func()

in errors/fmt/scan.go [920:1021]

• 95 lines of code
• 34 McCabe index (conditional complexity)

func (s *ss) scanOne(verb rune, arg interface{}) {
	s.buf = s.buf[:0]
	var err error
	// If the parameter has its own Scan method, use that.
	if v, ok := arg.(Scanner); ok {
		err = v.Scan(s, verb)
		if err != nil {
			if err == io.EOF {
				err = io.ErrUnexpectedEOF
			}
			s.error(err)
		}
		return
	}

	switch v := arg.(type) {
	case *bool:
		*v = s.scanBool(verb)
	case *complex64:
		*v = complex64(s.scanComplex(verb, 64))
	case *complex128:
		*v = s.scanComplex(verb, 128)
	case *int:
		*v = int(s.scanInt(verb, intBits))
	case *int8:
		*v = int8(s.scanInt(verb, 8))
	case *int16:
		*v = int16(s.scanInt(verb, 16))
	case *int32:
		*v = int32(s.scanInt(verb, 32))
	case *int64:
		*v = s.scanInt(verb, 64)
	case *uint:
		*v = uint(s.scanUint(verb, intBits))
	case *uint8:
		*v = uint8(s.scanUint(verb, 8))
	case *uint16:
		*v = uint16(s.scanUint(verb, 16))
	case *uint32:
		*v = uint32(s.scanUint(verb, 32))
	case *uint64:
		*v = s.scanUint(verb, 64)
	case *uintptr:
		*v = uintptr(s.scanUint(verb, uintptrBits))
	// Floats are tricky because you want to scan in the precision of the result, not
	// scan in high precision and convert, in order to preserve the correct error condition.
	case *float32:
		if s.okVerb(verb, floatVerbs, "float32") {
			s.SkipSpace()
			s.notEOF()
			*v = float32(s.convertFloat(s.floatToken(), 32))
		}
	case *float64:
		if s.okVerb(verb, floatVerbs, "float64") {
			s.SkipSpace()
			s.notEOF()
			*v = s.convertFloat(s.floatToken(), 64)
		}
	case *string:
		*v = s.convertString(verb)
	case *[]byte:
		// We scan to string and convert so we get a copy of the data.
		// If we scanned to bytes, the slice would point at the buffer.
		*v = []byte(s.convertString(verb))
	default:
		val := reflect.ValueOf(v)
		ptr := val
		if ptr.Kind() != reflect.Ptr {
			s.errorString("type not a pointer: " + val.Type().String())
			return
		}
		switch v := ptr.Elem(); v.Kind() {
		case reflect.Bool:
			v.SetBool(s.scanBool(verb))
		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
			v.SetInt(s.scanInt(verb, v.Type().Bits()))
		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
			v.SetUint(s.scanUint(verb, v.Type().Bits()))
		case reflect.String:
			v.SetString(s.convertString(verb))
		case reflect.Slice:
			// For now, can only handle (renamed) []byte.
			typ := v.Type()
			if typ.Elem().Kind() != reflect.Uint8 {
				s.errorString("can't scan type: " + val.Type().String())
			}
			str := s.convertString(verb)
			v.Set(reflect.MakeSlice(typ, len(str), len(str)))
			for i := 0; i < len(str); i++ {
				v.Index(i).SetUint(uint64(str[i]))
			}
		case reflect.Float32, reflect.Float64:
			s.SkipSpace()
			s.notEOF()
			v.SetFloat(s.convertFloat(s.floatToken(), v.Type().Bits()))
		case reflect.Complex64, reflect.Complex128:
			v.SetComplex(s.scanComplex(verb, v.Type().Bits()))
		default:
			s.errorString("can't scan type: " + val.Type().String())
		}
	}
}