anthem/include/anthem/Head.h

323 lines
12 KiB
C++

#ifndef __ANTHEM__HEAD_H
#define __ANTHEM__HEAD_H
#include <algorithm>
#include <anthem/AST.h>
#include <anthem/Utils.h>
#include <anthem/output/Formatting.h>
namespace anthem
{
////////////////////////////////////////////////////////////////////////////////////////////////////
//
// Head
//
////////////////////////////////////////////////////////////////////////////////////////////////////
struct TermCollectFunctionTermsVisitor
{
void visit(const Clingo::Symbol &, const Clingo::AST::Term &term, Context &context)
{
throwErrorAtLocation(term.location, "“symbol” terms not allowed, function expected", context);
}
void visit(const Clingo::AST::Variable &, const Clingo::AST::Term &term, Context &context)
{
throwErrorAtLocation(term.location, "“variable” terms currently unsupported, function expected", context);
}
void visit(const Clingo::AST::UnaryOperation &, const Clingo::AST::Term &term, Context &context)
{
throwErrorAtLocation(term.location, "“unary operation” terms currently unsupported, function expected", context);
}
void visit(const Clingo::AST::BinaryOperation &, const Clingo::AST::Term &term, Context &context)
{
throwErrorAtLocation(term.location, "“binary operation” terms currently unsupported, function expected", context);
}
void visit(const Clingo::AST::Interval &, const Clingo::AST::Term &term, Context &context)
{
throwErrorAtLocation(term.location, "“interval” terms currently unsupported, function expected", context);
}
void visit(const Clingo::AST::Function &function, const Clingo::AST::Term &term, Context &context)
{
if (function.external)
throwErrorAtLocation(term.location, "external functions currently unsupported", context);
context.headTerms.reserve(context.headTerms.size() + function.arguments.size());
for (const auto &argument : function.arguments)
context.headTerms.emplace_back(&argument);
}
void visit(const Clingo::AST::Pool &, const Clingo::AST::Term &term, Context &context)
{
throwErrorAtLocation(term.location, "“pool” terms currently unsupported, function expected", context);
}
};
////////////////////////////////////////////////////////////////////////////////////////////////////
struct LiteralCollectFunctionTermsVisitor
{
void visit(const Clingo::AST::Boolean &, const Clingo::AST::Literal &, Context &)
{
}
void visit(const Clingo::AST::Term &term, const Clingo::AST::Literal &, Context &context)
{
term.data.accept(TermCollectFunctionTermsVisitor(), term, context);
}
void visit(const Clingo::AST::Comparison &, const Clingo::AST::Literal &literal, Context &context)
{
throwErrorAtLocation(literal.location, "only disjunctions of literals allowed as head literals", context);
}
void visit(const Clingo::AST::CSPLiteral &, const Clingo::AST::Literal &literal, Context &context)
{
throwErrorAtLocation(literal.location, "only disjunctions of literals allowed as head literals", context);
}
};
////////////////////////////////////////////////////////////////////////////////////////////////////
// TODO: rename, because not only terms are collected anymore
struct HeadLiteralCollectFunctionTermsVisitor
{
void visit(const Clingo::AST::Literal &literal, const Clingo::AST::HeadLiteral &, Context &context)
{
context.numberOfHeadLiterals = 1;
literal.data.accept(LiteralCollectFunctionTermsVisitor(), literal, context);
}
void visit(const Clingo::AST::Disjunction &disjunction, const Clingo::AST::HeadLiteral &headLiteral, Context &context)
{
context.numberOfHeadLiterals = disjunction.elements.size();
for (const auto &conditionalLiteral : disjunction.elements)
{
if (!conditionalLiteral.condition.empty())
throwErrorAtLocation(headLiteral.location, "conditional head literals currently unsupported", context);
conditionalLiteral.literal.data.accept(LiteralCollectFunctionTermsVisitor(), conditionalLiteral.literal, context);
}
}
void visit(const Clingo::AST::Aggregate &aggregate, const Clingo::AST::HeadLiteral &headLiteral, Context &context)
{
context.isChoiceRule = true;
context.numberOfHeadLiterals = aggregate.elements.size();
