56 lines
1.8 KiB
C++
56 lines
1.8 KiB
C++
#include "item.h"
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#include "grammar.h"
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#include "transitions.h"
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#include <iostream>
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using namespace std;
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namespace tree_sitter {
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namespace lr {
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Item::Item(const std::string &rule_name, const rules::rule_ptr rule, int consumed_sym_count) :
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rule_name(rule_name),
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rule(rule),
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consumed_sym_count(consumed_sym_count) {};
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Item Item::at_beginning_of_rule(const std::string &rule_name, const Grammar &grammar) {
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return Item(rule_name, grammar.rule(rule_name), 0);
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}
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transition_map<rules::Rule, Item> Item::transitions() const {
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return rules::transitions(rule).map<Item>([&](rules::rule_ptr to_rule) -> item_ptr {
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return std::make_shared<Item>(rule_name, to_rule, consumed_sym_count + 1);
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});
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};
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vector<rules::Symbol> Item::next_symbols() const {
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vector<rules::Symbol> result;
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for (auto pair : rules::transitions(rule)) {
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shared_ptr<const rules::Symbol> sym = dynamic_pointer_cast<const rules::Symbol>(pair.first);
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if (sym) result.push_back(*sym);
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}
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return result;
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}
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bool Item::operator==(const Item &other) const {
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bool rule_names_eq = other.rule_name == rule_name;
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bool rules_eq = (*other.rule == *rule);
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return rule_names_eq && rules_eq;
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}
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bool Item::is_done() const {
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return *rule == rules::Blank();
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}
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std::ostream& operator<<(ostream &stream, const Item &item) {
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stream <<
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string("(item '") <<
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item.rule_name <<
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string("' ") <<
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*item.rule <<
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string(")");
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return stream;
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}
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}
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}
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