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/*
Ousía
Copyright (C) 2014, 2015 Benjamin Paaßen, Andreas Stöckel
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <sstream>
#include <core/common/Utils.hpp>
#include <core/common/Exceptions.hpp>
#include <core/model/Project.hpp>
#include "ParserScope.hpp"
#include "ParserStack.hpp"
namespace ousia {
/* A default handler */
/**
* The DefaultHandler class is used in case no element handler is specified in
* the ParserState descriptor.
*/
class DefaultHandler : public Handler {
public:
using Handler::Handler;
void start(Variant::mapType &args) override {}
void end() override {}
static Handler *create(const HandlerData &handlerData)
{
return new DefaultHandler{handlerData};
}
};
/* Class Handler */
void Handler::data(const std::string &data, int field)
{
for (auto &c : data) {
if (!Utils::isWhitespace(c)) {
logger().error("Expected command but found character data.");
return;
}
}
}
/* Class ParserStack */
/**
* Returns an Exception that should be thrown when a currently invalid command
* is thrown.
*/
static LoggableException InvalidCommand(const std::string &name,
const std::set<std::string> &expected)
{
if (expected.empty()) {
return LoggableException{
std::string{"No nested elements allowed, but got \""} + name +
std::string{"\""}};
} else {
return LoggableException{
std::string{"Expected "} +
(expected.size() == 1 ? std::string{"\""}
: std::string{"one of \""}) +
Utils::join(expected, "\", \"") + std::string{"\", but got \""} +
name + std::string{"\""}};
}
}
ParserStack::ParserStack(
ParserContext &ctx,
const std::multimap<std::string, const ParserState *> &states)
: ctx(ctx), states(states)
{
}
bool ParserStack::deduceState()
{
// Assemble all states
std::vector<const ParserState *> states;
for (const auto &e : this->states) {
states.push_back(e.second);
}
// Fetch the type signature of the scope and derive all possible states,
// abort if no unique parser state was found
std::vector<const ParserState *> possibleStates =
ParserStateDeductor(ctx.getScope().getStackTypeSignature(), states)
.deduce();
if (possibleStates.size() != 1) {
ctx.getLogger().error(
"Error while including file: Cannot deduce parser state.");
return false;
}
// Switch to this state by creating a dummy handler
const ParserState *state = possibleStates[0];
Handler *handler =
DefaultHandler::create({ctx, "", *state, *state, SourceLocation{}});
stack.emplace(handler);
return true;
}
std::set<std::string> ParserStack::expectedCommands(const ParserState &state)
{
std::set<std::string> res;
for (const auto &v : states) {
if (v.second->parents.count(&state)) {
res.insert(v.first);
}
}
return res;
}
const ParserState &ParserStack::currentState()
{
return stack.empty() ? ParserStates::None : stack.top()->state();
}
std::string ParserStack::currentCommandName()
{
return stack.empty() ? std::string{} : stack.top()->name();
}
void ParserStack::start(std::string name, Variant::mapType &args,
const SourceLocation &location)
{
// Fetch the current handler and the current state
ParserState const *currentState = &(this->currentState());
// Fetch the correct Handler descriptor for this
ParserState const *targetState = nullptr;
HandlerConstructor ctor = nullptr;
auto range = states.equal_range(name);
for (auto it = range.first; it != range.second; it++) {
const ParserStateSet &parents = it->second->parents;
if (parents.count(currentState) || parents.count(&ParserStates::All)) {
targetState = it->second;
ctor = targetState->elementHandler ? targetState->elementHandler
: DefaultHandler::create;
break;
}
}
// Try to use the child handler if one was given
if (!targetState && currentState->childHandler) {
targetState = currentState;
ctor = targetState->childHandler;
}
// No descriptor found, throw an exception.
if (!targetState || !ctor) {
throw InvalidCommand(name, expectedCommands(*currentState));
}
// Canonicalize the arguments, allow additional arguments
targetState->arguments.validateMap(args, ctx.getLogger(), true);
// Instantiate the handler and call its start function
Handler *handler = ctor({ctx, name, *targetState, *currentState, location});
handler->start(args);
stack.emplace(handler);
}
void ParserStack::start(std::string name, const Variant::mapType &args,
const SourceLocation &location)
{
Variant::mapType argsCopy(args);
start(name, argsCopy);
}
void ParserStack::end()
{
// Check whether the current command could be ended
if (stack.empty()) {
throw LoggableException{"No command to end."};
}
// Remove the current HandlerInstance from the stack
std::shared_ptr<Handler> inst{stack.top()};
stack.pop();
// Call the end function of the last Handler
inst->end();
}
void ParserStack::data(const std::string &data, int field)
{
// Check whether there is any command the data can be sent to
if (stack.empty()) {
throw LoggableException{"No command to receive data."};
}
// Pass the data to the current Handler instance
stack.top()->data(data, field);
}
}
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