Trait StatsRewriteRule 

pub trait StatsRewriteRule:
    Debug
    + Send
    + Sync
    + 'static {
    // Required method
    fn scalar_fn_id(&self) -> ScalarFnId;

    // Provided methods
    fn falsify(
        &self,
        expr: &Expression,
        ctx: &StatsRewriteCtx<'_>,
    ) -> VortexResult<Option<Expression>> { ... }
    fn satisfy(
        &self,
        expr: &Expression,
        ctx: &StatsRewriteCtx<'_>,
    ) -> VortexResult<Option<Expression>> { ... }
}

A plugin-provided rule for predicates whose root scalar function matches this rule.

Rules do not produce expressions equivalent to expr. They produce optional sufficient conditions over stats for the current scope:

• a falsifier evaluating to true proves that expr is false for every row in the scope;
• a satisfier evaluating to true proves that expr is true for every row in the scope.

Returning None means this rule cannot prove anything for the expression. A returned proof expression that evaluates to false or null is also inconclusive.

Multiple rules may be registered for the same scalar function. Their proofs are combined with OR, so every proof returned by an individual rule must be sound on its own.

expr is the full predicate expression whose root scalar function id is Self::scalar_fn_id. Use StatsRewriteCtx to resolve dtypes and recursively rewrite child predicates.

Required Methods

fn scalar_fn_id(&self) -> ScalarFnId

Returns the scalar function id handled by this rule.

Provided Methods

fn falsify( &self, expr: &Expression, ctx: &StatsRewriteCtx<'_>, ) -> VortexResult<Option<Expression>>

Returns a stats-backed proof that expr is false for the current scope.

If the returned expression evaluates to true against the scope’s stats, then expr is guaranteed to be false for every row in that scope. A returned proof expression that evaluates to false or null is inconclusive.

Returns Ok(None) when this rule cannot construct a sound falsity proof for expr.

fn satisfy( &self, expr: &Expression, ctx: &StatsRewriteCtx<'_>, ) -> VortexResult<Option<Expression>>

Returns a stats-backed proof that expr is true for the current scope.

If the returned expression evaluates to true against the scope’s stats, then expr is guaranteed to be true for every row in that scope. A returned proof expression that evaluates to false or null is inconclusive.

This is not the complement of Self::falsify; both methods are one-way proofs and may be implemented independently.

Returns Ok(None) when this rule cannot construct a sound truth proof for expr.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors