Struct cbor_tag_index::DnfQuery

pub struct DnfQuery<T> { /* fields omitted */ }

A compact representation of a seq of tag sets, to be used as a DNF query.

The internal repesentation is using a bitmap for efficiency. So assuming string tags, e.g. (“a” & “b”) | (“b” & “c”) | (“d”) would be encoded as

{
  tags: ["a", "b", "c", "d"],
  sets: [
    b0011,
    b0110,
    b1000,
  ]
}

so the possibly large tags have to be stored only once, and operations can work on bit sets.

Implementations

impl<T> DnfQuery<T>

pub fn empty() -> Self

An empty dnf query which matches nothing

pub fn is_empty(&self) -> bool

Are we an empty dnf query which matches nothing?

pub fn all() -> Self

a dnf query containing an empty set, which matches everything

pub fn is_all(&self) -> bool

Are we a dnf query containing an empty set, which matches everything?

pub fn terms(&self) -> impl Iterator<Item = impl Iterator<Item = &T>>

get back the terms making up the dnf query

Note that there is no guarantee that there will be the same number of terms or that tags in each term will be ordered in the same way.

pub fn len(&self) -> usize

impl<T: Tag> DnfQuery<T>

pub fn new(
    terms: impl IntoIterator<Item = impl IntoIterator<Item = T>>
) -> Result<Self>

Build a new DnfQuery from a sequence of terms, where each term contains a sequence of tags.

pub fn matching(&self, index: &TagIndex<T>) -> Vec<bool>

Helper method to return the matching indexes, mostly for tests

pub fn set_matching(&self, index: &TagIndex<T>, matches: &mut [bool])

given a bitmap of matches, corresponding to the events in the index, set those bytes to false that do not match.

Trait Implementations

impl<T: Clone> Clone for DnfQuery<T>

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

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for DnfQuery<T>

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

Formats the value using the given formatter.

impl<T: DagCbor> Decode<DagCborCodec> for DnfQuery<T>

fn decode<R: Read + Seek>(c: DagCborCodec, r: &mut R) -> Result<Self>

Decode from an impl Read.

impl<T: Default> Default for DnfQuery<T>

fn default() -> DnfQuery<T>

Returns the “default value” for a type.

impl<T: Display> Display for DnfQuery<T>

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

Formats the value using the given formatter.

impl<T: DagCbor> Encode<DagCborCodec> for DnfQuery<T>

fn encode<W: Write>(&self, c: DagCborCodec, w: &mut W) -> Result<()>

Encodes into a impl Write.

impl<T: PartialEq> PartialEq<DnfQuery<T>> for DnfQuery<T>

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

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &DnfQuery<T>) -> bool

This method tests for !=.

impl<T: Eq> Eq for DnfQuery<T>

impl<T> StructuralEq for DnfQuery<T>

impl<T> StructuralPartialEq for DnfQuery<T>