Struct JoinKeySet 

pub struct JoinKeySet {
    inner: IndexSet<(Expr, Expr)>,
}

Tracks a set of equality Join keys

A join key is an expression that is used to join two tables via an equality predicate such as a.x = b.y

This struct models a.x + 5 = b.y AND a.z = b.z as two join keys

1. (a.x + 5, b.y)
2. (a.z, b.z)

Important properties:

1. Retains insert order
2. Can quickly look up if a pair of expressions are in the set.

Fields

inner: IndexSet<(Expr, Expr)>

Implementations

impl JoinKeySet

pub fn new() -> Self

Create a new empty set

pub fn contains(&self, left: &Expr, right: &Expr) -> bool

Return true if the set contains a join pair where left = right or right = left

pub fn insert(&mut self, left: &Expr, right: &Expr) -> bool

Insert the join key (left = right) into the set if join pair (right = left) is not already in the set

returns true if the pair was inserted

pub fn insert_owned(&mut self, left: Expr, right: Expr) -> bool

Same as Self::insert but avoids cloning expression if they are owned

pub fn insert_all<'a>( &mut self, iter: impl IntoIterator<Item = &'a (Expr, Expr)>, ) -> bool

Inserts potentially many join keys into the set, copying only when necessary

returns true if any of the pairs were inserted

pub fn insert_all_owned( &mut self, iter: impl IntoIterator<Item = (Expr, Expr)>, ) -> bool

Same as Self::insert_all but avoids cloning expressions if they are already owned

returns true if any of the pairs were inserted

pub fn insert_intersection(&mut self, s1: &JoinKeySet, s2: &JoinKeySet)

Inserts any join keys that are common to both s1 and s2 into self

pub fn is_empty(&self) -> bool

returns true if this set is empty

pub fn iter(&self) -> impl Iterator<Item = (&Expr, &Expr)>

Return an iterator over the join keys in this set

Trait Implementations

impl Debug for JoinKeySet

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

Formats the value using the given formatter.