flechette

Flechette API Reference

Schema Object

A schema describes the contents of a table, including all column names and types as well as any associated metadata. A schema is represented as a standard JavaScript object with the following properties:

version (number): A number indicating the Arrow version of the data, corresponding to the properties of the top-level Version object. When creating new tables, Flechette uses Version.V5.
endianness (number): The binary endianness (byte order) of the Arrow data. Be default, Flechette assumes the value Endianness.Little.
fields (Field[]): An array of field specifications. See the field documentation for more details.
metadata (Map<string, string>): Custom schema-level metadata annotations.

Field Object

A field describes the name, data type, and metadata for a collection of data values. A field may correspond to either a top-level column or nested data such as the content of a list, struct, or union type. A field is represented as a standard JavaScript object with the following properties:

name (string): The field name.
type (DataType): The field data type. See the Data Types documentation for more.
nullable (boolean): Metadata flag indicating if the field values may be set to null.
metadata (Map<string, string>): Custom field-level metadata annotations.

# field(name, type[, nullable, metadata])

Create a new field instance for use in a schema or type definition. A field represents a field name, data type, and additional metadata. Fields are used to represent child types within nested types like List, Struct, and Union.

name (string): The field name.
type (DataType): The field data type.
nullable (boolean): Flag indicating if the field is nullable (default true).
metadata (Map<string,string>): Custom field metadata annotations (default null).

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