return b, a }
 
-var _ = swap /* ERROR single value is expected */ [int, float32](1, 2)
+var _ = swap /* ERROR multiple-value */ [int, float32](1, 2)
 var f32, i = swap[int, float32](swap[float32, int](1, 2))
 var _ float32 = f32
 var _ int = i

src/internal/types/testdata/check/vardecl.go

@@ -28,7 +28,7 @@ var _ = 1, 2 /* ERROR "extra init expr 2" */
 var _, _ = 1 /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */
 var _, _, _ /* ERROR "missing init expr for _" */ = 1, 2
 
-var _ = g /* ERROR "2-valued g" */ ()
+var _ = g /* ERROR "multiple-value g" */ ()
 var _, _ = g()
 var _, _, _ = g /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */ ()
 
@@ -47,7 +47,7 @@ var (
 	_, _ = 1 /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */
 	_, _, _ /* ERROR "missing init expr for _" */ = 1, 2
 
-	_ = g /* ERROR "2-valued g" */ ()
+	_ = g /* ERROR "multiple-value g" */ ()
 	_, _ = g()
 	_, _, _ = g /* ERROR "cannot initialize [0-9]+ variables with [0-9]+ values" */ ()