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process compound operators in the correct order

This commit is contained in:
Ari Lazier 2015-11-25 12:49:31 -08:00
parent 4b9af98a81
commit 295b378e7f
3 changed files with 91 additions and 89 deletions
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173
parser/parser.cpp
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@ -106,38 +106,91 @@ struct pred : seq< and_pred, star< or_ext > > {};
// state
struct ParserState
{
std::vector<Predicate *> predicate_stack;
Predicate &current()
std::vector<Predicate *> group_stack;
Predicate *current_group()
{
return *predicate_stack.back();
return group_stack.back();
}
bool current_is_compound()
Predicate *last_predicate()
{
return current().type == Predicate::Type::And || current().type == Predicate::Type::Or;
Predicate *pred = current_group();
while (pred->type != Predicate::Type::Comparison && pred->cpnd.sub_predicates.size()) {
pred = &pred->cpnd.sub_predicates.back();
}
return pred;
}
void add_predicate_to_current_group(Predicate::Type type)
{
current_group()->cpnd.sub_predicates.emplace_back(type, negate_next);
negate_next = false;
if (current_group()->cpnd.sub_predicates.size() > 1) {
if (next_type == Predicate::Type::Or) {
apply_or();
}
else {
apply_and();
}
}
}
bool negate_next = false;
Predicate::Type next_type = Predicate::Type::And;
void addExpression(Expression && exp)
void add_expression(Expression && exp)
{
Predicate &cur = current();
if (cur.type == Predicate::Type::Comparison) {
cur.cmpr.expr[1] = std::move(exp);
predicate_stack.pop_back();
Predicate *current = last_predicate();
if (current->type == Predicate::Type::Comparison && current->cmpr.expr[1].type == parser::Expression::Type::None) {
current->cmpr.expr[1] = std::move(exp);
}
else {
assert(current_is_compound());
Predicate p(Predicate::Type::Comparison);
p.cmpr.expr[0] = std::move(exp);
if (negate_next) {
p.negate = true;
negate_next = false;
}
add_predicate_to_current_group(Predicate::Type::Comparison);
last_predicate()->cmpr.expr[0] = std::move(exp);
}
}
void apply_or()
{
Predicate &group = *group_stack.back();
if (group.type == Predicate::Type::Or) {
return;
}
// convert to OR
group.type = Predicate::Type::Or;
if (group.cpnd.sub_predicates.size() > 2) {
// split the current group into an AND group ORed with the last subpredicate
Predicate new_sub(Predicate::Type::And);
new_sub.cpnd.sub_predicates = std::move(group.cpnd.sub_predicates);
cur.cpnd.sub_predicates.emplace_back(std::move(p));
predicate_stack.push_back(&cur.cpnd.sub_predicates.back());
group.cpnd.sub_predicates = { new_sub, std::move(new_sub.cpnd.sub_predicates.back()) };
group.cpnd.sub_predicates[0].cpnd.sub_predicates.pop_back();
}
}
void apply_and()
{
if (current_group()->type == Predicate::Type::And) {
return;
}
auto &sub_preds = current_group()->cpnd.sub_predicates;
auto second_last = sub_preds.end() - 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->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(Predicate::Type::And);
pred.cpnd.sub_predicates.insert(pred.cpnd.sub_predicates.begin(), second_last, sub_preds.end());
sub_preds.erase(second_last, sub_preds.end());
sub_preds.emplace_back(std::move(pred));
}
}
};
@ -152,68 +205,21 @@ struct action : nothing< Rule > {};
#define DEBUG_PRINT_TOKEN(string)
#endif
template<> struct action< and_ext >
template<> struct action< and_op >
{
static void apply( const input & in, ParserState & state )
{
DEBUG_PRINT_TOKEN("<and>");
assert(state.current_is_compound());
// 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 = 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.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(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(std::move(pred));
}
}
state.next_type = Predicate::Type::And;
}
};
template<> struct action< or_ext >
template<> struct action< or_op >
{
static void apply( const input & in, ParserState & state )
{
DEBUG_PRINT_TOKEN("<or>");
assert(state.current_is_compound());
// if already an OR group do nothing
auto &current = 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().cpnd.sub_predicates;
assert(sub_preds.size() > 1);
if (sub_preds.size() == 2) {
current.type = Predicate::Type::Or;
return;
}
// split the current group into to groups which are ORed together
Predicate pred1(Predicate::Type::And), pred2(Predicate::Type::And);
std::vector<Predicate>::iterator second_last = sub_preds.end() - 2;
pred1.cpnd.sub_predicates.insert(pred1.cpnd.sub_predicates.begin(), sub_preds.begin(), second_last);
pred2.cpnd.sub_predicates.insert(pred2.cpnd.sub_predicates.begin(), second_last, sub_preds.end());
current.type = Predicate::Type::Or;
sub_preds.clear();
sub_preds.emplace_back(std::move(pred1));
sub_preds.emplace_back(std::move(pred2));
state.next_type = Predicate::Type::Or;
}
};
@ -222,7 +228,7 @@ template<> struct action< or_ext >
template<> struct action< rule > { \
static void apply( const input & in, ParserState & state ) { \
DEBUG_PRINT_TOKEN(in.string()); \
state.addExpression(Expression(type, in.string())); }};
state.add_expression(Expression(type, in.string())); }};
EXPRESSION_ACTION(dq_string_content, Expression::Type::String)
EXPRESSION_ACTION(sq_string_content, Expression::Type::String)
@ -238,7 +244,7 @@ template<> struct action< true_pred >
static void apply( const input & in, ParserState & state )
{
DEBUG_PRINT_TOKEN(in.string());
state.current().cpnd.sub_predicates.emplace_back(Predicate::Type::True);
state.current_group()->cpnd.sub_predicates.emplace_back(Predicate::Type::True);
}
};
@ -247,7 +253,7 @@ template<> struct action< false_pred >
static void apply( const input & in, ParserState & state )
{
DEBUG_PRINT_TOKEN(in.string());
state.current().cpnd.sub_predicates.emplace_back(Predicate::Type::False);
state.current_group()->cpnd.sub_predicates.emplace_back(Predicate::Type::False);
}
};
@ -255,7 +261,7 @@ template<> struct action< false_pred >
template<> struct action< rule > { \
static void apply( const input & in, ParserState & state ) { \
DEBUG_PRINT_TOKEN(in.string()); \
state.current().cmpr.op = oper; }};
state.last_predicate()->cmpr.op = oper; }};
OPERATOR_ACTION(eq, Predicate::Operator::Equal)
OPERATOR_ACTION(noteq, Predicate::Operator::NotEqual)
@ -272,15 +278,8 @@ template<> struct action< one< '(' > >
static void apply( const input & in, ParserState & state )
{
DEBUG_PRINT_TOKEN("<begin_group>");
Predicate group(Predicate::Type::And);
if (state.negate_next) {
group.negate = true;
state.negate_next = false;
}
state.current().cpnd.sub_predicates.emplace_back(std::move(group));
state.predicate_stack.push_back(&state.current().cpnd.sub_predicates.back());
state.add_predicate_to_current_group(Predicate::Type::And);
state.group_stack.push_back(state.last_predicate());
}
};
@ -289,7 +288,7 @@ template<> struct action< group_pred >
static void apply( const input & in, ParserState & state )
{
DEBUG_PRINT_TOKEN("<end_group>");
state.predicate_stack.pop_back();
state.group_stack.pop_back();
}
};
@ -322,10 +321,12 @@ const std::string error_message_control< Rule >::error_message = "Invalid predic
Predicate parse(const std::string &query)
{
DEBUG_PRINT_TOKEN(query);
Predicate out_predicate(Predicate::Type::And);
ParserState state;
state.predicate_stack.push_back(&out_predicate);
state.group_stack.push_back(&out_predicate);
pegtl::parse< must< pred, eof >, action, error_message_control >(query, query, state);
if (out_predicate.type == Predicate::Type::And && out_predicate.cpnd.sub_predicates.size() == 1) {

