arrowFormatOf

fnstring arrowFormatOf(DataType dtype) @safe

Maps a flat DataType to its Arrow C Data Interface format string (verified against pyarrow 21.0.0's _export_to_c): STRING maps to "U" (large_string — our offsets are int64), DATETIME to "tsn:" (timestamp[ns], no timezone), TIME to "ttn" (time64[ns]).

Parameters

dtype the dtype to map

Returns

the format string.

Throws

DataFrameException for the rich kinds (their schema half

arrives with the rich-interchange tier).