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cpp-peglib
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Simplefied code.

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pull/3/head
yhirose 9 years ago
parent 30971d28de
commit 2aa60699be
3 changed files with 73 additions and 95 deletions
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  1. 19
      README.md
  2. 127
      peglib.h
  3. 22
      test/test.cc

19
README.md
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@ -41,19 +41,20 @@ int main(void) {
peg parser(syntax);
// (3) Setup an action
parser["Additive"] = {
nullptr, // Default action
[](const SemanticValues& sv) {
return sv[0].get<int>() + sv[1].get<int>(); // "Multitive '+' Additive"
},
[](const SemanticValues& sv) { return sv[0]; } // "Multitive"
parser["Additive"] = [](const SemanticValues& sv) {
switch (sv.choice) {
case 0: // "Multitive '+' Additive"
return sv[0].get<int>() + sv[1].get<int>();
default: // "Multitive"
return sv[0].get<int>();
}
};
parser["Multitive"] = [](const SemanticValues& sv) {
switch (sv.choice) {
case 0: // "Multitive '+' Additive"
case 0: // "Primary '*' Multitive"
return sv[0].get<int>() * sv[1].get<int>();
default: // "Multitive"
default: // "Primary"
return sv[0].get<int>();
}
};
@ -63,7 +64,7 @@ int main(void) {
};
// (4) Parse
parser.packrat_parsing(true); // Enable packrat parsing.
parser.packrat_parsing(); // Enable packrat parsing.
int val;
parser.parse("(1+2)*3", val);