if (aggregate.left_guard || aggregate.right_guard)
throwErrorAtLocation(headLiteral.location, "aggregates with left or right guards not allowed", context);
for (const auto &conditionalLiteral : aggregate.elements)
{
if (!conditionalLiteral.condition.empty())
throwErrorAtLocation(headLiteral.location, "conditional literals in aggregates currently unsupported", context);
conditionalLiteral.literal.data.accept(LiteralCollectFunctionTermsVisitor(), conditionalLiteral.literal, context);
}
}
void visit(const Clingo::AST::HeadAggregate &, const Clingo::AST::HeadLiteral &headLiteral, Context &context)
{
throwErrorAtLocation(headLiteral.location, "“head aggregate” head literals currently unsupported", context);
}
void visit(const Clingo::AST::TheoryAtom &, const Clingo::AST::HeadLiteral &headLiteral, Context &context)
{
throwErrorAtLocation(headLiteral.location, "“theory” head literals currently unsupported", context);
}
};
////////////////////////////////////////////////////////////////////////////////////////////////////
struct FunctionTermTranslateVisitor
{
std::experimental::optional<ast::Formula> visit(const Clingo::Symbol &, const Clingo::AST::Term &term, Context &context)
{
throwErrorAtLocation(term.location, "“symbol” terms not allowed, function expected", context);
return std::experimental::nullopt;
}
std::experimental::optional<ast::Formula> visit(const Clingo::AST::Variable &, const Clingo::AST::Term &term, Context &context)
{
throwErrorAtLocation(term.location, "“variable” terms currently unsupported, function expected", context);
return std::experimental::nullopt;
}
std::experimental::optional<ast::Formula> visit(const Clingo::AST::UnaryOperation &, const Clingo::AST::Term &term, Context &context)
{
throwErrorAtLocation(term.location, "“unary operation” terms currently unsupported, function expected", context);
return std::experimental::nullopt;
}
std::experimental::optional<ast::Formula> visit(const Clingo::AST::BinaryOperation &, const Clingo::AST::Term &term, Context &context)
{
throwErrorAtLocation(term.location, "“binary operation” terms currently unsupported, function expected", context);
return std::experimental::nullopt;
}
std::experimental::optional<ast::Formula> visit(const Clingo::AST::Interval &, const Clingo::AST::Term &term, Context &context)
{
throwErrorAtLocation(term.location, "“interval” terms currently unsupported, function expected", context);
return std::experimental::nullopt;
}
// TODO: check correctness
std::experimental::optional<ast::Formula> visit(const Clingo::AST::Function &function, const Clingo::AST::Term &term, Context &context)
{
if (function.external)
throwErrorAtLocation(term.location, "external functions currently unsupported", context);
std::vector<ast::Term> arguments;
arguments.reserve(function.arguments.size());
for (auto i = function.arguments.cbegin(); i != function.arguments.cend(); i++)
{
const auto &argument = *i;
const auto matchingTerm = std::find(context.headTerms.cbegin(), context.headTerms.cend(), &argument);
assert(matchingTerm != context.headTerms.cend());
auto variableName = std::string(AuxiliaryHeadVariablePrefix) + std::to_string(matchingTerm - context.headTerms.cbegin() + 1);
arguments.emplace_back(ast::Variable(std::move(variableName), ast::Variable::Type::Reserved));
}
return ast::Formula::make<ast::Predicate>(function.name, std::move(arguments));
}
std::experimental::optional<ast::Formula> visit(const Clingo::AST::Pool &, const Clingo::AST::Term &term, Context &context)
{
throwErrorAtLocation(term.location, "“pool” terms currently unsupported, function expected", context);
return std::experimental::nullopt;
}
};
////////////////////////////////////////////////////////////////////////////////////////////////////
struct LiteralTranslateVisitor
{
std::experimental::optional<ast::Formula> visit(const Clingo::AST::Boolean &boolean, const Clingo::AST::Literal &, Context &)
{
return ast::Formula::make<ast::Boolean>(boolean.value);
}
