Skip to main content

arrow_schema/
datatype.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use std::str::FromStr;
19use std::sync::Arc;
20
21use crate::{ArrowError, Field, FieldRef, Fields, UnionFields};
22
23/// Datatypes supported by this implementation of Apache Arrow.
24///
25/// The variants of this enum include primitive fixed size types as well as
26/// parametric or nested types. See [`Schema.fbs`] for Arrow's specification.
27///
28/// # Examples
29///
30/// Primitive types
31/// ```
32/// # use arrow_schema::DataType;
33/// // create a new 32-bit signed integer
34/// let data_type = DataType::Int32;
35/// ```
36///
37/// Nested Types
38/// ```
39/// # use arrow_schema::{DataType, Field};
40/// # use std::sync::Arc;
41/// // create a new list of 32-bit signed integers directly
42/// let list_data_type = DataType::List(Arc::new(Field::new_list_field(DataType::Int32, true)));
43/// // Create the same list type with constructor
44/// let list_data_type2 = DataType::new_list(DataType::Int32, true);
45/// assert_eq!(list_data_type, list_data_type2);
46/// ```
47///
48/// Dictionary Types
49/// ```
50/// # use arrow_schema::{DataType};
51/// // String Dictionary (key type Int32 and value type Utf8)
52/// let data_type = DataType::Dictionary(Box::new(DataType::Int32), Box::new(DataType::Utf8));
53/// ```
54///
55/// Timestamp Types
56/// ```
57/// # use arrow_schema::{DataType, TimeUnit};
58/// // timestamp with millisecond precision without timezone specified
59/// let data_type = DataType::Timestamp(TimeUnit::Millisecond, None);
60/// // timestamp with nanosecond precision in UTC timezone
61/// let data_type = DataType::Timestamp(TimeUnit::Nanosecond, Some("UTC".into()));
62///```
63///
64/// # Display and FromStr
65///
66/// The `Display` and `FromStr` implementations for `DataType` are
67/// human-readable, parseable, and reversible.
68///
69/// ```
70/// # use arrow_schema::DataType;
71/// let data_type = DataType::Dictionary(Box::new(DataType::Int32), Box::new(DataType::Utf8));
72/// let data_type_string = data_type.to_string();
73/// assert_eq!(data_type_string, "Dictionary(Int32, Utf8)");
74/// // display can be parsed back into the original type
75/// let parsed_data_type: DataType = data_type.to_string().parse().unwrap();
76/// assert_eq!(data_type, parsed_data_type);
77/// ```
78///
79/// # Nested Support
80/// Currently, the Rust implementation supports the following nested types:
81///  - `List<T>`
82///  - `LargeList<T>`
83///  - `FixedSizeList<T>`
84///  - `Struct<T, U, V, ...>`
85///  - `Union<T, U, V, ...>`
86///  - `Map<K, V>`
87///
88/// Nested types can themselves be nested within other arrays.
89/// For more information on these types please see
90/// [the physical memory layout of Apache Arrow]
91///
92/// [`Schema.fbs`]: https://github.com/apache/arrow/blob/main/format/Schema.fbs
93/// [the physical memory layout of Apache Arrow]: https://arrow.apache.org/docs/format/Columnar.html#physical-memory-layout
94#[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
95#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
96pub enum DataType {
97    /// Null type
98    Null,
99    /// A boolean datatype representing the values `true` and `false`.
100    Boolean,
101    /// A signed 8-bit integer.
102    Int8,
103    /// A signed 16-bit integer.
104    Int16,
105    /// A signed 32-bit integer.
106    Int32,
107    /// A signed 64-bit integer.
108    Int64,
109    /// An unsigned 8-bit integer.
110    UInt8,
111    /// An unsigned 16-bit integer.
112    UInt16,
113    /// An unsigned 32-bit integer.
114    UInt32,
115    /// An unsigned 64-bit integer.
116    UInt64,
117    /// A 16-bit floating point number.
118    Float16,
119    /// A 32-bit floating point number.
120    Float32,
121    /// A 64-bit floating point number.
122    Float64,
123    /// A timestamp with an optional timezone.
124    ///
125    /// Time is measured as a Unix epoch, counting the seconds from
126    /// 00:00:00.000 on 1 January 1970, excluding leap seconds,
127    /// as a signed 64-bit integer.
128    ///
129    /// The time zone is a string indicating the name of a time zone, one of:
130    ///
131    /// * As used in the Olson time zone database (the "tz database" or
132    ///   "tzdata"), such as "America/New_York"
133    /// * An absolute time zone offset of the form +XX:XX or -XX:XX, such as +07:30
134    ///
135    /// Timestamps with a non-empty timezone
136    /// ------------------------------------
137    ///
138    /// If a Timestamp column has a non-empty timezone value, its epoch is
139    /// 1970-01-01 00:00:00 (January 1st 1970, midnight) in the *UTC* timezone
140    /// (the Unix epoch), regardless of the Timestamp's own timezone.
141    ///
142    /// Therefore, timestamp values with a non-empty timezone correspond to
143    /// physical points in time together with some additional information about
144    /// how the data was obtained and/or how to display it (the timezone).
145    ///
146    ///   For example, the timestamp value 0 with the timezone string "Europe/Paris"
147    ///   corresponds to "January 1st 1970, 00h00" in the UTC timezone, but the
148    ///   application may prefer to display it as "January 1st 1970, 01h00" in
149    ///   the Europe/Paris timezone (which is the same physical point in time).
150    ///
151    /// One consequence is that timestamp values with a non-empty timezone
152    /// can be compared and ordered directly, since they all share the same
153    /// well-known point of reference (the Unix epoch).
154    ///
155    /// Timestamps with an unset / empty timezone
156    /// -----------------------------------------
157    ///
158    /// If a Timestamp column has no timezone value, its epoch is
159    /// 1970-01-01 00:00:00 (January 1st 1970, midnight) in an *unknown* timezone.
160    ///
161    /// Therefore, timestamp values without a timezone cannot be meaningfully
162    /// interpreted as physical points in time, but only as calendar / clock
163    /// indications ("wall clock time") in an unspecified timezone.
164    ///
165    ///   For example, the timestamp value 0 with an empty timezone string
166    ///   corresponds to "January 1st 1970, 00h00" in an unknown timezone: there
167    ///   is not enough information to interpret it as a well-defined physical
168    ///   point in time.
169    ///
170    /// One consequence is that timestamp values without a timezone cannot
171    /// be reliably compared or ordered, since they may have different points of
172    /// reference.  In particular, it is *not* possible to interpret an unset
173    /// or empty timezone as the same as "UTC".
