inputs

Module to check that programs do not contain inputs in their rule heads.

HeadPredicateCollector

Bases: Transformer

Class to collect the head predicates of a normalized program.

__init__() -> None

Initialize an empty set of head predicates.

visit_Rule(node: AST) -> AST

Collect the head predicate of a rule.

Handles literal heads and (normalized) choice heads; empty heads (constraints) contribute no predicate.

check_inputs_not_in_heads(left: list[AST], right: list[AST], inputs: set[Predicate]) -> None

Check that neither program contains an input predicate in a rule head.

Raises an AnthemCXError (causing anthem-cx to exit) if an input predicate occurs in a head. The programs are expected to be normalized.

collect_head_predicates(program: list[AST]) -> set[Predicate]

Collect all predicates occurring in the rule heads of a normalized program.

inputs_in_heads(program: list[AST], inputs: set[Predicate]) -> set[Predicate]

Get the input predicates occurring in the rule heads of a program.

Returns the set of input predicates that occur in a head (empty if the program is valid). The program is expected to be normalized.