4
parser/parser.hpp
View File

@ -28,7 +28,7 @@ namespace realm {
namespace parser {
struct Expression
{
enum class Type { Number, String, KeyPath, Argument, True, False } type;
enum class Type { Number, String, KeyPath, Argument, True, False, None } type = Type::None;
std::string s;
Expression() {}
Expression(Type t, std::string s) : type(t), s(s) {}
@ -76,7 +76,7 @@ namespace realm {
bool negate = false;
Predicate(Type t) : type(t) {}
Predicate(Type t, bool n = false) : type(t), negate(n) {}
};
Predicate parse(const std::string &query);

3
parser/queryTests.json
View File

@ -267,7 +267,8 @@
["ObjectSet", [0], "IntObject", "intCol == 0 && NOT intCol != 0"],
["ObjectSet", [1], "IntObject", "(intCol == 0 || intCol == 1) && intCol >= 1"],
["ObjectSet", [0, 1], "IntObject", "intCol == 0 || (intCol == 1 && intCol >= 1)"],
["ObjectSet", [0, 1], "IntObject", "intCol == 0 || intCol == 1 && intCol >= 1"]
["ObjectSet", [0, 1], "IntObject", "intCol == 0 || intCol == 1 && intCol >= 1"],
["ObjectSet", [0, 1], "IntObject", "intCol == 1 && intCol >= 1 || intCol == 0"]
]
}