174    ///
175    /// Conversion between timezones
176    /// ----------------------------
177    ///
178    /// If a Timestamp column has a non-empty timezone, changing the timezone
179    /// to a different non-empty value is a metadata-only operation:
180    /// the timestamp values need not change as their point of reference remains
181    /// the same (the Unix epoch).
182    ///
183    /// However, if a Timestamp column has no timezone value, changing it to a
184    /// non-empty value requires to think about the desired semantics.
185    /// One possibility is to assume that the original timestamp values are
186    /// relative to the epoch of the timezone being set; timestamp values should
187    /// then adjusted to the Unix epoch (for example, changing the timezone from
188    /// empty to "Europe/Paris" would require converting the timestamp values
189    /// from "Europe/Paris" to "UTC", which seems counter-intuitive but is
190    /// nevertheless correct).
191    ///
192    /// ```
193    /// # use arrow_schema::{DataType, TimeUnit};
194    /// DataType::Timestamp(TimeUnit::Second, None);
195    /// DataType::Timestamp(TimeUnit::Second, Some("literal".into()));
196    /// DataType::Timestamp(TimeUnit::Second, Some("string".to_string().into()));
197    /// ```
198    ///
199    /// # Timezone representation
200    /// ----------------------------
201    /// It is possible to use either the timezone string representation, such as "UTC", or the absolute time zone offset "+00:00".
202    /// For timezones with fixed offsets, such as "UTC" or "JST", the offset representation is recommended, as it is more explicit and less ambiguous.
203    ///
204    /// Most arrow-rs functionalities use the absolute offset representation,
205    /// such as [`PrimitiveArray::with_timezone_utc`] that applies a
206    /// UTC timezone to timestamp arrays.
207    ///
208    /// [`PrimitiveArray::with_timezone_utc`]: https://docs.rs/arrow/latest/arrow/array/struct.PrimitiveArray.html#method.with_timezone_utc
209    ///
210    /// Timezone string parsing
211    /// -----------------------
212    /// When feature `chrono-tz` is not enabled, allowed timezone strings are fixed offsets of the form "+09:00", "-09" or "+0930".
213    ///
214    /// When feature `chrono-tz` is enabled, additional strings supported by [chrono_tz](https://docs.rs/chrono-tz/latest/chrono_tz/)
215    /// are also allowed, which include [IANA database](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones)
216    /// timezones.
217    Timestamp(TimeUnit, Option<Arc<str>>),
218    /// A signed 32-bit date representing the elapsed time since UNIX epoch (1970-01-01)
219    /// in days.
220    Date32,
221    /// A signed 64-bit date representing the elapsed time since UNIX epoch (1970-01-01)
222    /// in milliseconds.
223    ///
224    /// # Valid Ranges
225    ///
226    /// According to the Arrow specification ([Schema.fbs]), values of Date64
227    /// are treated as the number of *days*, in milliseconds, since the UNIX
228    /// epoch. Therefore, values of this type  must be evenly divisible by
229    /// `86_400_000`, the number of milliseconds in a standard day.
230    ///
231    /// It is not valid to store milliseconds that do not represent an exact
232    /// day. The reason for this restriction is compatibility with other
233    /// language's native libraries (specifically Java), which historically
234    /// lacked a dedicated date type and only supported timestamps.
235    ///
236    /// # Validation
237    ///
238    /// This library does not validate or enforce that Date64 values are evenly
239    /// divisible by `86_400_000`  for performance and usability reasons. Date64
240    /// values are treated similarly to `Timestamp(TimeUnit::Millisecond,
241    /// None)`: values will be displayed with a time of day if the value does
242    /// not represent an exact day, and arithmetic will be done at the
243    /// millisecond granularity.
244    ///
245    /// # Recommendation
246    ///
247    /// Users should prefer [`Date32`] to cleanly represent the number
248    /// of days, or one of the Timestamp variants to include time as part of the
249    /// representation, depending on their use case.
250    ///
251    /// # Further Reading
252    ///
253    /// For more details, see [#5288](https://github.com/apache/arrow-rs/issues/5288).
254    ///
255    /// [`Date32`]: Self::Date32
256    /// [Schema.fbs]: https://github.com/apache/arrow/blob/main/format/Schema.fbs
257    Date64,
258    /// A signed 32-bit time representing the elapsed time since midnight in the unit of `TimeUnit`.
259    /// Must be either seconds or milliseconds.
260    Time32(TimeUnit),
261    /// A signed 64-bit time representing the elapsed time since midnight in the unit of `TimeUnit`.
262    /// Must be either microseconds or nanoseconds.
263    Time64(TimeUnit),
264    /// Measure of elapsed time in either seconds, milliseconds, microseconds or nanoseconds.
265    Duration(TimeUnit),
266    /// A "calendar" interval which models types that don't necessarily
267    /// have a precise duration without the context of a base timestamp (e.g.
268    /// days can differ in length during day light savings time transitions).
269    Interval(IntervalUnit),
270    /// Opaque binary data of variable length.
271    ///
272    /// A single Binary array can store up to [`i32::MAX`] bytes
273    /// of binary data in total.
274    Binary,
275    /// Opaque binary data of fixed size.
276    /// Enum parameter specifies the number of bytes per value.
277    FixedSizeBinary(i32),
278    /// Opaque binary data of variable length and 64-bit offsets.
279    ///
280    /// A single LargeBinary array can store up to [`i64::MAX`] bytes
281    /// of binary data in total.
282    LargeBinary,
283    /// Opaque binary data of variable length.
284    ///
285    /// Logically the same as [`Binary`], but the internal representation uses a view
286    /// struct that contains the string length and either the string's entire data
287    /// inline (for small strings) or an inlined prefix, an index of another buffer,
288    /// and an offset pointing to a slice in that buffer (for non-small strings).
289    ///
290    /// [`Binary`]: Self::Binary
291    BinaryView,
292    /// A variable-length string in Unicode with UTF-8 encoding.
293    ///
294    /// A single Utf8 array can store up to [`i32::MAX`] bytes
295    /// of string data in total.
296    Utf8,
297    /// A variable-length string in Unicode with UFT-8 encoding and 64-bit offsets.
298    ///
299    /// A single LargeUtf8 array can store up to [`i64::MAX`] bytes
300    /// of string data in total.
301    LargeUtf8,
302    /// A variable-length string in Unicode with UTF-8 encoding
303    ///
304    /// Logically the same as [`Utf8`], but the internal representation uses a view
305    /// struct that contains the string length and either the string's entire data
306    /// inline (for small strings) or an inlined prefix, an index of another buffer,
307    /// and an offset pointing to a slice in that buffer (for non-small strings).
308    ///
309    /// [`Utf8`]: Self::Utf8
310    Utf8View,
311    /// A list of some logical data type with variable length.
312    ///
313    /// A single List array can store up to [`i32::MAX`] elements in total.
