f := i.M; f(7)  // like i.M(7)
</pre>


<h3 id="Index_expressions">Index expressions</h3>

<p>
A primary expression of the form
</p>

<pre>
a[x]
</pre>

<p>
denotes the element of the array, pointer to array, slice, string or map <code>a</code> indexed by <code>x</code>.
The value <code>x</code> is called the <i>index</i> or <i>map key</i>, respectively.
The following rules apply:

			this._values = [ // JS values that Go currently has references to, indexed by reference id
				NaN,
				0,
				null,
				true,
				false,
				globalThis,
				this,
			];
			this._goRefCounts = new Array(this._values.length).fill(Infinity); // number of references that Go has to a JS value, indexed by reference id
			this._ids = new Map([ // mapping from JS values to reference ids
				[0, 1],

		f.walk(n.Elts, ctxExpr, visit)
	case *ast.ParenExpr:
		f.walk(&n.X, context, visit)
	case *ast.SelectorExpr:
		f.walk(&n.X, ctxSelector, visit)
	case *ast.IndexExpr:
		f.walk(&n.X, ctxExpr, visit)
		f.walk(&n.Index, ctxExpr, visit)
	case *ast.SliceExpr:
		f.walk(&n.X, ctxExpr, visit)
		if n.Low != nil {
			f.walk(&n.Low, ctxExpr, visit)
		}
		if n.High != nil {
			f.walk(&n.High, ctxExpr, visit)
		}

					wantName = test.output[:len(test.output)-4]
					if strings.HasPrefix(wantName, "$") || strings.HasPrefix(wantName, "*") {
						wantName = wantName[1:]
					}
					if i := strings.Index(wantName, "+"); i >= 0 {
						wantName = wantName[:i]
					}
				}
				if ok != isFuncSym || name != wantName {

pkg syscall (netbsd-arm64-cgo), type IfaMsghdr struct, Addrs int32
pkg syscall (netbsd-arm64-cgo), type IfaMsghdr struct, Flags int32
pkg syscall (netbsd-arm64-cgo), type IfaMsghdr struct, Index uint16
pkg syscall (netbsd-arm64-cgo), type IfaMsghdr struct, Metric int32
pkg syscall (netbsd-arm64-cgo), type IfaMsghdr struct, Msglen uint16
pkg syscall (netbsd-arm64-cgo), type IfaMsghdr struct, Pad_cgo_0 [6]uint8

pkg go/types, method (*Scope) Pos() token.Pos
pkg go/types, method (*Scope) String() string
pkg go/types, method (*Scope) WriteTo(io.Writer, int, bool)
pkg go/types, method (*Selection) Index() []int
pkg go/types, method (*Selection) Indirect() bool
pkg go/types, method (*Selection) Kind() SelectionKind
pkg go/types, method (*Selection) Obj() Object
pkg go/types, method (*Selection) Recv() Type

	VADDPD (AX), Z1, K1, Z1          // 62f1f5495808
	VADDPD 8(R10), Z10, K4, Z10      // 6251ad4c589208000000
	VADDPD (R10)(AX*4), Z20, K7, Z20 // 62c1dd47582482
	// EVEX gather (also tests Z as VSIB index).
	VPGATHERDD 360(AX)(X2*4), K1, X1    // 62f27d09904c905a
	VPGATHERDD 640(BP)(X15*8), K3, X14  // 62327d0b90b4fd80020000
	VPGATHERDD 960(R10)(X25*2), K7, X24 // 62027d0790844ac0030000

func (r *negativeReader) Read([]byte) (int, error) { return -1, nil }

func TestNegativeRead(t *testing.T) {
	// should panic with a description pointing at the reader, not at itself.
	// (should NOT panic with slice index error, for example.)
	b := NewReader(new(negativeReader))
	defer func() {
		switch err := recover().(type) {
		case nil:
			t.Fatal("read did not panic")
		case error:

	// AVX512GATHER index/index #UD cases.
	VPGATHERQQ (BP)(X2*2), K1, X2   // ERROR "index and destination registers should be distinct"
	VPGATHERQQ (BP)(Y15*2), K1, Y15 // ERROR "index and destination registers should be distinct"
	VPGATHERQQ (BP)(Z20*2), K1, Z20 // ERROR "index and destination registers should be distinct"
	VPGATHERDQ (BP)(X2*2), K1, X2   // ERROR "index and destination registers should be distinct"

		}
		if r == tr {
			continue
		}
		return false
	}

	// One string is empty. Are both?
	return len(s) == len(t)
}

// Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.
func Index(s, sep []byte) int {
	n := len(sep)
	switch {
	case n == 0:
		return 0
	case n == 1:
		return IndexByte(s, sep[0])
	case n == len(s):