Struct Grouping 

pub struct Grouping {
    pub keys: Vec<String>,
    pub by: Option<Grain>,
}

What a view sorts records by — MoReq2010’s classification.

One shape, not a set of blessed kinds: an ordered chain of field keys, and an optional grain to cut the chosen value at. See the module docs for why there is no date variant.

Fields

keys: Vec<String>

The field keys to read, in order — the first that carries a value wins, and supplies all of that view’s group keys for the document. Guaranteed non-empty by ViewSpec::parse.

by: Option<Grain>

The grain the chosen value is cut at, or None to group on the value itself.

Implementations

impl Grouping

pub fn field(key: impl Into<String>) -> Self

A view grouped on one field’s raw values.

pub fn keys_of(&self, meta: &Value) -> Vec<String>

The group keys meta falls under — empty when no field in the chain carries a usable value, which is the ungrouped bucket.

A sequence-valued field yields one key per element, so a letter about two people appears under both. That is the whole point of a view: the same document reached several ways, with retrieval decoupled from the single containment spine.

The chain stops at the first key that is present and non-empty, and its values are used even if the grain rejects all of them. Falling through to created because date_of_document held something unparseable would silently file the document under a date it does not claim; leaving it ungrouped shows the bad value instead.

Trait Implementations

impl Clone for Grouping

fn clone(&self) -> Grouping

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Grouping

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

Formats the value using the given formatter.

impl Eq for Grouping

impl PartialEq for Grouping

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Grouping