Enum SccFixpointError 

pub enum SccFixpointError {
    RuleHeadPredicateMismatch {
        group_key: String,
        rule_index: usize,
        observed: String,
    },
    HeadArityMismatch {
        predicate: String,
        rule_index: usize,
        observed_arity: usize,
        expected_arity: usize,
    },
    InconsistentHeadValueTypes {
        predicate: String,
        column: usize,
        expected: ScalarType,
        got: String,
    },
    PredicateInBaseRelations {
        name: String,
    },
    RuleEval {
        predicate: String,
        rule_index: usize,
        source: RefEvalError,
    },
    MaxIterationsExceeded {
        limit: usize,
        predicate_count: usize,
        total_observed_rows: usize,
    },
    SchemaIndeterminable {
        predicate: String,
    },
    InvalidMaxIterations,
}

Errors surfaced by evaluate_scc_fixpoint.

Variants

RuleHeadPredicateMismatch

A rule grouped under predicate key heads a different predicate. The grouping invariant — every rule’s head predicate equals its BTreeMap key — is checked at function entry.

Fields

group_key: String

BTreeMap key under which the rule was grouped.

rule_index: usize

Index of the rule within that group.

observed: String

Head predicate observed on the rule.

HeadArityMismatch

Two rules grouped under the same predicate disagree on head arity.

Fields

predicate: String

Predicate name.

rule_index: usize

Index of the offending rule within its group.

observed_arity: usize

Head arity observed on this rule.

expected_arity: usize

Head arity established by the first non-empty-head rule in the same group.

InconsistentHeadValueTypes

A predicate’s rules produced rows whose RefValue variants disagree across iterations or across rules within an iteration. Detected by validating each newly produced row’s variant tuple against the predicate’s frozen schema before unioning.

Fields

predicate: String

Predicate name.

column: usize

Column index where the mismatch was first observed.

expected: ScalarType

Schema-frozen scalar type at that column.

got: String

String description of the offending value.

PredicateInBaseRelations

target_predicate was already present in base_relations. SCC predicates are constructed by the fixpoint; allowing base_relations to seed any of them would silently shadow the caller’s seed.

Fields

name: String

The SCC predicate name as supplied.

RuleEval

A rule failed evaluation. Wraps the per-rule error with (predicate, rule_index) so the caller can pinpoint which rule of which group failed.

Fields

predicate: String

Predicate group of the offending rule.

rule_index: usize

Index within that group.

source: RefEvalError

The wrapped per-rule error.

MaxIterationsExceeded

The SCC fixpoint did not converge within FixpointConfig::max_iterations.

Fields

limit: usize

The configured cap.

predicate_count: usize

Number of predicates in the SCC.

total_observed_rows: usize

Total derived rows summed across all SCC predicates at the cap.

SchemaIndeterminable

At least one predicate had no rules with a non-empty head, so its arity could not be inferred.

Fields

predicate: String

Predicate name whose arity could not be inferred.

InvalidMaxIterations

max_iterations was zero. Must be ≥ 1.

Trait Implementations

impl Clone for SccFixpointError

fn clone(&self) -> SccFixpointError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SccFixpointError

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

Formats the value using the given formatter.

impl PartialEq for SccFixpointError

fn eq(&self, other: &SccFixpointError) -> 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 StructuralPartialEq for SccFixpointError