Struct Predicate 

pub struct Predicate<D, Scope> { /* private fields */ }

A condition whose scope requirement has already been discharged, so a runtime-length collection of them can be built and passed around. An Expr carries the tables it references in its type, which is what makes vec![users_cond, orders_cond] fail to unify; predicate trades that tag for a proof against one concrete scope.

Implementations

impl<D, Scope> Predicate<D, Scope>

pub fn any_of(preds: impl IntoIterator<Item = Predicate<D, Scope>>) -> Self

True when any of them is. expr::any_of combines conditions that reference the same tables; this one combines conditions whose scope requirement is already discharged, which is what lets a search form OR together conditions from different tables.

pub fn all_of(preds: impl IntoIterator<Item = Predicate<D, Scope>>) -> Self

True when all of them are — the AND to any_of’s OR, so a group of them can be nested inside one.

Trait Implementations

impl<D, Scope> Clone for Predicate<D, Scope>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<D, Scope> Condition<D, Scope, ()> for Predicate<D, Scope>