i = p.badExpr()
				} else {
					i, comma = p.typeList(false)
				}
				if comma || p.tok == _Rbrack {
					p.want(_Rbrack)
					// x[], x[i,] or x[i, j, ...]
					t := new(IndexExpr)
					t.pos = pos
					t.X = x
					t.Index = i
					x = t
					break
				}
			}

			// x[i:...

		return e
	case *ast.StarExpr:
		// *T is valid, but **T is not
		if _, ok := e.X.(*ast.StarExpr); !ok {
			return embeddedFieldIdent(e.X)
		}
	case *ast.SelectorExpr:
		return e.Sel
	case *ast.IndexExpr:
		return embeddedFieldIdent(e.X)
	case *ast.IndexListExpr:
		return embeddedFieldIdent(e.X)
	}
	return nil // invalid embedded field
}

	case *CompositeLit:
		if n.Type != nil {
			Walk(v, n.Type)
		}
		walkList(v, n.Elts)

	case *ParenExpr:
		Walk(v, n.X)

	case *SelectorExpr:
		Walk(v, n.X)
		Walk(v, n.Sel)

	case *IndexExpr:
		Walk(v, n.X)
		Walk(v, n.Index)

	case *IndexListExpr:
		Walk(v, n.X)
		walkList(v, n.Indices)

	case *SliceExpr:
		Walk(v, n.X)
		if n.Low != nil {
			Walk(v, n.Low)
		}

}

// IndexMapRType asserts that n is a map index operation, and returns
// an expression that yields the *runtime._type value representing the
// map type.
func IndexMapRType(pos src.XPos, n *ir.IndexExpr) ir.Node {
	assertOp(n, ir.OINDEXMAP)
	if hasRType(n, n.RType, "RType") {
		return n.RType
	}
	return mapRType(pos, n.X.Type())
}

// MakeChanRType asserts that n is a "make" operation for a channel

		case invalid:
			// ignore - error reported before
		case novalue:
			check.errorf(&x, NotAType, "%s used as type", &x)
		default:
			check.errorf(&x, NotAType, "%s is not a type", &x)
		}

	case *ast.IndexExpr, *ast.IndexListExpr:
		ix := typeparams.UnpackIndexExpr(e)
		check.verifyVersionf(inNode(e, ix.Lbrack), go1_18, "type instantiation")
		return check.instantiatedType(ix, def)

	case *ast.ParenExpr:

	{"CompositeLit", `struct{x, y int}@{}`},

	{"KeyValueExpr", `"foo"@: true`},
	{"KeyValueExpr", `"a"@: b`},

	{"FuncLit", `@func (){}`},
	{"ParenExpr", `@(x)`},
	{"SelectorExpr", `a@.b`},
	{"IndexExpr", `a@[i]`},

	{"SliceExpr", `a@[:]`},
	{"SliceExpr", `a@[i:]`},
	{"SliceExpr", `a@[:j]`},
	{"SliceExpr", `a@[i:j]`},
	{"SliceExpr", `a@[i:j:k]`},

	{"AssertExpr", `x@.(T)`},

	{"Operation", `@*b`},

		rhs.SetBounded(true)

		kidx := ir.NewIndexExpr(base.Pos, vstatk, i)
		kidx.SetBounded(true)

		// typechecker rewrites OINDEX to OINDEXMAP
		lhs := typecheck.AssignExpr(ir.NewIndexExpr(base.Pos, m, kidx)).(*ir.IndexExpr)
		base.AssertfAt(lhs.Op() == ir.OINDEXMAP, lhs.Pos(), "want OINDEXMAP, have %+v", lhs)
		lhs.RType = n.RType

		zero := ir.NewAssignStmt(base.Pos, i, ir.NewInt(base.Pos, 0))

		return
	}
	if n.Op() == ir.OINDEXMAP {
		n := n.(*ir.IndexExpr)
		n.Assigned = true
		return
	}

	defer n.SetType(nil)

	switch {
	case n.Op() == ir.ODOT && n.(*ir.SelectorExpr).X.Op() == ir.OINDEXMAP:
		base.Errorf("cannot assign to struct field %v in map", n)
	case (n.Op() == ir.OINDEX && n.(*ir.IndexExpr).X.Type().IsString()) || n.Op() == ir.OSLICESTR:

func recvString(recv ast.Expr) string {
	switch t := recv.(type) {
	case *ast.Ident:
		return t.Name
	case *ast.StarExpr:
		return "*" + recvString(t.X)
	case *ast.IndexExpr:
		// Generic type with one parameter.
		return fmt.Sprintf("%s[%s]", recvString(t.X), recvParam(t.Index))
	case *ast.IndexListExpr:
		// Generic type with multiple parameters.
		if len(t.Indices) > 0 {

		a.applyList(n, "Elts")

	case *ast.ParenExpr:
		a.apply(n, "X", nil, n.X)

	case *ast.SelectorExpr:
		a.apply(n, "X", nil, n.X)
		a.apply(n, "Sel", nil, n.Sel)

	case *ast.IndexExpr:
		a.apply(n, "X", nil, n.X)
		a.apply(n, "Index", nil, n.Index)

	case *ast.IndexListExpr:
		a.apply(n, "X", nil, n.X)
		a.applyList(n, "Indices")

	case *ast.SliceExpr:
		a.apply(n, "X", nil, n.X)