Struct ProjectedField 

pub struct ProjectedField { /* private fields */ }

One field of a Projection: its column id, its physical type and what its absence means.

Implementations

impl ProjectedField

pub fn new(column_id: u16, type_tag: TypeTag, absent: Absent) -> Result<Self>

A field with a declared type and absence.

Errors

Returns an error if absent is a default that does not fit type_tag (a fixed-width type takes exactly its width), if type_tag is a fixed width of zero, which no column may carry, or if column_id names an intrinsic column, whose type and presence are fixed.

pub fn by_id(column_id: u16) -> Self

A field projected by id alone: an intrinsic column, or a value column whose type is whatever the segments store. Its null cells stay null; a segment written without the column is an error, since nothing declares the type a stand-in column would need.

pub fn column_id(&self) -> u16

The field’s column id.

pub fn type_tag(&self) -> Option<TypeTag>

The field’s declared type, or None when it was projected by id alone.

pub fn absent(&self) -> &Absent

What the field reads as where a row does not have it.

Trait Implementations

impl Clone for ProjectedField

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ProjectedField

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for ProjectedField

impl PartialEq for ProjectedField

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for ProjectedField