function inferDType()

in js/src/visitor.ts [136:221]
78 lines of code
52 McCabe index (conditional complexity)

function inferDType<T extends DataType>(type: T): Type {
    switch (type.typeId) {
        case Type.Null: return Type.Null;
        case Type.Int: {
            const { bitWidth, isSigned } = (type as any as Int);
            switch (bitWidth) {
                case 8: return isSigned ? Type.Int8 : Type.Uint8;
                case 16: return isSigned ? Type.Int16 : Type.Uint16;
                case 32: return isSigned ? Type.Int32 : Type.Uint32;
                case 64: return isSigned ? Type.Int64 : Type.Uint64;
            }
            // @ts-ignore
            return Type.Int;
        }
        case Type.Float:
            switch ((type as any as Float).precision) {
                case Precision.HALF: return Type.Float16;
                case Precision.SINGLE: return Type.Float32;
                case Precision.DOUBLE: return Type.Float64;
            }
            // @ts-ignore
            return Type.Float;
        case Type.Binary: return Type.Binary;
        case Type.LargeBinary: return Type.LargeBinary;
        case Type.Utf8: return Type.Utf8;
        case Type.LargeUtf8: return Type.LargeUtf8;
        case Type.Bool: return Type.Bool;
        case Type.Decimal: return Type.Decimal;
        case Type.Time:
            switch ((type as any as Time).unit) {
                case TimeUnit.SECOND: return Type.TimeSecond;
                case TimeUnit.MILLISECOND: return Type.TimeMillisecond;
                case TimeUnit.MICROSECOND: return Type.TimeMicrosecond;
                case TimeUnit.NANOSECOND: return Type.TimeNanosecond;
            }
            // @ts-ignore
            return Type.Time;
        case Type.Timestamp:
            switch ((type as any as Timestamp).unit) {
                case TimeUnit.SECOND: return Type.TimestampSecond;
                case TimeUnit.MILLISECOND: return Type.TimestampMillisecond;
                case TimeUnit.MICROSECOND: return Type.TimestampMicrosecond;
                case TimeUnit.NANOSECOND: return Type.TimestampNanosecond;
            }
            // @ts-ignore
            return Type.Timestamp;
        case Type.Date:
            switch ((type as any as Date_).unit) {
                case DateUnit.DAY: return Type.DateDay;
                case DateUnit.MILLISECOND: return Type.DateMillisecond;
            }
            // @ts-ignore
            return Type.Date;
        case Type.Interval:
            switch ((type as any as Interval).unit) {
                case IntervalUnit.DAY_TIME: return Type.IntervalDayTime;
                case IntervalUnit.YEAR_MONTH: return Type.IntervalYearMonth;
                case IntervalUnit.MONTH_DAY_NANO: return Type.IntervalMonthDayNano;
            }
            // @ts-ignore
            return Type.Interval;
        case Type.Duration:
            switch ((type as any as Duration).unit) {
                case TimeUnit.SECOND: return Type.DurationSecond;
                case TimeUnit.MILLISECOND: return Type.DurationMillisecond;
                case TimeUnit.MICROSECOND: return Type.DurationMicrosecond;
                case TimeUnit.NANOSECOND: return Type.DurationNanosecond;
            }
            // @ts-ignore
            return Type.Duration;
        case Type.Map: return Type.Map;
        case Type.List: return Type.List;
        case Type.Struct: return Type.Struct;
        case Type.Union:
            switch ((type as any as Union).mode) {
                case UnionMode.Dense: return Type.DenseUnion;
                case UnionMode.Sparse: return Type.SparseUnion;
            }
            // @ts-ignore
            return Type.Union;
        case Type.FixedSizeBinary: return Type.FixedSizeBinary;
        case Type.FixedSizeList: return Type.FixedSizeList;
        case Type.Dictionary: return Type.Dictionary;
    }
    throw new Error(`Unrecognized type '${Type[type.typeId]}'`);
}