std::experimental::optional<ast::Formula> visit(const Clingo::AST::Term &term, const Clingo::AST::Literal &, Context &context)
{
return term.data.accept(FunctionTermTranslateVisitor(), term, context);
}
std::experimental::optional<ast::Formula> visit(const Clingo::AST::Comparison &, const Clingo::AST::Literal &literal, Context &context)
{
throwErrorAtLocation(literal.location, "only disjunctions of literals allowed as head literals", context);
return std::experimental::nullopt;
}
std::experimental::optional<ast::Formula> visit(const Clingo::AST::CSPLiteral &, const Clingo::AST::Literal &literal, Context &context)
{
throwErrorAtLocation(literal.location, "only disjunctions of literals allowed as head literals", context);
return std::experimental::nullopt;
}
};
////////////////////////////////////////////////////////////////////////////////////////////////////
struct HeadLiteralTranslateToConsequentVisitor
{
std::experimental::optional<ast::Formula> visit(const Clingo::AST::Literal &literal, const Clingo::AST::HeadLiteral &, Context &context)
{
if (literal.sign == Clingo::AST::Sign::DoubleNegation)
throwErrorAtLocation(literal.location, "double-negated head literals currently unsupported", context);
auto translatedLiteral = literal.data.accept(LiteralTranslateVisitor(), literal, context);
if (literal.sign == Clingo::AST::Sign::None)
return translatedLiteral;
if (!translatedLiteral)
return std::experimental::nullopt;
return ast::Formula::make<ast::Not>(std::move(translatedLiteral.value()));
}
std::experimental::optional<ast::Formula> visit(const Clingo::AST::Disjunction &disjunction, const Clingo::AST::HeadLiteral &headLiteral, Context &context)
{
std::vector<ast::Formula> arguments;
arguments.reserve(disjunction.elements.size());
for (const auto &conditionalLiteral : disjunction.elements)
{
if (!conditionalLiteral.condition.empty())
throwErrorAtLocation(headLiteral.location, "conditional head literals currently unsupported", context);
auto argument = visit(conditionalLiteral.literal, headLiteral, context);
if (!argument)
throwErrorAtLocation(headLiteral.location, "could not parse argument", context);
arguments.emplace_back(std::move(argument.value()));
}
return ast::Formula::make<ast::Or>(std::move(arguments));
}
std::experimental::optional<ast::Formula> visit(const Clingo::AST::Aggregate &aggregate, const Clingo::AST::HeadLiteral &headLiteral, Context &context)
{
if (aggregate.left_guard || aggregate.right_guard)
throwErrorAtLocation(headLiteral.location, "aggregates with left or right guards not allowed", context);
const auto translateConditionalLiteral =
[&](const auto &conditionalLiteral)
{
if (!conditionalLiteral.condition.empty())
throwErrorAtLocation(headLiteral.location, "conditional head literals currently unsupported", context);
return this->visit(conditionalLiteral.literal, headLiteral, context);
};
if (aggregate.elements.size() == 1)
return translateConditionalLiteral(aggregate.elements[0]);
std::vector<ast::Formula> arguments;
arguments.reserve(aggregate.elements.size());
for (const auto &conditionalLiteral : aggregate.elements)
{
auto argument = translateConditionalLiteral(conditionalLiteral);
if (!argument)
throwErrorAtLocation(headLiteral.location, "could not parse argument", context);
arguments.emplace_back(std::move(argument.value()));
}
return ast::Formula::make<ast::Or>(std::move(arguments));
}
std::experimental::optional<ast::Formula> visit(const Clingo::AST::HeadAggregate &, const Clingo::AST::HeadLiteral &headLiteral, Context &context)
{
throwErrorAtLocation(headLiteral.location, "“head aggregate” head literals currently unsupported", context);
return std::experimental::nullopt;
}
std::experimental::optional<ast::Formula> visit(const Clingo::AST::TheoryAtom &, const Clingo::AST::HeadLiteral &headLiteral, Context &context)
{
throwErrorAtLocation(headLiteral.location, "“theory” head literals currently unsupported", context);
return std::experimental::nullopt;
}
};
////////////////////////////////////////////////////////////////////////////////////////////////////
}
#endif