/** Partially evaluate the right-hand side and the conditions of a specified rule. */
private static Rule evaluateRule(Rule rule, TermContext termContext) {
try {
// TODO(AndreiS): some evaluation is required in the LHS as well
// TODO(YilongL): cannot simply uncomment the following code because it
// may evaluate the LHS using the rule itself
// Term leftHandSide = rule.leftHandSide().evaluate(termContext);
Rule origRule = rule;
Term rightHandSide = rule.rightHandSide().evaluate(termContext);
List<Term> requires = new ArrayList<>();
for (Term term : rule.requires()) {
requires.add(term.evaluate(termContext));
}
List<Term> ensures = new ArrayList<>();
for (Term term : rule.ensures()) {
ensures.add(term.evaluate(termContext));
}
ConjunctiveFormula lookups = ConjunctiveFormula.of(termContext);
for (Equality equality : rule.lookups().equalities()) {
lookups =
lookups.add(
equality.leftHandSide().evaluate(termContext),
equality.rightHandSide().evaluate(termContext));
}
Map<CellLabel, Term> rhsOfWriteCell = null;
if (rule.isCompiledForFastRewriting()) {
rhsOfWriteCell = new HashMap<>();
for (Map.Entry<CellLabel, Term> entry : rule.rhsOfWriteCell().entrySet()) {
rhsOfWriteCell.put(entry.getKey(), entry.getValue().evaluate(termContext));
}
}
Rule newRule =
new Rule(
rule.label(),
rule.leftHandSide(),
rightHandSide,
requires,
ensures,
rule.freshConstants(),
rule.freshVariables(),
lookups,
rule.isCompiledForFastRewriting(),
rule.lhsOfReadCell(),
rhsOfWriteCell,
rule.cellsToCopy(),
rule.matchingInstructions(),
rule,
termContext);
return newRule.equals(rule) ? origRule : newRule;
} catch (KEMException e) {
e.exception.addTraceFrame(
"while compiling rule at location " + rule.getSource() + rule.getLocation());
throw e;
}
}
/** Partially evaluate the right-hand side and the conditions for each rule. */
private static Definition evaluateDefinition(TermContext termContext) {
Definition definition = termContext.global().getDefinition();
/* replace the unevaluated rules defining functions with their partially evaluated counterparts */
ArrayList<Rule> partiallyEvaluatedRules = new ArrayList<>();
/* iterate until a fixpoint is reached, because the evaluation with functions uses Term#substituteAndEvalaute */
while (true) {
boolean change = false;
partiallyEvaluatedRules.clear();
for (Rule rule :
Iterables.concat(
definition.functionRules().values(), definition.anywhereRules().values())) {
Rule freshRule = rule.getFreshRule(termContext);
Rule evaluatedRule = evaluateRule(freshRule, termContext);
partiallyEvaluatedRules.add(evaluatedRule);
if (!evaluatedRule.equals(freshRule)) {
change = true;
}
}
if (!change) {
break;
}
definition.functionRules().clear();
definition.anywhereRules().clear();
definition.addRuleCollection(partiallyEvaluatedRules);
}
/* replace the unevaluated rules and macros with their partially evaluated counterparts */
partiallyEvaluatedRules.clear();
Iterable<Rule> rules =
Iterables.concat(
definition.rules(),
definition.macros(),
definition.patternRules().values(),
definition.patternFoldingRules());
for (Rule rule : rules) {
partiallyEvaluatedRules.add(evaluateRule(rule, termContext));
}
definition.rules().clear();
definition.macros().clear();
definition.patternRules().clear();
definition.patternFoldingRules().clear();
definition.addRuleCollection(partiallyEvaluatedRules);
return definition;
}