func()

in internal/encoding/json/decode.go [509:599]
76 lines of code
22 McCabe index (conditional complexity)

func (d *decodeState) array(v reflect.Value) error {
	// Check for unmarshaler.
	u, ut, pv := indirect(v, false)
	if u != nil {
		start := d.readIndex()
		d.skip()
		return u.UnmarshalJSON(d.data[start:d.off])
	}
	if ut != nil {
		d.saveError(&UnmarshalTypeError{Value: "array", Type: v.Type(), Offset: int64(d.off)})
		d.skip()
		return nil
	}
	v = pv

	// Check type of target.
	switch v.Kind() {
	case reflect.Interface:
		if v.NumMethod() == 0 {
			// Decoding into nil interface? Switch to non-reflect code.
			ai := d.arrayInterface()
			v.Set(reflect.ValueOf(ai))
			return nil
		}
		// Otherwise it's invalid.
		fallthrough
	default:
		d.saveError(&UnmarshalTypeError{Value: "array", Type: v.Type(), Offset: int64(d.off)})
		d.skip()
		return nil
	case reflect.Array, reflect.Slice:
		break
	}

	i := 0
	for {
		// Look ahead for ] - can only happen on first iteration.
		d.scanWhile(scanSkipSpace)
		if d.opcode == scanEndArray {
			break
		}

		// Expand slice length, growing the slice if necessary.
		if v.Kind() == reflect.Slice {
			if i >= v.Cap() {
				v.Grow(1)
			}
			if i >= v.Len() {
				v.SetLen(i + 1)
			}
		}

		if i < v.Len() {
			// Decode into element.
			if err := d.value(v.Index(i)); err != nil {
				return err
			}
		} else {
			// Ran out of fixed array: skip.
			if err := d.value(reflect.Value{}); err != nil {
				return err
			}
		}
		i++

		// Next token must be , or ].
		if d.opcode == scanSkipSpace {
			d.scanWhile(scanSkipSpace)
		}
		if d.opcode == scanEndArray {
			break
		}
		if d.opcode != scanArrayValue {
			panic(phasePanicMsg)
		}
	}

	if i < v.Len() {
		if v.Kind() == reflect.Array {
			for ; i < v.Len(); i++ {
				v.Index(i).SetZero() // zero remainder of array
			}
		} else {
			v.SetLen(i) // truncate the slice
		}
	}
	if i == 0 && v.Kind() == reflect.Slice {
		v.Set(reflect.MakeSlice(v.Type(), 0, 0))
	}
	return nil
}