tree-sitter/src/compiler/build_tables/rule_transitions.cpp

120 lines
4.4 KiB
C++

#include "rule_transitions.h"
#include "rule_can_be_blank.h"
#include "merge_transitions.h"
#include "rules/blank.h"
#include "rules/choice.h"
#include "rules/seq.h"
#include "rules/string.h"
#include "rules/repeat.h"
#include "rules/pattern.h"
#include "rules/visitor.h"
#include "rules/character_set.h"
namespace tree_sitter {
using std::map;
using std::set;
using std::make_shared;
using namespace rules;
namespace build_tables {
bool is_blank(const rule_ptr &rule) {
return typeid(*rule) == typeid(Blank);
}
template<typename T>
map<T, rule_ptr> merge_transitions(const map<T, rule_ptr> &left, const map<T, rule_ptr> &right);
template<>
map<CharacterSet, rule_ptr> merge_transitions(const map<CharacterSet, rule_ptr> &left, const map<CharacterSet, rule_ptr> &right) {
auto transitions = merge_char_transitions<rule_ptr>(left, right, [](rule_ptr left, rule_ptr right) -> rule_ptr {
return make_shared<Choice>(left, right);
});
return *static_cast<map<CharacterSet, rule_ptr> *>(&transitions);
}
template<>
map<Symbol, rule_ptr> merge_transitions(const map<Symbol, rule_ptr> &left, const map<Symbol, rule_ptr> &right) {
auto transitions = merge_sym_transitions<rule_ptr>(left, right, [](rule_ptr left, rule_ptr right) -> rule_ptr {
return make_shared<Choice>(left, right);
});
return *static_cast<map<Symbol, rule_ptr> *>(&transitions);
}
template<typename T>
map<T, rule_ptr> map_transitions(const map<T, rule_ptr> &initial, std::function<const rule_ptr(rule_ptr)> map_fn) {
map<T, rule_ptr> result;
for (auto &pair : initial)
result.insert({ pair.first, map_fn(pair.second) });
return result;
}
template<typename T>
class TransitionsVisitor : public rules::Visitor {
public:
map<T, rule_ptr> value;
static map<T, rule_ptr> transitions(const rule_ptr rule) {
TransitionsVisitor<T> visitor;
rule->accept(visitor);
return visitor.value;
}
void visit_atom(const Rule *rule) {
auto atom = dynamic_cast<const T *>(rule);
if (atom) {
value = map<T, rule_ptr>();
value.insert({ *atom, make_shared<Blank>() });
}
}
void visit(const CharacterSet *rule) {
visit_atom(rule);
}
void visit(const Symbol *rule) {
visit_atom(rule);
}
void visit(const Choice *rule) {
value = transitions(rule->left);
value = merge_transitions<T>(transitions(rule->left), transitions(rule->right));
}
void visit(const Seq *rule) {
value = map_transitions(transitions(rule->left), [&](const rule_ptr left_rule) {
return Seq::Build({ left_rule, rule->right });
});
if (rule_can_be_blank(rule->left)) {
value = merge_transitions<T>(value, transitions(rule->right));
}
}
void visit(const Repeat *rule) {
value = map_transitions(transitions(rule->content), [&](const rule_ptr &value) {
return Seq::Build({
value,
make_shared<Choice>(rule->copy(), make_shared<Blank>()) });
});
}
void visit(const String *rule) {
rule_ptr result = make_shared<Blank>();
for (char val : rule->value)
result = Seq::Build({ result, make_shared<CharacterSet>(set<CharacterRange>({ val })) });
value = transitions(result);
}
void visit(const Pattern *rule) {
value = transitions(rule->to_rule_tree());
}
};
map<CharacterSet, rule_ptr> char_transitions(const rule_ptr &rule) {
return TransitionsVisitor<CharacterSet>::transitions(rule);
}
map<Symbol, rule_ptr> sym_transitions(const rule_ptr &rule) {
return TransitionsVisitor<Symbol>::transitions(rule);
}
}
}