Struct Row

pub struct Row<T>(/* private fields */);

A cheaply cloneable, insertion-ordered map from FieldName to T.

Also stores a “label” for each entry, which may not be the same as the FieldName in the case that the FieldName is a UUID.

This is called “row” because it’s a short name, and it corresponds to the idea of a row in a database, which is a map from fields to values.

Create this using the FromIterator implementation.

Implementations

impl<T> Row<T>

pub fn get(&self, name: FieldName) -> Option<&T>

Lookup the field name if it exists.

Also see the Index implementation, which just unwraps this.

pub fn iter(&self) -> impl Iterator<Item = (&FieldName, &(LabelSegment, T))>

Iterate through the fields in insertion order.

pub fn len(&self) -> usize

Return the number of fields.

pub fn is_empty(&self) -> bool

Return whether the row is empty (Clippy wants this).

pub fn has(&self, field_name: FieldName) -> bool

Return whether the row contains the given field

pub fn empty() -> Self

Produce the empty row.

pub fn map<S>(&self, f: impl Fn(&T) -> S) -> Row<S>

Map a function to produce a new row.

impl<T: Clone> Row<T>

pub fn insert(self, field: FieldName, label: LabelSegment, value: T) -> Self

Insert a new field

Uses Rc::make_mut to mutate in place if there are no other references to self, otherwise performs a clone.

Trait Implementations

impl<T: Clone> Clone for Row<T>

fn clone(&self) -> Row<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T> From<IndexMap<NameSegment, (LabelSegment, T)>> for Row<T>

fn from(value: IndexMap<FieldName, (LabelSegment, T)>) -> Self

Converts to this type from the input type.

impl<T> FromIterator<(NameSegment, (LabelSegment, T))> for Row<T>

fn from_iter<I>(iter: I) -> Self

where I: IntoIterator<Item = (FieldName, (LabelSegment, T))>,

Creates a value from an iterator.

impl<T> Index<NameSegment> for Row<T>

type Output = T

The returned type after indexing.

fn index(&self, index: FieldName) -> &Self::Output

Performs the indexing (container[index]) operation.

impl<T: PartialEq> PartialEq for Row<T>

fn eq(&self, other: &Row<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: Eq> Eq for Row<T>

impl<T> StructuralPartialEq for Row<T>