37 lines
No EOL
1.3 KiB
C++
37 lines
No EOL
1.3 KiB
C++
#include "item_set_closure.h"
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#include "tree_sitter/compiler.h"
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#include "./follow_sets.h"
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#include "item.h"
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#include <algorithm>
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namespace tree_sitter {
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using std::set;
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using rules::Symbol;
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namespace build_tables {
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static bool contains(const ParseItemSet &items, const ParseItem &item) {
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return items.size() > 0 && (std::find(items.begin(), items.end(), item) != items.end());
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}
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static void add_item(ParseItemSet &item_set, const ParseItem &item, const Grammar &grammar) {
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if (!contains(item_set, item)) {
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item_set.insert(item);
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for (auto pair : follow_sets(item, grammar)) {
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Symbol non_terminal = pair.first;
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set<Symbol> terminals = pair.second;
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for (auto &terminal : terminals) {
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ParseItem next_item(non_terminal, grammar.rule(non_terminal), {}, terminal);
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add_item(item_set, next_item, grammar);
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}
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}
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}
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}
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const ParseItemSet item_set_closure(const ParseItemSet &item_set, const Grammar &grammar) {
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ParseItemSet result;
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for (ParseItem item : item_set)
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add_item(result, item, grammar);
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return result;
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}
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}
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} |