314    List(FieldRef),
315
316    /// A list of some logical data type with variable length.
317    ///
318    /// Logically the same as [`List`], but the internal representation differs in how child
319    /// data is referenced, allowing flexibility in how data is layed out.
320    ///
321    /// [`List`]: Self::List
322    ListView(FieldRef),
323    /// A list of some logical data type with fixed length.
324    FixedSizeList(FieldRef, i32),
325    /// A list of some logical data type with variable length and 64-bit offsets.
326    ///
327    /// A single LargeList array can store up to [`i64::MAX`] elements in total.
328    LargeList(FieldRef),
329
330    /// A list of some logical data type with variable length and 64-bit offsets.
331    ///
332    /// Logically the same as [`LargeList`], but the internal representation differs in how child
333    /// data is referenced, allowing flexibility in how data is layed out.
334    ///
335    /// [`LargeList`]: Self::LargeList
336    LargeListView(FieldRef),
337    /// A nested datatype that contains a number of sub-fields.
338    Struct(Fields),
339    /// A nested datatype that can represent slots of differing types. Components:
340    ///
341    /// 1. [`UnionFields`]
342    /// 2. The type of union (Sparse or Dense)
343    Union(UnionFields, UnionMode),
344    /// A dictionary encoded array (`key_type`, `value_type`), where
345    /// each array element is an index of `key_type` into an
346    /// associated dictionary of `value_type`.
347    ///
348    /// Dictionary arrays are used to store columns of `value_type`
349    /// that contain many repeated values using less memory, but with
350    /// a higher CPU overhead for some operations.
351    ///
352    /// This type mostly used to represent low cardinality string
353    /// arrays or a limited set of primitive types as integers.
354    Dictionary(Box<DataType>, Box<DataType>),
355    /// Exact 32-bit width decimal value with precision and scale
356    ///
357    /// * precision is the total number of digits
358    /// * scale is the number of digits past the decimal
359    ///
360    /// For example the number 123.45 has precision 5 and scale 2.
361    ///
362    /// In certain situations, scale could be negative number. For
363    /// negative scale, it is the number of padding 0 to the right
364    /// of the digits.
365    ///
366    /// For example the number 12300 could be treated as a decimal
367    /// has precision 3 and scale -2.
368    Decimal32(u8, i8),
369    /// Exact 64-bit width decimal value with precision and scale
370    ///
371    /// * precision is the total number of digits
372    /// * scale is the number of digits past the decimal
373    ///
374    /// For example the number 123.45 has precision 5 and scale 2.
375    ///
376    /// In certain situations, scale could be negative number. For
377    /// negative scale, it is the number of padding 0 to the right
378    /// of the digits.
379    ///
380    /// For example the number 12300 could be treated as a decimal
381    /// has precision 3 and scale -2.
382    Decimal64(u8, i8),
383    /// Exact 128-bit width decimal value with precision and scale
384    ///
385    /// * precision is the total number of digits
386    /// * scale is the number of digits past the decimal
387    ///
388    /// For example the number 123.45 has precision 5 and scale 2.
389    ///
390    /// In certain situations, scale could be negative number. For
391    /// negative scale, it is the number of padding 0 to the right
392    /// of the digits.
393    ///
394    /// For example the number 12300 could be treated as a decimal
395    /// has precision 3 and scale -2.
396    Decimal128(u8, i8),
397    /// Exact 256-bit width decimal value with precision and scale
398    ///
399    /// * precision is the total number of digits
400    /// * scale is the number of digits past the decimal
401    ///
402    /// For example the number 123.45 has precision 5 and scale 2.
403    ///
404    /// In certain situations, scale could be negative number. For
405    /// negative scale, it is the number of padding 0 to the right
406    /// of the digits.
407    ///
408    /// For example the number 12300 could be treated as a decimal
409    /// has precision 3 and scale -2.
410    Decimal256(u8, i8),
411    /// A Map is a logical nested type that is represented as
412    ///
413    /// `List<entries: Struct<key: K, value: V>>`
414    ///
415    /// The keys and values are each respectively contiguous.
416    /// The key and value types are not constrained, but keys should be
417    /// hashable and unique.
418    /// Whether the keys are sorted can be set in the `bool` after the `Field`.
419    ///
420    /// In a field with Map type, the field has a child Struct field, which then
421    /// has two children: key type and the second the value type. The names of the
422    /// child fields may be respectively "entries", "key", and "value", but this is
423    /// not enforced.
424    Map(FieldRef, bool),
425    /// A run-end encoding (REE) is a variation of run-length encoding (RLE). These
426    /// encodings are well-suited for representing data containing sequences of the
427    /// same value, called runs. Each run is represented as a value and an integer giving
428    /// the index in the array where the run ends.
429    ///
430    /// A run-end encoded array has no buffers by itself, but has two child arrays. The
431    /// first child array, called the run ends array, holds either 16, 32, or 64-bit
432    /// signed integers. The actual values of each run are held in the second child array.
433    ///
434    /// These child arrays are prescribed the standard names of "run_ends" and "values"
435    /// respectively.
436    RunEndEncoded(FieldRef, FieldRef),
437}
438
439/// An absolute length of time in seconds, milliseconds, microseconds or nanoseconds.
440#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
441#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
442pub enum TimeUnit {
443    /// Time in seconds.
444    Second,
445    /// Time in milliseconds.
446    Millisecond,
447    /// Time in microseconds.
448    Microsecond,
449    /// Time in nanoseconds.
450    Nanosecond,
451}
452
453impl std::fmt::Display for TimeUnit {
454    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
455        match self {
456            TimeUnit::Second => write!(f, "s"),
457            TimeUnit::Millisecond => write!(f, "ms"),
458            TimeUnit::Microsecond => write!(f, "µs"),
459            TimeUnit::Nanosecond => write!(f, "ns"),
460        }
461    }
462}
463
464/// YEAR_MONTH, DAY_TIME, MONTH_DAY_NANO interval in SQL style.
465#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, PartialOrd, Ord)]
466#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
467pub enum IntervalUnit {
468    /// Indicates the number of elapsed whole months, stored as 4-byte integers.
469    YearMonth,
470    /// Indicates the number of elapsed days and milliseconds,
471    /// stored as 2 contiguous 32-bit integers (days, milliseconds) (8-bytes in total).
472    DayTime,
473    /// A triple of the number of elapsed months, days, and nanoseconds.
474    /// The values are stored contiguously in 16 byte blocks. Months and
475    /// days are encoded as 32 bit integers and nanoseconds is encoded as a
476    /// 64 bit integer. All integers are signed. Each field is independent
477    /// (e.g. there is no constraint that nanoseconds have the same sign
478    /// as days or that the quantity of nanoseconds represents less
479    /// than a day's worth of time).
