ddn.columnar.structs

The struct-column layer of ddn.df (ADR-2026-10-23-13/-14): named field chunks in children[i] with parent validity marking whole-struct nulls, distinct from a valid struct of null fields. Field order is pinned by the metadata's fields; duplicate names are construction errors.

Copyright

License

BSD-3-Clause

struct StructBuilder

fn combineStructValidity enforceFlatField fieldIndexOf fieldWindows structField structRechunk structSeries structTake validateStructChunk

Types 1

structStructBuilder

Builds one STRUCT chunk from field chunks: each field's chunk must carry exactly length elements (validated); the parent's validity marks whole-struct nulls; field values under a null parent are never read.

Fields

private string[] _fields

private ArrayData[] _fieldChunks

private ulong[] _validity

private size_t _length

private bool _anyNull

private bool _sealed

Methods

void field(size_t i, ArrayData chunk) @safe pure nothrowSets the field chunk for field `i` (must carry `length` elements; validated at finish).

void markNull(size_t i) @safe pure nothrowMarks row `i` as a null struct (the whole row).

void length(size_t n) @safe pure nothrowMarks rows `0 .. n` as the struct count.

private void ensureValidity(size_t i) @safe pure nothrow

ArrayData finish() @safeSeals the STRUCT chunk.

private size_t countValid() @safe pure nothrow

Constructors

this(string[] fields)Params: fields = the ordered field names (duplicates rejected at finish)

Functions 9

fnvoid validateStructChunk(const ArrayData chunk) @safeValidates a STRUCT chunk: field count matches the metadata, field chunks carry the parent's length, no duplicate names.

fnSeries structField(Series s, string name) @trustedExtracts one field as its own Series (the field chunks gathered into one Series of the field's dtype).

private fn

ArrayData combineStructValidity(const  ArrayData parent,
       const  ArrayData win)

@trusted pure nothrow

private fnsize_t fieldIndexOf(DataType dtype, string name) @safe pure nothrow

Series structSeries(string name,  string[]  fieldNames,
       Series[]  fields)

@trustedBuilds a STRUCT Series from its field Series (equal lengths, ordered names).

private fnvoid enforceFlatField(string fieldName, DataType dtype) @safe

private fnArrayData[] fieldWindows(const ArrayData[] chunks, size_t f)

ArrayData structTake(const  ArrayData[]  chunks,
       const  size_t[]  chunkStarts,  const(size_t)[]  indices,
       DataType dtype)

@trusted

fnArrayData structRechunk(const ArrayData[] chunks, DataType dtype) @trusted