ChaiScript/langkit/langkit_parser.cpp

88 lines
2.9 KiB
C++

// This file is distributed under the BSD License.
// See LICENSE.TXT for details.
#include <iostream>
#include <utility>
#include "langkit_lexer.hpp"
#include "langkit_parser.hpp"
std::pair<Token_Iterator, bool> String_Rule(Token_Iterator iter, Token_Iterator end, TokenPtr parent, const std::string &val, bool keep) {
if (*iter != *end) {
if ((*iter)->text == val) {
if (keep) {
parent->children.push_back(*iter);
}
return std::pair<Token_Iterator, bool>(++iter, true);
}
}
return std::pair<Token_Iterator, bool>(iter, false);
}
std::pair<Token_Iterator, bool> Type_Rule(Token_Iterator iter, Token_Iterator end, TokenPtr parent, const int val, bool keep) {
if (*iter != *end) {
if ((*iter)->identifier == val) {
if (keep) {
parent->children.push_back(*iter);
}
return std::pair<Token_Iterator, bool>(++iter, true);
}
}
return std::pair<Token_Iterator, bool>(iter, false);
}
std::pair<Token_Iterator, bool> Or_Rule(Token_Iterator iter, Token_Iterator end, TokenPtr parent, const RulePtr lhs, const RulePtr rhs, bool keep) {
Token_Iterator new_iter;
unsigned int prev_size = parent->children.size();
if (*iter != *end) {
std::pair<Token_Iterator, bool> result = lhs->rule(iter, end, parent);
if (result.second) {
return std::pair<Token_Iterator, bool>(result.first, true);
}
else {
result = rhs->rule(iter, end, parent);
if (result.second) {
return std::pair<Token_Iterator, bool>(result.first, true);
}
}
}
if (parent->children.size() != prev_size) {
//Clear out the partial matches
parent->children.erase(parent->children.begin() + prev_size, parent->children.end());
}
return std::pair<Token_Iterator, bool>(iter, false);
}
std::pair<Token_Iterator, bool> And_Rule(Token_Iterator iter, Token_Iterator end, TokenPtr parent, const RulePtr lhs, const RulePtr rhs, bool keep) {
Token_Iterator lhs_iter, rhs_iter;
unsigned int prev_size = parent->children.size();
if (*iter != *end) {
std::pair<Token_Iterator, bool> result = lhs->rule(iter, end, parent);
if (result.second) {
result = rhs->rule(result.first, end, parent);
if (result.second) {
return std::pair<Token_Iterator, bool>(result.first, true);
}
}
}
if (parent->children.size() != prev_size) {
//Clear out the partial matches
parent->children.erase(parent->children.begin() + prev_size, parent->children.end());
}
return std::pair<Token_Iterator, bool>(iter, false);
}
std::pair<Token_Iterator, bool> Rule::operator()(Token_Iterator iter, Token_Iterator end, TokenPtr parent) {
return this->rule(iter, end, parent);
}