480    MonthDayNano,
481}
482
483/// Sparse or Dense union layouts
484#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Copy)]
485#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
486pub enum UnionMode {
487    /// Sparse union layout
488    Sparse,
489    /// Dense union layout
490    Dense,
491}
492
493/// Parses `str` into a `DataType`.
494///
495/// This is the reverse of [`DataType`]'s `Display`
496/// impl, and maintains the invariant that
497/// `DataType::try_from(&data_type.to_string()).unwrap() == data_type`
498///
499/// # Example
500/// ```
501/// use arrow_schema::DataType;
502///
503/// let data_type: DataType = "Int32".parse().unwrap();
504/// assert_eq!(data_type, DataType::Int32);
505/// ```
506impl FromStr for DataType {
507    type Err = ArrowError;
508
509    fn from_str(s: &str) -> Result<Self, Self::Err> {
510        crate::datatype_parse::parse_data_type(s)
511    }
512}
513
514impl TryFrom<&str> for DataType {
515    type Error = ArrowError;
516
517    fn try_from(value: &str) -> Result<Self, Self::Error> {
518        value.parse()
519    }
520}
521
522impl DataType {
523    /// Returns true if the type is primitive: (numeric, temporal).
524    #[inline]
525    pub fn is_primitive(&self) -> bool {
526        self.is_numeric() || self.is_temporal()
527    }
528
529    /// Returns true if this type is numeric: (UInt*, Int*, Float*, Decimal*).
530    #[inline]
531    pub fn is_numeric(&self) -> bool {
532        use DataType::*;
533        matches!(
534            self,
535            UInt8
536                | UInt16
537                | UInt32
538                | UInt64
539                | Int8
540                | Int16
541                | Int32
542                | Int64
543                | Float16
544                | Float32
545                | Float64
546                | Decimal32(_, _)
547                | Decimal64(_, _)
548                | Decimal128(_, _)
549                | Decimal256(_, _)
550        )
551    }
552
553    /// Returns true if this type is temporal: (Date*, Time*, Duration, or Interval).
554    #[inline]
555    pub fn is_temporal(&self) -> bool {
556        use DataType::*;
557        matches!(
558            self,
559            Date32 | Date64 | Timestamp(_, _) | Time32(_) | Time64(_) | Duration(_) | Interval(_)
560        )
561    }
562
563    /// Returns true if this type is floating: (Float*).
564    #[inline]
565    pub fn is_floating(&self) -> bool {
566        use DataType::*;
567        matches!(self, Float16 | Float32 | Float64)
568    }
569
570    /// Returns true if this type is integer: (Int*, UInt*).
571    #[inline]
572    pub fn is_integer(&self) -> bool {
573        self.is_signed_integer() || self.is_unsigned_integer()
574    }
575
576    /// Returns true if this type is signed integer: (Int*).
577    #[inline]
578    pub fn is_signed_integer(&self) -> bool {
579        use DataType::*;
580        matches!(self, Int8 | Int16 | Int32 | Int64)
581    }
582
583    /// Returns true if this type is unsigned integer: (UInt*).
584    #[inline]
585    pub fn is_unsigned_integer(&self) -> bool {
586        use DataType::*;
587        matches!(self, UInt8 | UInt16 | UInt32 | UInt64)
588    }
589
590    /// Returns true if this type is decimal: (Decimal*).
591    #[inline]
592    pub fn is_decimal(&self) -> bool {
593        use DataType::*;
594        matches!(
595            self,
596            Decimal32(..) | Decimal64(..) | Decimal128(..) | Decimal256(..)
597        )
598    }
599
600    /// Returns true if this type is valid as a dictionary key
601    #[inline]
602    pub fn is_dictionary_key_type(&self) -> bool {
603        self.is_integer()
604    }
605
606    /// Returns true if this type is valid for run-ends array in RunArray
607    #[inline]
608    pub fn is_run_ends_type(&self) -> bool {
609        use DataType::*;
610        matches!(self, Int16 | Int32 | Int64)
611    }
612
613    /// Returns true if this type is nested (List, FixedSizeList, LargeList, ListView. LargeListView, Struct, Union,
614    /// or Map), or a dictionary of a nested type
615    #[inline]
616    pub fn is_nested(&self) -> bool {
617        use DataType::*;
618        match self {
619            Dictionary(_, v) => DataType::is_nested(v.as_ref()),
620            RunEndEncoded(_, v) => DataType::is_nested(v.data_type()),
621            List(_)
622            | FixedSizeList(_, _)
623            | LargeList(_)
624            | ListView(_)
625            | LargeListView(_)
626            | Struct(_)
627            | Union(_, _)
628            | Map(_, _) => true,
629            _ => false,
630        }
631    }
632
633    /// Returns true if this type is DataType::Null.
634    #[inline]
635    pub fn is_null(&self) -> bool {
636        use DataType::*;
637        matches!(self, Null)
638    }
639
640    /// Returns true if this type is a String type
641    #[inline]
642    pub fn is_string(&self) -> bool {
643        use DataType::*;
644        matches!(self, Utf8 | LargeUtf8 | Utf8View)
645    }
646
647    /// Returns true if this type is a List type.
648    ///
649    /// List types include List, LargeList, FixedSizeList, ListView, and LargeListView.
650    #[inline]
651    pub fn is_list(&self) -> bool {
652        use DataType::*;
653        matches!(
654            self,
655            List(_) | LargeList(_) | FixedSizeList(_, _) | ListView(_) | LargeListView(_)
656        )
657    }
658
659    /// Returns true if this type is a Binary type.
660    ///
661    /// Binary types include Binary, LargeBinary, FixedSizeBinary and BinaryView.
662    #[inline]
663    pub fn is_binary(&self) -> bool {
664        use DataType::*;
665        matches!(self, Binary | LargeBinary | FixedSizeBinary(_) | BinaryView)
666    }
667
668    /// Compares the datatype with another, ignoring nested field names
669    /// and metadata.
