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Eliminate duplicates when constructing choice rules

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This commit is contained in:
Max Brunsfeld 2014-08-20 22:53:52 -07:00
parent fcdcdca303
commit 2963b08f79
2 changed files with 72 additions and 2 deletions
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23
src/compiler/rules/choice.cc
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@ -14,8 +14,27 @@ using std::dynamic_pointer_cast;
Choice::Choice(const vector<rule_ptr> &elements) : elements(elements) {}
rule_ptr Choice::Build(const vector<rule_ptr> &elements) {
return make_shared<Choice>(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 {