127
peglib.h
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@ -946,7 +946,7 @@ public:
void accept(Visitor& v) override;
any reduce(const SemanticValues& sv, any& dt, const Action& action) const;
any reduce(const SemanticValues& sv, any& dt) const;
std::shared_ptr<Ope> ope_;
Definition* outer_;
@ -1076,15 +1076,13 @@ public:
};
Definition()
: actions(1)
, ignoreSemanticValue(false)
: ignoreSemanticValue(false)
, enablePackratParsing(false)
, is_token(false)
, holder_(std::make_shared<Holder>(this)) {}
Definition(const Definition& rhs)
: name(rhs.name)
, actions(1)
, ignoreSemanticValue(false)
, enablePackratParsing(false)
, is_token(false)
@ -1095,7 +1093,6 @@ public:
Definition(Definition&& rhs)
: name(std::move(rhs.name))
, actions(1)
, ignoreSemanticValue(rhs.ignoreSemanticValue)
, enablePackratParsing(rhs.enablePackratParsing)
, is_token(rhs.is_token)
@ -1105,8 +1102,7 @@ public:
}
Definition(const std::shared_ptr<Ope>& ope)
: actions(1)
, ignoreSemanticValue(false)
: ignoreSemanticValue(false)
, enablePackratParsing(false)
, is_token(false)
, holder_(std::make_shared<Holder>(this))
@ -1182,14 +1178,8 @@ public:
return parse_and_get_value(s, n, dt, val);
}
Definition& operator=(Action action) {
assert(!actions.empty());
actions[0] = action;
return *this;
}
Definition& operator=(std::initializer_list<Action> ini) {
actions = ini;
Definition& operator=(Action a) {
action = a;
return *this;
}
@ -1210,7 +1200,7 @@ public:
std::string name;
size_t id;
std::vector<Action> actions;
Action action;
std::function<std::string ()> error_message;
bool ignoreSemanticValue;
bool enablePackratParsing;
@ -1258,13 +1248,6 @@ inline size_t Holder::parse(const char* s, size_t n, SemanticValues& sv, Context
// Invoke action
if (success(len)) {
assert(!outer_->actions.empty());
auto i = chldsv.choice + 1; // Index 0 is for the default action
const auto& action = (i < outer_->actions.size() && outer_->actions[i])
? outer_->actions[i]
: outer_->actions[0];
if (chldsv.s) {
anchors = chldsv.s;
anchorn = chldsv.n;
@ -1274,7 +1257,7 @@ inline size_t Holder::parse(const char* s, size_t n, SemanticValues& sv, Context
}
try {
val = reduce(chldsv, dt, action);
val = reduce(chldsv, dt);
} catch (const parse_error& e) {
if (e.what()) {
c.message_pos = s;
@ -1299,9 +1282,9 @@ inline size_t Holder::parse(const char* s, size_t n, SemanticValues& sv, Context
return len;
}
inline any Holder::reduce(const SemanticValues& sv, any& dt, const Action& action) const {
if (action) {
return action(sv, dt);
inline any Holder::reduce(const SemanticValues& sv, any& dt) const {
if (outer_->action) {
return outer_->action(sv, dt);
} else if (sv.empty()) {
return any();
} else {
@ -1674,8 +1657,8 @@ private:
auto ignore = (sv.size() == 4);
auto baseId = ignore ? 1 : 0;
const auto& name = sv[baseId].val.get<std::string>();
auto ope = sv[baseId + 2].val.get<std::shared_ptr<Ope>>();
const auto& name = sv[baseId].get<std::string>();
auto ope = sv[baseId + 2].get<std::shared_ptr<Ope>>();
auto& grammar = *data.grammar;
if (grammar.find(name) == grammar.end()) {
@ -1694,11 +1677,11 @@ private:
g["Expression"] = [&](const SemanticValues& sv) {
if (sv.size() == 1) {
return sv[0].val.get<std::shared_ptr<Ope>>();
return sv[0].get<std::shared_ptr<Ope>>();
} else {
std::vector<std::shared_ptr<Ope>> opes;
for (auto i = 0u; i < sv.size(); i++) {
opes.push_back(sv[i].val.get<std::shared_ptr<Ope>>());
opes.push_back(sv[i].get<std::shared_ptr<Ope>>());
}
const std::shared_ptr<Ope> ope = std::make_shared<PrioritizedChoice>(opes);
return ope;
@ -1707,11 +1690,11 @@ private:
g["Sequence"] = [&](const SemanticValues& sv) {
if (sv.size() == 1) {
return sv[0].val.get<std::shared_ptr<Ope>>();
return sv[0].get<std::shared_ptr<Ope>>();
} else {
std::vector<std::shared_ptr<Ope>> opes;
for (const auto& x: sv) {
opes.push_back(x.val.get<std::shared_ptr<Ope>>());
opes.push_back(x.get<std::shared_ptr<Ope>>());
}
const std::shared_ptr<Ope> ope = std::make_shared<Sequence>(opes);
return ope;
@ -1721,11 +1704,11 @@ private:
g["Prefix"] = [&](const SemanticValues& sv) {
std::shared_ptr<Ope> ope;
if (sv.size() == 1) {
ope = sv[0].val.get<std::shared_ptr<Ope>>();
ope = sv[0].get<std::shared_ptr<Ope>>();
} else {
assert(sv.size() == 2);
auto tok = sv[0].val.get<char>();
ope = sv[1].val.get<std::shared_ptr<Ope>>();
auto tok = sv[0].get<char>();
ope = sv[1].get<std::shared_ptr<Ope>>();
if (tok == '&') {
ope = apd(ope);
} else { // '!'
@ -1736,12 +1719,12 @@ private:
};
g["Suffix"] = [&](const SemanticValues& sv) {
auto ope = sv[0].val.get<std::shared_ptr<Ope>>();
auto ope = sv[0].get<std::shared_ptr<Ope>>();
if (sv.size() == 1) {
return ope;
} else {
assert(sv.size() == 2);
auto tok = sv[1].val.get<char>();
auto tok = sv[1].get<char>();
if (tok == '?') {
return opt(ope);
} else if (tok == '*') {
@ -1752,45 +1735,40 @@ private:
}
};
g["Primary"].actions = {
// Default
[&](const SemanticValues& sv) {
return sv[0];
},
// Reference
[&](const SemanticValues& sv, any& dt) {
Data& data = *dt.get<Data*>();
g["Primary"] = [&](const SemanticValues& sv, any& dt) {
Data& data = *dt.get<Data*>();
switch (sv.choice) {
case 0: { // Reference
auto ignore = (sv.size() == 2);
auto baseId = ignore ? 1 : 0;
auto ignore = (sv.size() == 2);
auto baseId = ignore ? 1 : 0;
const auto& ident = sv[baseId].get<std::string>();
const auto& ident = sv[baseId].val.get<std::string>();
if (data.references.find(ident) == data.references.end()) {
data.references[ident] = sv.s; // for error handling
}
if (data.references.find(ident) == data.references.end()) {
data.references[ident] = sv.s; // for error handling
if (ignore) {
return ign(ref(*data.grammar, ident, sv.s));
} else {
return ref(*data.grammar, ident, sv.s);
}
}
if (ignore) {
return ign(ref(*data.grammar, ident, sv.s));
} else {
return ref(*data.grammar, ident, sv.s);
case 1: { // (Expression)
return sv[1].get<std::shared_ptr<Ope>>();
}
case 2: { // Anchor
auto ope = sv[1].get<std::shared_ptr<Ope>>();
return anc(ope);
}
case 3: { // Capture
auto name = std::string(sv[0].s, sv[0].n);
auto ope = sv[1].get<std::shared_ptr<Ope>>();
return cap(ope, data.match_action, ++data.capture_count, name);
}
default: {
return sv[0].get<std::shared_ptr<Ope>>();
}
},
// (Expression)
[&](const SemanticValues& sv) {
return sv[1];
},
// Anchor
[&](const SemanticValues& sv) {
auto ope = sv[1].val.get<std::shared_ptr<Ope>>();
return anc(ope);
},
// Capture
[&](const SemanticValues& sv, any& dt) {
Data& data = *dt.get<Data*>();
auto name = std::string(sv[0].s, sv[0].n);
auto ope = sv[1].val.get<std::shared_ptr<Ope>>();
return cap(ope, data.match_action, ++data.capture_count, name);
}
};
@ -2249,10 +2227,9 @@ private:
for (auto& x: *grammar_) {
const auto& name = x.first;
auto& rule = x.second;
auto& action = rule.actions.front();
if (!action) {
if (!rule.action) {
auto is_token = rule.is_token;
action = [=](const SemanticValues& sv) {
rule.action = [=](const SemanticValues& sv) {
if (is_token) {
return std::make_shared<Ast>(name.c_str(), AstDefaultTag, std::string(sv.s, sv.n));
}

22
test/test.cc
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@ -284,21 +284,21 @@ TEST_CASE("Simple calculator test", "[general]")
peg parser(syntax);
parser["Additive"] = {
// Default action
nullptr,
// Action for the first choice
[](const SemanticValues& sv) { return sv[0].val.get<int>() + sv[1].val.get<int>(); },
// Action for the second choice
[](const SemanticValues& sv) { return sv[0]; }
parser["Additive"] = [](const SemanticValues& sv) {
switch (sv.choice) {
case 0:
return sv[0].get<int>() + sv[1].get<int>();
default:
return sv[0].get<int>();
}
};
parser["Multitive"] = [](const SemanticValues& sv) {
switch (sv.choice) {
case 0: // Action for the first choice
return sv[0].val.get<int>() * sv[1].val.get<int>();
default: // Action for the second choice
return sv[0].val.get<int>();
case 0:
return sv[0].get<int>() * sv[1].get<int>();
default:
return sv[0].get<int>();
}
};

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