670    pub fn equals_datatype(&self, other: &DataType) -> bool {
671        match (&self, other) {
672            (DataType::List(a), DataType::List(b))
673            | (DataType::LargeList(a), DataType::LargeList(b))
674            | (DataType::ListView(a), DataType::ListView(b))
675            | (DataType::LargeListView(a), DataType::LargeListView(b)) => {
676                a.is_nullable() == b.is_nullable() && a.data_type().equals_datatype(b.data_type())
677            }
678            (DataType::FixedSizeList(a, a_size), DataType::FixedSizeList(b, b_size)) => {
679                a_size == b_size
680                    && a.is_nullable() == b.is_nullable()
681                    && a.data_type().equals_datatype(b.data_type())
682            }
683            (DataType::Struct(a), DataType::Struct(b)) => {
684                a.len() == b.len()
685                    && a.iter().zip(b).all(|(a, b)| {
686                        a.is_nullable() == b.is_nullable()
687                            && a.data_type().equals_datatype(b.data_type())
688                    })
689            }
690            (DataType::Map(a_field, a_is_sorted), DataType::Map(b_field, b_is_sorted)) => {
691                a_field.is_nullable() == b_field.is_nullable()
692                    && a_field.data_type().equals_datatype(b_field.data_type())
693                    && a_is_sorted == b_is_sorted
694            }
695            (DataType::Dictionary(a_key, a_value), DataType::Dictionary(b_key, b_value)) => {
696                a_key.equals_datatype(b_key) && a_value.equals_datatype(b_value)
697            }
698            (
699                DataType::RunEndEncoded(a_run_ends, a_values),
700                DataType::RunEndEncoded(b_run_ends, b_values),
701            ) => {
702                a_run_ends.is_nullable() == b_run_ends.is_nullable()
703                    && a_run_ends
704                        .data_type()
705                        .equals_datatype(b_run_ends.data_type())
706                    && a_values.is_nullable() == b_values.is_nullable()
707                    && a_values.data_type().equals_datatype(b_values.data_type())
708            }
709            (
710                DataType::Union(a_union_fields, a_union_mode),
711                DataType::Union(b_union_fields, b_union_mode),
712            ) => {
713                a_union_mode == b_union_mode
714                    && a_union_fields.len() == b_union_fields.len()
715                    && a_union_fields.iter().all(|a| {
716                        b_union_fields.iter().any(|b| {
717                            a.0 == b.0
718                                && a.1.is_nullable() == b.1.is_nullable()
719                                && a.1.data_type().equals_datatype(b.1.data_type())
720                        })
721                    })
722            }
723            _ => self == other,
724        }
725    }
726
727    /// Returns the byte width of this type if it is a primitive type
728    ///
729    /// Returns `None` if not a primitive type
730    #[inline]
731    pub fn primitive_width(&self) -> Option<usize> {
732        match self {
733            DataType::Null => None,
734            DataType::Boolean => None,
735            DataType::Int8 | DataType::UInt8 => Some(1),
736            DataType::Int16 | DataType::UInt16 | DataType::Float16 => Some(2),
737            DataType::Int32 | DataType::UInt32 | DataType::Float32 => Some(4),
738            DataType::Int64 | DataType::UInt64 | DataType::Float64 => Some(8),
739            DataType::Timestamp(_, _) => Some(8),
740            DataType::Date32 | DataType::Time32(_) => Some(4),
741            DataType::Date64 | DataType::Time64(_) => Some(8),
742            DataType::Duration(_) => Some(8),
743            DataType::Interval(IntervalUnit::YearMonth) => Some(4),
744            DataType::Interval(IntervalUnit::DayTime) => Some(8),
745            DataType::Interval(IntervalUnit::MonthDayNano) => Some(16),
746            DataType::Decimal32(_, _) => Some(4),
747            DataType::Decimal64(_, _) => Some(8),
748            DataType::Decimal128(_, _) => Some(16),
749            DataType::Decimal256(_, _) => Some(32),
750            DataType::Utf8 | DataType::LargeUtf8 | DataType::Utf8View => None,
751            DataType::Binary | DataType::LargeBinary | DataType::BinaryView => None,
752            DataType::FixedSizeBinary(_) => None,
753            DataType::List(_)
754            | DataType::ListView(_)
755            | DataType::LargeList(_)
756            | DataType::LargeListView(_)
757            | DataType::Map(_, _) => None,
758            DataType::FixedSizeList(_, _) => None,
759            DataType::Struct(_) => None,
760            DataType::Union(_, _) => None,
761            DataType::Dictionary(_, _) => None,
762            DataType::RunEndEncoded(_, _) => None,
763        }
764    }
765
766    /// Return size of this instance in bytes.
767    ///
768    /// Includes the size of `Self`.
769    pub fn size(&self) -> usize {
770        std::mem::size_of_val(self)
771            + match self {
772                DataType::Null
773                | DataType::Boolean
774                | DataType::Int8
775                | DataType::Int16
776                | DataType::Int32
777                | DataType::Int64
778                | DataType::UInt8
779                | DataType::UInt16
780                | DataType::UInt32
781                | DataType::UInt64
782                | DataType::Float16
783                | DataType::Float32
784                | DataType::Float64
785                | DataType::Date32
786                | DataType::Date64
787                | DataType::Time32(_)
788                | DataType::Time64(_)
789                | DataType::Duration(_)
790                | DataType::Interval(_)
791                | DataType::Binary
792                | DataType::FixedSizeBinary(_)
793                | DataType::LargeBinary
794                | DataType::BinaryView
795                | DataType::Utf8
796                | DataType::LargeUtf8
797                | DataType::Utf8View
798                | DataType::Decimal32(_, _)
799                | DataType::Decimal64(_, _)
800                | DataType::Decimal128(_, _)
801                | DataType::Decimal256(_, _) => 0,
802                DataType::Timestamp(_, s) => s.as_ref().map(|s| s.len()).unwrap_or_default(),
803                DataType::List(field)
804                | DataType::ListView(field)
805                | DataType::FixedSizeList(field, _)
806                | DataType::LargeList(field)
807                | DataType::LargeListView(field)
808                | DataType::Map(field, _) => field.size(),
809                DataType::Struct(fields) => fields.size(),
810                DataType::Union(fields, _) => fields.size(),
811                DataType::Dictionary(dt1, dt2) => dt1.size() + dt2.size(),
812                DataType::RunEndEncoded(run_ends, values) => {
813                    run_ends.size() - std::mem::size_of_val(run_ends) + values.size()
814                        - std::mem::size_of_val(values)
815                }
816            }
817    }
818
819    /// Check to see if `self` is a superset of `other`
820    ///
821    /// If DataType is a nested type, then it will check to see if the nested type is a superset of the other nested type
822    /// else it will check to see if the DataType is equal to the other DataType
823    pub fn contains(&self, other: &DataType) -> bool {
824        match (self, other) {
825            (DataType::List(f1), DataType::List(f2))
826            | (DataType::LargeList(f1), DataType::LargeList(f2))
827            | (DataType::ListView(f1), DataType::ListView(f2))
828            | (DataType::LargeListView(f1), DataType::LargeListView(f2)) => f1.contains(f2),
829            (DataType::FixedSizeList(f1, s1), DataType::FixedSizeList(f2, s2)) => {
830                s1 == s2 && f1.contains(f2)
831            }
832            (DataType::Map(f1, s1), DataType::Map(f2, s2)) => s1 == s2 && f1.contains(f2),
833            (DataType::Struct(f1), DataType::Struct(f2)) => f1.contains(f2),
834            (DataType::Union(f1, s1), DataType::Union(f2, s2)) => {
835                s1 == s2
836                    && f1
837                        .iter()
838                        .all(|f1| f2.iter().any(|f2| f1.0 == f2.0 && f1.1.contains(f2.1)))
839            }
840            (DataType::Dictionary(k1, v1), DataType::Dictionary(k2, v2)) => {
841                k1.contains(k2) && v1.contains(v2)
842            }
843            _ => self == other,
844        }
845    }
846
847    /// Create a [`DataType::List`] with elements of the specified type
848    /// and nullability, and conventionally named inner [`Field`] (`"item"`).
