Struct Program 

pub struct Program {
    pub rules: Vec<Rule>,
}

Datalog program as an ordered set of rules.

Fields

rules: Vec<Rule>

Program rules.

Implementations

impl Program

pub fn validate(&self) -> Result<(), ProgramValidationError>

Validate all rules in the program for safety and stratifiability.

Runs two checks:

1. Safety — every rule must be range-restricted; head variables and variables inside negated body literals must also appear in some positive body literal.
2. Stratifiability — the predicate dependency graph must have no cycle that includes a negation edge (see Program::stratify).

Errors

Returns ProgramValidationError::UnsafeRule on a safety failure, ProgramValidationError::UnsafeNegation when a negated body literal references a variable that no positive literal binds, or ProgramValidationError::UnstratifiableNegation when the program contains a recursive cycle through negation.

pub fn validate_with_equality_mode( &self, equality_mode: EqualityMode, ) -> Result<(), ProgramValidationError>

Validate the program under a specified equality-reasoning mode (extension).

Runs the same safety / stratification / triple-term-nesting checks as Self::validate and additionally rejects negation and aggregation when equality_mode == EqualityMode::SameAs. The two features interact non-monotonically with owl:sameAs rewriting; see EqualityMode for the semantic rationale.

Errors

Returns the same errors as Self::validate plus ProgramValidationError::NegationUnderEqualityMode or ProgramValidationError::AggregationUnderEqualityMode when the corresponding feature is used under EqualityMode::SameAs.

pub fn stratify(&self) -> Result<Stratification, ProgramValidationError>

Compute the program’s stratification.

Builds the predicate dependency graph (edges from each body predicate to the head predicate, tagged with polarity), collapses strongly connected components, checks that no SCC contains an internal negation edge, and assigns each predicate to a stratum such that every negation edge goes from a lower stratum to a strictly higher one.

Errors

Returns ProgramValidationError::UnstratifiableNegation when a cycle in the dependency graph contains a negation edge.

Trait Implementations

impl Clone for Program

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Program

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

Formats the value using the given formatter.

impl Default for Program

fn default() -> Self

Returns the “default value” for a type.

impl Eq for Program

impl PartialEq for Program

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Program