DictionaryType: DictionaryType class

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DictionaryType class

Description

DictionaryType is a FixedWidthType that represents dictionary-encoded data. Dictionary encoding stores unique values in a dictionary and uses integer-type indices to reference them, which can be more memory-efficient for data with many repeated values.

R6 Methods

• ⁠$ToString()⁠: Return a string representation of the dictionary type

• ⁠$code(namespace = FALSE)⁠: Return R code to create this dictionary type

Active bindings

• ⁠$index_type⁠: The DataType for the dictionary indices (must be an integer type, signed or unsigned)

• ⁠$value_type⁠: The DataType for the dictionary values

• ⁠$name⁠: The name of the type.

• ⁠$ordered⁠: Whether the dictionary is ordered.

Factory

DictionaryType$create() takes the following arguments:

• index_type: A DataType for the indices (default int32())

• value_type: A DataType for the values (default utf8())

• ordered: Is this an ordered dictionary (default FALSE)?

arrow documentation built on Jan. 23, 2026, 5:07 p.m.