849    ///
850    /// To specify field level metadata, construct the inner [`Field`]
851    /// directly via [`Field::new`] or [`Field::new_list_field`].
852    pub fn new_list(data_type: DataType, nullable: bool) -> Self {
853        DataType::List(Arc::new(Field::new_list_field(data_type, nullable)))
854    }
855
856    /// Create a [`DataType::LargeList`] with elements of the specified type
857    /// and nullability, and conventionally named inner [`Field`] (`"item"`).
858    ///
859    /// To specify field level metadata, construct the inner [`Field`]
860    /// directly via [`Field::new`] or [`Field::new_list_field`].
861    pub fn new_large_list(data_type: DataType, nullable: bool) -> Self {
862        DataType::LargeList(Arc::new(Field::new_list_field(data_type, nullable)))
863    }
864
865    /// Create a [`DataType::FixedSizeList`] with elements of the specified type, size
866    /// and nullability, and conventionally named inner [`Field`] (`"item"`).
867    ///
868    /// To specify field level metadata, construct the inner [`Field`]
869    /// directly via [`Field::new`] or [`Field::new_list_field`].
870    pub fn new_fixed_size_list(data_type: DataType, size: i32, nullable: bool) -> Self {
871        DataType::FixedSizeList(Arc::new(Field::new_list_field(data_type, nullable)), size)
872    }
873}
874
875/// The maximum precision for [DataType::Decimal32] values
876pub const DECIMAL32_MAX_PRECISION: u8 = 9;
877
878/// The maximum scale for [DataType::Decimal32] values
879pub const DECIMAL32_MAX_SCALE: i8 = 9;
880
881/// The maximum precision for [DataType::Decimal64] values
882pub const DECIMAL64_MAX_PRECISION: u8 = 18;
883
884/// The maximum scale for [DataType::Decimal64] values
885pub const DECIMAL64_MAX_SCALE: i8 = 18;
886
887/// The maximum precision for [DataType::Decimal128] values
888pub const DECIMAL128_MAX_PRECISION: u8 = 38;
889
890/// The maximum scale for [DataType::Decimal128] values
891pub const DECIMAL128_MAX_SCALE: i8 = 38;
892
893/// The maximum precision for [DataType::Decimal256] values
894pub const DECIMAL256_MAX_PRECISION: u8 = 76;
895
896/// The maximum scale for [DataType::Decimal256] values
897pub const DECIMAL256_MAX_SCALE: i8 = 76;
898
899/// The default scale for [DataType::Decimal32] values
900pub const DECIMAL32_DEFAULT_SCALE: i8 = 2;
901
902/// The default scale for [DataType::Decimal64] values
903pub const DECIMAL64_DEFAULT_SCALE: i8 = 6;
904
905/// The default scale for [DataType::Decimal128] and [DataType::Decimal256]
906/// values
907pub const DECIMAL_DEFAULT_SCALE: i8 = 10;
908
909#[cfg(test)]
910mod tests {
911    use super::*;
912
913    #[test]
914    #[cfg(feature = "serde")]
915    fn serde_struct_type() {
916        use std::collections::HashMap;
917
918        let kv_array = [("k".to_string(), "v".to_string())];
919        let field_metadata: HashMap<String, String> = kv_array.iter().cloned().collect();
920
921        // Non-empty map: should be converted as JSON obj { ... }
922        let first_name =
923            Field::new("first_name", DataType::Utf8, false).with_metadata(field_metadata);
924
925        // Empty map: should be omitted.
926        let last_name =
927            Field::new("last_name", DataType::Utf8, false).with_metadata(HashMap::default());
928
929        let person = DataType::Struct(Fields::from(vec![
930            first_name,
931            last_name,
932            Field::new(
933                "address",
934                DataType::Struct(Fields::from(vec![
935                    Field::new("street", DataType::Utf8, false),
936                    Field::new("zip", DataType::UInt16, false),
937                ])),
938                false,
939            ),
940        ]));
941
942        let serialized = serde_json::to_string(&person).unwrap();
943
944        // NOTE that this is testing the default (derived) serialization format, not the
945        // JSON format specified in metadata.md
946
947        assert_eq!(
948            "{\"Struct\":[\
949             {\"name\":\"first_name\",\"data_type\":\"Utf8\",\"nullable\":false,\"dict_id\":0,\"dict_is_ordered\":false,\"metadata\":{\"k\":\"v\"}},\
950             {\"name\":\"last_name\",\"data_type\":\"Utf8\",\"nullable\":false,\"dict_id\":0,\"dict_is_ordered\":false,\"metadata\":{}},\
951             {\"name\":\"address\",\"data_type\":{\"Struct\":\
952             [{\"name\":\"street\",\"data_type\":\"Utf8\",\"nullable\":false,\"dict_id\":0,\"dict_is_ordered\":false,\"metadata\":{}},\
953             {\"name\":\"zip\",\"data_type\":\"UInt16\",\"nullable\":false,\"dict_id\":0,\"dict_is_ordered\":false,\"metadata\":{}}\
954             ]},\"nullable\":false,\"dict_id\":0,\"dict_is_ordered\":false,\"metadata\":{}}]}",
955            serialized
956        );
957
958        let deserialized = serde_json::from_str(&serialized).unwrap();
959
960        assert_eq!(person, deserialized);
961    }
962
963    #[test]
964    fn test_list_datatype_equality() {
965        // tests that list type equality is checked while ignoring list names
966        let list_a = DataType::List(Arc::new(Field::new_list_field(DataType::Int32, true)));
967        let list_b = DataType::List(Arc::new(Field::new("array", DataType::Int32, true)));
968        let list_c = DataType::List(Arc::new(Field::new_list_field(DataType::Int32, false)));
969        let list_d = DataType::List(Arc::new(Field::new_list_field(DataType::UInt32, true)));
970        assert!(list_a.equals_datatype(&list_b));
971        assert!(!list_a.equals_datatype(&list_c));
972        assert!(!list_b.equals_datatype(&list_c));
973        assert!(!list_a.equals_datatype(&list_d));
974
975        let list_e =
976            DataType::FixedSizeList(Arc::new(Field::new_list_field(list_a.clone(), false)), 3);
977        let list_f =
978            DataType::FixedSizeList(Arc::new(Field::new("array", list_b.clone(), false)), 3);
979        let list_g = DataType::FixedSizeList(
980            Arc::new(Field::new_list_field(DataType::FixedSizeBinary(3), true)),
981            3,
982        );
983        assert!(list_e.equals_datatype(&list_f));
984        assert!(!list_e.equals_datatype(&list_g));
985        assert!(!list_f.equals_datatype(&list_g));
986
