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Code Issues 15 Releases 21 Activity

Added support for completion of integrity constraints.

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This commit is contained in:
Patrick Lühne 2017-04-08 18:25:59 +02:00
parent a716da4af1
commit 8210adea7c
Signed by: patrick
GPG Key ID: 05F3611E97A70ABF
3 changed files with 53 additions and 6 deletions
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1
include/anthem/ASTUtils.h
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@ -31,6 +31,7 @@ class VariableStack
////////////////////////////////////////////////////////////////////////////////////////////////////
std::vector<ast::Variable> collectFreeVariables(const ast::Formula &formula);
std::vector<ast::Variable> collectFreeVariables(const ast::Formula &formula, ast::VariableStack &variableStack);
////////////////////////////////////////////////////////////////////////////////////////////////////

8
src/anthem/ASTUtils.cpp
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@ -175,6 +175,14 @@ struct CollectFreeVariablesVisitor
////////////////////////////////////////////////////////////////////////////////////////////////////
std::vector<ast::Variable> collectFreeVariables(const ast::Formula &formula)
{
ast::VariableStack variableStack;
return collectFreeVariables(formula, variableStack);
}
////////////////////////////////////////////////////////////////////////////////////////////////////
std::vector<ast::Variable> collectFreeVariables(const ast::Formula &formula, ast::VariableStack &variableStack)
{
std::vector<ast::Variable> freeVariables;

48
src/anthem/Completion.cpp
View File

@ -32,7 +32,10 @@ void completePredicate(const ast::Predicate &predicate, std::vector<ast::Formula
auto &formula = formulas[i];
assert(formula.is<ast::Implies>());
auto &implies = formula.get<ast::Implies>();
assert(implies.consequent.is<ast::Predicate>());
if (!implies.consequent.is<ast::Predicate>())
continue;
auto &otherPredicate = implies.consequent.get<ast::Predicate>();
if (predicate.arity() != otherPredicate.arity() || predicate.name != otherPredicate.name)
@ -60,7 +63,13 @@ void completePredicate(const ast::Predicate &predicate, std::vector<ast::Formula
auto &formula = formulas[i];
assert(formula.is<ast::Implies>());
auto &implies = formula.get<ast::Implies>();
assert(implies.consequent.is<ast::Predicate>());
if (!implies.consequent.is<ast::Predicate>())
{
i++;
continue;
}
auto &otherPredicate = implies.consequent.get<ast::Predicate>();
if (predicate.arity() != otherPredicate.arity() || predicate.name != otherPredicate.name)
@ -107,6 +116,30 @@ void completePredicate(const ast::Predicate &predicate, std::vector<ast::Formula
////////////////////////////////////////////////////////////////////////////////////////////////////
void completeBoolean(ast::Formula &formula)
{
assert(formula.is<ast::Implies>());
auto &implies = formula.get<ast::Implies>();
assert(implies.consequent.is<ast::Boolean>());
auto &boolean = implies.consequent.get<ast::Boolean>();
auto variables = ast::collectFreeVariables(implies.antecedent);
auto argument = (boolean.value == true)
? std::move(implies.antecedent)
: ast::Formula::make<ast::Not>(std::move(implies.antecedent));
if (variables.empty())
{
formula = std::move(argument);
return;
}
formula = ast::Formula::make<ast::ForAll>(std::move(variables), std::move(argument));
}
////////////////////////////////////////////////////////////////////////////////////////////////////
void complete(std::vector<ast::Formula> &formulas)
{
for (const auto &formula : formulas)
@ -116,18 +149,23 @@ void complete(std::vector<ast::Formula> &formulas)
auto &implies = formula.get<ast::Implies>();
if (!implies.consequent.is<ast::Predicate>())
throw std::runtime_error("cannot perform completion, only single predicates supported as formula consequent currently");
if (!implies.consequent.is<ast::Predicate>() && !implies.consequent.is<ast::Boolean>())
throw std::runtime_error("cannot perform completion, only single predicates and Booleans supported as formula consequent currently");
}
for (std::size_t i = 0; i < formulas.size(); i++)
{
auto &formula = formulas[i];
auto &implies = formula.get<ast::Implies>();
auto &predicate = implies.consequent.get<ast::Predicate>();
if (implies.consequent.is<ast::Predicate>())
{
auto &predicate = implies.consequent.get<ast::Predicate>();
completePredicate(predicate, formulas, i);
}
else if (implies.consequent.is<ast::Boolean>())
completeBoolean(formula);
}
}
////////////////////////////////////////////////////////////////////////////////////////////////////