Parsodus/src/inputparser.cpp

78 lines
2.6 KiB
C++

#include "ParsodusLexer.h"
#include "Parsodus/inputparser.h"
#include "Parsodus/parser.h"
#include "Parsodus/util/parserType.h"
#include "Lexesis/inputparser.h"
#include "g3log/g3log.hpp"
#include <set>
#include <fstream>
namespace pds {
InputParserException::InputParserException(std::string what): m_what(what) {}
const char* InputParserException::what() const throw() {
return m_what.c_str();
}
Config InputParser::parseInput(std::istream& is, std::string current_dir) {
ParsodusLexer lex(is);
Parser parser(lex);
Config cnf = *parser.parse();
if (!cnf.lexesisFile.empty()) {
std::fstream file(current_dir + cnf.lexesisFile);
auto terminals = lxs::input::InputParser::getTokens(file);
for(auto& terminal : terminals)
cnf.grammar.terminals.insert(terminal);
}
for(auto& rule : cnf.grammar.rules) {
for(auto& tail_piece : rule->tail) {
if (cnf.grammar.terminals.find(tail_piece) == cnf.grammar.terminals.end() &&
cnf.grammar.variables.find(tail_piece) == cnf.grammar.variables.end() && tail_piece != "error")
throw InputParserException("Found '" + tail_piece + "' in rule body, which is neither a variable nor a terminal.");
}
}
for(auto& rule : cnf.grammar.rules)
if (rule->head == "error")
throw InputParserException("Found <error> terminal in a head of a rule.");
bool found_token;
for(auto& term : cnf.grammar.terminals) {
found_token = false;
for(auto& rule : cnf.grammar.rules) {
for(auto& tail_value : rule->tail) {
if (tail_value == term) {
found_token = true;
break;
}
}
if (found_token) break;
}
if (!found_token)
LOG(WARNING) << "Terminal '" << term << "' is specified, but never used." << std::endl;
}
// Set precedence of each rule
for(std::shared_ptr<Rule>& rule : cnf.grammar.rules) {
if (rule->precedence.first) continue;
if (rule->tail.size() == 0)
rule->precedence = {false,{0,PrecedenceType::RIGHT}};
std::string rightmostTerm;
for (const std::string& term : rule->tail) {
if (cnf.grammar.terminals.count(term)) {
rightmostTerm = term;
}
}
auto prec = cnf.grammar.precedence.find(rightmostTerm);
if (prec != cnf.grammar.precedence.end())
rule->precedence = {true,prec->second};
else rule->precedence = {false,{0, PrecedenceType::RIGHT}};
}
return cnf;
}
}