987        let list_h = DataType::Struct(Fields::from(vec![Field::new("f1", list_e, true)]));
988        let list_i = DataType::Struct(Fields::from(vec![Field::new("f1", list_f.clone(), true)]));
989        let list_j = DataType::Struct(Fields::from(vec![Field::new("f1", list_f.clone(), false)]));
990        let list_k = DataType::Struct(Fields::from(vec![
991            Field::new("f1", list_f.clone(), false),
992            Field::new("f2", list_g.clone(), false),
993            Field::new("f3", DataType::Utf8, true),
994        ]));
995        let list_l = DataType::Struct(Fields::from(vec![
996            Field::new("ff1", list_f.clone(), false),
997            Field::new("ff2", list_g.clone(), false),
998            Field::new("ff3", DataType::LargeUtf8, true),
999        ]));
1000        let list_m = DataType::Struct(Fields::from(vec![
1001            Field::new("ff1", list_f, false),
1002            Field::new("ff2", list_g, false),
1003            Field::new("ff3", DataType::Utf8, true),
1004        ]));
1005        assert!(list_h.equals_datatype(&list_i));
1006        assert!(!list_h.equals_datatype(&list_j));
1007        assert!(!list_k.equals_datatype(&list_l));
1008        assert!(list_k.equals_datatype(&list_m));
1009
1010        let list_n = DataType::Map(Arc::new(Field::new("f1", list_a.clone(), true)), true);
1011        let list_o = DataType::Map(Arc::new(Field::new("f2", list_b.clone(), true)), true);
1012        let list_p = DataType::Map(Arc::new(Field::new("f2", list_b.clone(), true)), false);
1013        let list_q = DataType::Map(Arc::new(Field::new("f2", list_c.clone(), true)), true);
1014        let list_r = DataType::Map(Arc::new(Field::new("f1", list_a.clone(), false)), true);
1015
1016        assert!(list_n.equals_datatype(&list_o));
1017        assert!(!list_n.equals_datatype(&list_p));
1018        assert!(!list_n.equals_datatype(&list_q));
1019        assert!(!list_n.equals_datatype(&list_r));
1020
1021        let list_s = DataType::Dictionary(Box::new(DataType::UInt8), Box::new(list_a));
1022        let list_t = DataType::Dictionary(Box::new(DataType::UInt8), Box::new(list_b.clone()));
1023        let list_u = DataType::Dictionary(Box::new(DataType::Int8), Box::new(list_b));
1024        let list_v = DataType::Dictionary(Box::new(DataType::UInt8), Box::new(list_c));
1025
1026        assert!(list_s.equals_datatype(&list_t));
1027        assert!(!list_s.equals_datatype(&list_u));
1028        assert!(!list_s.equals_datatype(&list_v));
1029
1030        let union_a = DataType::Union(
1031            UnionFields::try_new(
1032                vec![1, 2],
1033                vec![
1034                    Field::new("f1", DataType::Utf8, false),
1035                    Field::new("f2", DataType::UInt8, false),
1036                ],
1037            )
1038            .unwrap(),
1039            UnionMode::Sparse,
1040        );
1041        let union_b = DataType::Union(
1042            UnionFields::try_new(
1043                vec![1, 2],
1044                vec![
1045                    Field::new("ff1", DataType::Utf8, false),
1046                    Field::new("ff2", DataType::UInt8, false),
1047                ],
1048            )
1049            .unwrap(),
1050            UnionMode::Sparse,
1051        );
1052        let union_c = DataType::Union(
1053            UnionFields::try_new(
1054                vec![2, 1],
1055                vec![
1056                    Field::new("fff2", DataType::UInt8, false),
1057                    Field::new("fff1", DataType::Utf8, false),
1058                ],
1059            )
1060            .unwrap(),
1061            UnionMode::Sparse,
1062        );
1063        let union_d = DataType::Union(
1064            UnionFields::try_new(
1065                vec![2, 1],
1066                vec![
1067                    Field::new("fff1", DataType::Int8, false),
1068                    Field::new("fff2", DataType::UInt8, false),
1069                ],
1070            )
1071            .unwrap(),
1072            UnionMode::Sparse,
1073        );
1074        let union_e = DataType::Union(
1075            UnionFields::try_new(
1076                vec![1, 2],
1077                vec![
1078                    Field::new("f1", DataType::Utf8, true),
1079                    Field::new("f2", DataType::UInt8, false),
1080                ],
1081            )
1082            .unwrap(),
1083            UnionMode::Sparse,
1084        );
1085
1086        assert!(union_a.equals_datatype(&union_b));
1087        assert!(union_a.equals_datatype(&union_c));
1088        assert!(!union_a.equals_datatype(&union_d));
1089        assert!(!union_a.equals_datatype(&union_e));
1090
1091        let list_w = DataType::RunEndEncoded(
1092            Arc::new(Field::new("f1", DataType::Int64, true)),
1093            Arc::new(Field::new("f2", DataType::Utf8, true)),
1094        );
1095        let list_x = DataType::RunEndEncoded(
1096            Arc::new(Field::new("ff1", DataType::Int64, true)),
1097            Arc::new(Field::new("ff2", DataType::Utf8, true)),
1098        );
1099        let list_y = DataType::RunEndEncoded(
1100            Arc::new(Field::new("ff1", DataType::UInt16, true)),
1101            Arc::new(Field::new("ff2", DataType::Utf8, true)),
1102        );
1103        let list_z = DataType::RunEndEncoded(
1104            Arc::new(Field::new("f1", DataType::Int64, false)),
1105            Arc::new(Field::new("f2", DataType::Utf8, true)),
1106        );
1107
1108        assert!(list_w.equals_datatype(&list_x));
1109        assert!(!list_w.equals_datatype(&list_y));
1110        assert!(!list_w.equals_datatype(&list_z));
1111    }
1112
1113    #[test]
1114    fn create_struct_type() {
1115        let _person = DataType::Struct(Fields::from(vec![
1116            Field::new("first_name", DataType::Utf8, false),
1117            Field::new("last_name", DataType::Utf8, false),
1118            Field::new(
1119                "address",
1120                DataType::Struct(Fields::from(vec![
1121                    Field::new("street", DataType::Utf8, false),
1122                    Field::new("zip", DataType::UInt16, false),
1123                ])),
1124                false,
1125            ),
