func arrayToJSON()

in arrow/internal/arrjson/arrjson.go [947:1216]
243 lines of code
35 McCabe index (conditional complexity)

func arrayToJSON(field arrow.Field, arr array.Interface) Array {
	switch arr := arr.(type) {
	case *array.Null:
		return Array{
			Name:  field.Name,
			Count: arr.Len(),
		}

	case *array.Boolean:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   boolsToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Int8:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   i8ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Int16:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   i16ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Int32:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   i32ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Int64:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   i64ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Uint8:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   u8ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Uint16:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   u16ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Uint32:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   u32ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Uint64:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   u64ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Float16:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   f16ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Float32:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   f32ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Float64:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   f64ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.String:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   strToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Binary:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   bytesToJSON(arr),
			Valids: validsToJSON(arr),
			Offset: arr.ValueOffsets(),
		}

	case *array.List:
		o := Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Valids: validsToJSON(arr),
			Offset: arr.Offsets(),
			Children: []Array{
				arrayToJSON(arrow.Field{Name: "item", Type: arr.DataType().(*arrow.ListType).Elem()}, arr.ListValues()),
			},
		}
		return o

	case *array.Map:
		o := Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Valids: validsToJSON(arr),
			Offset: arr.Offsets(),
			Children: []Array{
				arrayToJSON(arrow.Field{Name: "entries", Type: arr.DataType().(*arrow.MapType).ValueType()}, arr.ListValues()),
			},
		}
		return o

	case *array.FixedSizeList:
		o := Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Valids: validsToJSON(arr),
			Children: []Array{
				arrayToJSON(arrow.Field{Name: "", Type: arr.DataType().(*arrow.FixedSizeListType).Elem()}, arr.ListValues()),
			},
		}
		return o

	case *array.Struct:
		dt := arr.DataType().(*arrow.StructType)
		o := Array{
			Name:     field.Name,
			Count:    arr.Len(),
			Valids:   validsToJSON(arr),
			Children: make([]Array, len(dt.Fields())),
		}
		for i := range o.Children {
			o.Children[i] = arrayToJSON(dt.Field(i), arr.Field(i))
		}
		return o

	case *array.FixedSizeBinary:
		dt := arr.DataType().(*arrow.FixedSizeBinaryType)
		o := Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Valids: validsToJSON(arr),
			Data:   make([]interface{}, arr.Len()),
		}
		for i := range o.Data {
			v := []byte(strings.ToUpper(hex.EncodeToString(arr.Value(i))))
			if len(v) != 2*dt.ByteWidth {
				panic(xerrors.Errorf("arrjson: invalid hex-string length (got=%d, want=%d)", len(v), 2*dt.ByteWidth))
			}
			o.Data[i] = string(v) // re-convert as string to prevent json.Marshal from base64-encoding it.
		}
		return o

	case *array.Date32:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   date32ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Date64:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   date64ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Time32:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   time32ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Time64:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   time64ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Timestamp:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   timestampToJSON(arr),
			Valids: validsToJSON(arr),
		}
	case *array.MonthInterval:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   monthintervalToJSON(arr),
			Valids: validsToJSON(arr),
		}
	case *array.DayTimeInterval:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   daytimeintervalToJSON(arr),
			Valids: validsToJSON(arr),
		}
	case *array.MonthDayNanoInterval:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   monthDayNanointervalToJSON(arr),
			Valids: validsToJSON(arr),
		}
	case *array.Duration:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   durationToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case *array.Decimal128:
		return Array{
			Name:   field.Name,
			Count:  arr.Len(),
			Data:   decimal128ToJSON(arr),
			Valids: validsToJSON(arr),
		}

	case array.ExtensionArray:
		return arrayToJSON(field, arr.Storage())

	default:
		panic(xerrors.Errorf("unknown array type %T", arr))
	}
	panic("impossible")
}