tree-sitter/src/compiler/rules/choice.cc
2015-07-31 16:32:24 -07:00

76 lines
1.8 KiB
C++

#include "compiler/rules/choice.h"
#include <string>
#include <set>
#include "compiler/rules/visitor.h"
namespace tree_sitter {
namespace rules {
using std::string;
using std::make_shared;
using std::vector;
using std::set;
using std::dynamic_pointer_cast;
Choice::Choice(const vector<rule_ptr> &elements) : elements(elements) {}
void add_choice_element(vector<rule_ptr> *vec, const rule_ptr new_rule) {
auto choice = dynamic_pointer_cast<const Choice>(new_rule);
if (choice.get()) {
for (auto &child : choice->elements)
add_choice_element(vec, child);
} else {
for (auto &el : *vec)
if (el->operator==(*new_rule))
return;
vec->push_back(new_rule);
}
}
rule_ptr Choice::build(const vector<rule_ptr> &inputs) {
vector<rule_ptr> elements;
for (auto &el : inputs)
add_choice_element(&elements, el);
if (elements.size() == 1)
return elements.front();
else
return make_shared<Choice>(elements);
}
bool Choice::operator==(const Rule &rule) const {
const Choice *other = dynamic_cast<const Choice *>(&rule);
if (!other)
return false;
size_t size = elements.size();
if (size != other->elements.size())
return false;
for (size_t i = 0; i < size; i++)
if (!elements[i]->operator==(*other->elements[i]))
return false;
return true;
}
size_t Choice::hash_code() const {
size_t result = std::hash<size_t>()(elements.size());
for (const auto &element : elements)
result ^= element->hash_code();
return result;
}
rule_ptr Choice::copy() const {
return std::make_shared<Choice>(*this);
}
string Choice::to_string() const {
string result = "(choice";
for (const auto &element : elements)
result += " " + element->to_string();
return result + ")";
}
void Choice::accept(Visitor *visitor) const {
visitor->visit(this);
}
} // namespace rules
} // namespace tree_sitter