1126        ]));
1127    }
1128
1129    #[test]
1130    fn test_nested() {
1131        let list = DataType::List(Arc::new(Field::new("foo", DataType::Utf8, true)));
1132        let list_view = DataType::ListView(Arc::new(Field::new("foo", DataType::Utf8, true)));
1133        let large_list_view =
1134            DataType::LargeListView(Arc::new(Field::new("foo", DataType::Utf8, true)));
1135
1136        assert!(!DataType::is_nested(&DataType::Boolean));
1137        assert!(!DataType::is_nested(&DataType::Int32));
1138        assert!(!DataType::is_nested(&DataType::Utf8));
1139        assert!(DataType::is_nested(&list));
1140        assert!(DataType::is_nested(&list_view));
1141        assert!(DataType::is_nested(&large_list_view));
1142
1143        assert!(!DataType::is_nested(&DataType::Dictionary(
1144            Box::new(DataType::Int32),
1145            Box::new(DataType::Boolean)
1146        )));
1147        assert!(!DataType::is_nested(&DataType::Dictionary(
1148            Box::new(DataType::Int32),
1149            Box::new(DataType::Int64)
1150        )));
1151        assert!(!DataType::is_nested(&DataType::Dictionary(
1152            Box::new(DataType::Int32),
1153            Box::new(DataType::LargeUtf8)
1154        )));
1155        assert!(DataType::is_nested(&DataType::Dictionary(
1156            Box::new(DataType::Int32),
1157            Box::new(list)
1158        )));
1159    }
1160
1161    #[test]
1162    fn test_integer() {
1163        // is_integer
1164        assert!(DataType::is_integer(&DataType::Int32));
1165        assert!(DataType::is_integer(&DataType::UInt64));
1166        assert!(!DataType::is_integer(&DataType::Float16));
1167
1168        // is_signed_integer
1169        assert!(DataType::is_signed_integer(&DataType::Int32));
1170        assert!(!DataType::is_signed_integer(&DataType::UInt64));
1171        assert!(!DataType::is_signed_integer(&DataType::Float16));
1172
1173        // is_unsigned_integer
1174        assert!(!DataType::is_unsigned_integer(&DataType::Int32));
1175        assert!(DataType::is_unsigned_integer(&DataType::UInt64));
1176        assert!(!DataType::is_unsigned_integer(&DataType::Float16));
1177
1178        // is_dictionary_key_type
1179        assert!(DataType::is_dictionary_key_type(&DataType::Int32));
1180        assert!(DataType::is_dictionary_key_type(&DataType::UInt64));
1181        assert!(!DataType::is_dictionary_key_type(&DataType::Float16));
1182    }
1183
1184    #[test]
1185    fn test_string() {
1186        assert!(DataType::is_string(&DataType::Utf8));
1187        assert!(DataType::is_string(&DataType::LargeUtf8));
1188        assert!(DataType::is_string(&DataType::Utf8View));
1189        assert!(!DataType::is_string(&DataType::Int32));
1190    }
1191
1192    #[test]
1193    fn test_floating() {
1194        assert!(DataType::is_floating(&DataType::Float16));
1195        assert!(!DataType::is_floating(&DataType::Int32));
1196    }
1197
1198    #[test]
1199    fn test_decimal() {
1200        assert!(DataType::is_decimal(&DataType::Decimal32(4, 2)));
1201        assert!(DataType::is_decimal(&DataType::Decimal64(4, 2)));
1202        assert!(DataType::is_decimal(&DataType::Decimal128(4, 2)));
1203        assert!(DataType::is_decimal(&DataType::Decimal256(4, 2)));
1204        assert!(!DataType::is_decimal(&DataType::Float16));
1205    }
1206
1207    #[test]
1208    fn test_datatype_is_null() {
1209        assert!(DataType::is_null(&DataType::Null));
1210        assert!(!DataType::is_null(&DataType::Int32));
1211    }
1212
1213    #[test]
1214    fn test_is_list() {
1215        assert!(DataType::is_list(&DataType::new_list(
1216            DataType::Int16,
1217            true
1218        )));
1219        assert!(DataType::is_list(&DataType::new_large_list(
1220            DataType::Int16,
1221            true
1222        )));
1223        assert!(DataType::is_list(&DataType::new_fixed_size_list(
1224            DataType::Int16,
1225            5,
1226            true
1227        )));
1228        assert!(DataType::is_list(&DataType::ListView(Arc::new(
1229            Field::new("f", DataType::Int16, true)
1230        ))));
1231        assert!(DataType::is_list(&DataType::LargeListView(Arc::new(
1232            Field::new("f", DataType::Int16, true)
1233        ))));
1234        assert!(!DataType::is_list(&DataType::Binary));
1235    }
1236
1237    #[test]
1238    fn test_is_binary() {
1239        assert!(DataType::is_binary(&DataType::Binary));
1240        assert!(DataType::is_binary(&DataType::LargeBinary));
1241        assert!(DataType::is_binary(&DataType::BinaryView));
1242        assert!(!DataType::is_list(&DataType::Utf8View));
1243    }
1244
1245    #[test]
1246    fn size_should_not_regress() {
1247        assert_eq!(std::mem::size_of::<DataType>(), 24);
1248    }
1249
1250    #[test]
1251    #[should_panic(expected = "duplicate type id: 1")]
1252    fn test_union_with_duplicated_type_id() {
1253        let type_ids = vec![1, 1];
1254        let _union = DataType::Union(
1255            UnionFields::try_new(
1256                type_ids,
1257                vec![
1258                    Field::new("f1", DataType::Int32, false),
1259                    Field::new("f2", DataType::Utf8, false),
1260                ],
1261            )
1262            .unwrap(),
1263            UnionMode::Dense,
1264        );
1265    }
1266
1267    #[test]
1268    fn test_try_from_str() {
1269        let data_type: DataType = "Int32".try_into().unwrap();
1270        assert_eq!(data_type, DataType::Int32);
1271    }
1272
1273    #[test]
1274    fn test_from_str() {
1275        let data_type: DataType = "UInt64".parse().unwrap();
1276        assert_eq!(data_type, DataType::UInt64);
1277    }
1278
1279    #[test]
1280    #[cfg_attr(miri, ignore)] // Can't handle the inlined strings of the assert_debug_snapshot macro
1281    fn test_debug_format_field() {
1282        // Make sure the `Debug` formatting of `DataType` is readable and not too long
1283        insta::assert_debug_snapshot!(DataType::new_list(DataType::Int8, false), @r"
1284        List(
1285            Field {
1286                data_type: Int8,
1287            },
1288        )
1289        ");
1290    }
1291}