diff --git a/parser/parser.cpp b/parser/parser.cpp index 770cab77..ba4fd68f 100644 --- a/parser/parser.cpp +++ b/parser/parser.cpp @@ -100,25 +100,26 @@ struct pred : seq< and_pred, star< or_ext > > {}; struct ParserState { std::vector predicate_stack; - Predicate *current() { return predicate_stack.back(); } + Predicate ¤t() { + return *predicate_stack.back(); + } bool negate_next; void addExpression(Expression exp) { - if (current()->type == Predicate::Type::Comparison) { - current()->sub_expressions.emplace_back(std::move(exp)); + if (current().type == Predicate::Type::Comparison) { + current().cmpr.expr[1] = std::move(exp); predicate_stack.pop_back(); } else { - Predicate p; - p.type = Predicate::Type::Comparison; - p.sub_expressions.emplace_back(std::move(exp)); + Predicate p(Predicate::Type::Comparison); + p.cmpr.expr[0] = std::move(exp); if (negate_next) { p.negate = true; negate_next = false; } - current()->sub_predicates.emplace_back(std::move(p)); - predicate_stack.push_back(¤t()->sub_predicates.back()); + current().cpnd.sub_predicates.emplace_back(std::move(p)); + predicate_stack.push_back(¤t().cpnd.sub_predicates.back()); } } }; @@ -134,24 +135,24 @@ template<> struct action< and_ext > std::cout << "" << in.string() << std::endl; // if we were put into an OR group we need to rearrange - auto current = state.current(); - if (current->type == Predicate::Type::Or) { - auto &sub_preds = state.current()->sub_predicates; - auto second_last = sub_preds[sub_preds.size()-2]; + auto ¤t = state.current(); + if (current.type == Predicate::Type::Or) { + auto &sub_preds = state.current().cpnd.sub_predicates; + auto &second_last = sub_preds[sub_preds.size()-2]; if (second_last.type == Predicate::Type::And) { // if we are in an OR group and second to last predicate group is // an AND group then move the last predicate inside - second_last.sub_predicates.push_back(sub_preds.back()); + second_last.cpnd.sub_predicates.push_back(std::move(sub_preds.back())); sub_preds.pop_back(); } else { // otherwise combine last two into a new AND group - Predicate pred; - pred.type = Predicate::Type::And; - pred.sub_predicates = { second_last, sub_preds.back() }; + Predicate pred(Predicate::Type::And); + pred.cpnd.sub_predicates.emplace_back(std::move(second_last)); + pred.cpnd.sub_predicates.emplace_back(std::move(sub_preds.back())); sub_preds.pop_back(); sub_preds.pop_back(); - sub_preds.push_back(pred); + sub_preds.push_back(std::move(pred)); } } } @@ -164,27 +165,27 @@ template<> struct action< or_ext > std::cout << "" << in.string() << std::endl; // if already an OR group do nothing - auto current = state.current(); - if (current->type == Predicate::Type::Or) { + auto ¤t = state.current(); + if (current.type == Predicate::Type::Or) { return; } // if only two predicates in the group, then convert to OR - auto &sub_preds = state.current()->sub_predicates; + auto &sub_preds = state.current().cpnd.sub_predicates; if (sub_preds.size()) { - current->type = Predicate::Type::Or; + current.type = Predicate::Type::Or; return; } // split the current group into to groups which are ORed together - Predicate pred1, pred2; - pred1.type = Predicate::Type::And; - pred2.type = Predicate::Type::And; - pred1.sub_predicates.insert(sub_preds.begin(), sub_preds.back()); - pred2.sub_predicates.push_back(sub_preds.back()); + Predicate pred1(Predicate::Type::And), pred2(Predicate::Type::And); + pred1.cpnd.sub_predicates.insert(sub_preds.begin(), sub_preds.back()); + pred2.cpnd.sub_predicates.push_back(std::move(sub_preds.back())); - current->type = Predicate::Type::Or; - sub_preds = { pred1, pred2 }; + current.type = Predicate::Type::Or; + sub_preds.clear(); + sub_preds.emplace_back(std::move(pred1)); + sub_preds.emplace_back(std::move(pred2)); } }; @@ -249,9 +250,8 @@ template<> struct action< true_pred > static void apply( const input & in, ParserState & state ) { std::cout << in.string() << std::endl; - Predicate pred; - pred.type = Predicate::Type::True; - state.current()->sub_predicates.push_back(std::move(pred)); + Predicate pred(Predicate::Type::True); + state.current().cpnd.sub_predicates.push_back(std::move(pred)); } }; @@ -260,9 +260,8 @@ template<> struct action< false_pred > static void apply( const input & in, ParserState & state ) { std::cout << in.string() << std::endl; - Predicate pred; - pred.type = Predicate::Type::False; - state.current()->sub_predicates.push_back(std::move(pred)); + Predicate pred(Predicate::Type::False); + state.current().cpnd.sub_predicates.push_back(std::move(pred)); } }; @@ -270,7 +269,7 @@ template<> struct action< false_pred > template<> struct action< rule > { \ static void apply( const input & in, ParserState & state ) { \ std::cout << in.string() << std::endl; \ - state.current()->op = oper; }}; + state.current().cmpr.op = oper; }}; OPERATOR_ACTION(eq, Predicate::Operator::Equal) OPERATOR_ACTION(noteq, Predicate::Operator::NotEqual) @@ -289,15 +288,14 @@ template<> struct action< one< '(' > > { std::cout << "" << std::endl; - Predicate group; - group.type = Predicate::Type::And; + Predicate group(Predicate::Type::And); if (state.negate_next) { group.negate = true; state.negate_next = false; } - state.current()->sub_predicates.emplace_back(std::move(group)); - state.predicate_stack.push_back(&state.current()->sub_predicates.back()); + state.current().cpnd.sub_predicates.emplace_back(std::move(group)); + state.predicate_stack.push_back(&state.current().cpnd.sub_predicates.back()); } }; @@ -326,21 +324,19 @@ Predicate parse(const std::string &query) analyze< pred >(); const std::string source = "user query"; - Predicate out_predicate; - out_predicate.type = Predicate::Type::And; + Predicate out_predicate(Predicate::Type::And); ParserState state; state.predicate_stack.push_back(&out_predicate); pegtl::parse< must< pred, eof >, action >(query, source, state); - if (out_predicate.type == Predicate::Type::And && out_predicate.sub_predicates.size() == 1) { - return out_predicate.sub_predicates.back(); + if (out_predicate.type == Predicate::Type::And && out_predicate.cpnd.sub_predicates.size() == 1) { + return std::move(out_predicate.cpnd.sub_predicates.back()); } - return out_predicate; + return std::move(out_predicate); } - // check a precondition and throw an exception if it is not met // this should be used iff the condition being false indicates a bug in the caller // of the function checking its preconditions @@ -618,14 +614,15 @@ template void add_comparison_to_query(Query &query, Predicate &pred, Schema &schema, ObjectSchema &object_schema) { std::vector indexes; - auto t0 = pred.sub_expressions[0].type, t1 = pred.sub_expressions[1].type; + Predicate::Comparison &cmpr = pred.cmpr; + auto t0 = cmpr.expr[0].type, t1 = cmpr.expr[1].type; if (t0 == Expression::Type::KeyPath && t1 != Expression::Type::KeyPath) { - Property *prop = get_property_from_key_path(schema, object_schema, pred.sub_expressions[0].s, indexes); - do_add_comparison_to_query(query, schema, object_schema, prop, pred.op, indexes, prop->table_column, pred.sub_expressions[1].s); + Property *prop = get_property_from_key_path(schema, object_schema, cmpr.expr[0].s, indexes); + do_add_comparison_to_query(query, schema, object_schema, prop, cmpr.op, indexes, prop->table_column, cmpr.expr[1].s); } else if (t0 != Expression::Type::KeyPath && t1 == Expression::Type::KeyPath) { - Property *prop = get_property_from_key_path(schema, object_schema, pred.sub_expressions[1].s, indexes); - do_add_comparison_to_query(query, schema, object_schema, prop, pred.op, indexes, pred.sub_expressions[0].s, prop->table_column); + Property *prop = get_property_from_key_path(schema, object_schema, cmpr.expr[1].s, indexes); + do_add_comparison_to_query(query, schema, object_schema, prop, cmpr.op, indexes, cmpr.expr[0].s, prop->table_column); } else { throw std::runtime_error("Predicate expressions must compare a keypath and another keypath or a constant value"); @@ -641,10 +638,10 @@ void update_query_with_predicate(Query &query, Predicate &pred, Schema &schema, switch (pred.type) { case Predicate::Type::And: query.group(); - for (auto &sub : pred.sub_predicates) { + for (auto &sub : pred.cpnd.sub_predicates) { update_query_with_predicate(query, sub, schema, object_schema); } - if (!pred.sub_predicates.size()) { + if (!pred.cpnd.sub_predicates.size()) { query.and_query(new TrueExpression); } query.end_group(); @@ -652,11 +649,11 @@ void update_query_with_predicate(Query &query, Predicate &pred, Schema &schema, case Predicate::Type::Or: query.group(); - for (auto &sub : pred.sub_predicates) { + for (auto &sub : pred.cpnd.sub_predicates) { query.Or(); update_query_with_predicate(query, sub, schema, object_schema); } - if (!pred.sub_predicates.size()) { + if (!pred.cpnd.sub_predicates.size()) { query.and_query(new FalseExpression); } query.end_group(); diff --git a/parser/parser.hpp b/parser/parser.hpp index 99dda99d..c53887f5 100644 --- a/parser/parser.hpp +++ b/parser/parser.hpp @@ -29,33 +29,21 @@ namespace realm { namespace parser { struct Expression { - enum class Type - { - Number, - String, - KeyPath, - }; - Type type; - + enum class Type { Number, String, KeyPath } type; std::string s; }; struct Predicate { - enum class Type - { - None, + enum class Type { Comparison, Or, And, True, - False, - }; - Type type = Type::None; + False + } type = Type::And; - // for comparison - enum class Operator - { + enum class Operator { None, Equal, NotEqual, @@ -65,15 +53,25 @@ namespace realm { GreaterThanOrEqual, BeginsWith, EndsWith, - Contains, + Contains }; - Operator op = Operator::None; - std::vector sub_expressions; - // for compounds - std::vector sub_predicates; + struct Comparison { + Operator op = Operator::None; + Expression expr[2]; + ~Comparison() {} + }; - bool negate; + struct Compound { + std::vector sub_predicates; + }; + + Comparison cmpr; + Compound cpnd; + + bool negate = false; + + Predicate(Type t) : type(t) {} }; Predicate parse(const std::string &query);