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Code cleanup.

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This commit is contained in:
yhirose 2015-07-31 21:30:21 -04:00
parent 02957c3668
commit 5e237895f8
2 changed files with 30 additions and 46 deletions
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2
example/Makefile
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@ -9,7 +9,7 @@ CC = g++
CFLAGS = -std=c++1y -g CFLAGS = -std=c++1y -g
endif endif
all: calc calc2 calc3 all: calc calc2 calc3 pl0
calc : calc.cc ../peglib.h calc : calc.cc ../peglib.h
$(CC) -o calc $(CFLAGS) -I.. calc.cc $(CC) -o calc $(CFLAGS) -I.. calc.cc

74
example/pl0.cc
View File

@ -56,6 +56,24 @@ string format_error_message(const string& path, size_t ln, size_t col, const str
return ss.str(); return ss.str();
} }
template <typename T, typename U>
bool has_key(const T& cont, const U& key) {
return cont.find(key) != cont.end();
}
bool read_file(const char* path, vector<char>& buff)
{
ifstream ifs(path, ios::in | ios::binary);
if (ifs.fail()) {
return false;
}
buff.resize(static_cast<unsigned int>(ifs.seekg(0, ios::end).tellg()));
if (!buff.empty()) {
ifs.seekg(0, ios::beg).read(&buff[0], static_cast<streamsize>(buff.size()));
}
return true;
}
struct Environment struct Environment
{ {
Environment(shared_ptr<Environment> outer = nullptr) Environment(shared_ptr<Environment> outer = nullptr)
@ -66,12 +84,7 @@ struct Environment
} }
bool has_variable(const string& ident) const { bool has_variable(const string& ident) const {
if (variables.find(ident) != variables.end()) { return has_key(variables, ident) ? true : (outer_ ? outer_->has_variable(ident) : false);
return true;
} else if (!outer_) {
return false;
}
return outer_->has_variable(ident);
} }
int get_value(const string& ident) const { int get_value(const string& ident) const {
@ -79,11 +92,11 @@ struct Environment
} }
void set_variable(const string& ident, int val) { void set_variable(const string& ident, int val) {
if (variables.find(ident) != variables.end()) { if (has_key(variables, ident)) {
variables[ident] = val; variables[ident] = val;
return; } else {
outer_->set_variable(ident, val);
} }
outer_->set_variable(ident, val);
} }
map<string, int> constants; map<string, int> constants;
@ -92,26 +105,15 @@ struct Environment
private: private:
bool has_constant(const string& ident) const { bool has_constant(const string& ident) const {
if (constants.find(ident) != constants.end()) { return has_key(constants, ident) ? true : (outer_ ? outer_->has_constant(ident) : false);
return true;
} else if (!outer_) {
return false;
}
return outer_->has_constant(ident);
} }
int get_constant(const string& ident) const { int get_constant(const string& ident) const {
if (constants.find(ident) != constants.end()) { return has_key(constants, ident) ? constants.at(ident) : outer_->get_constant(ident);
return constants.at(ident);
}
return outer_->get_constant(ident);
} }
int get_variable(const string& ident) const { int get_variable(const string& ident) const {
if (variables.find(ident) != variables.end()) { return has_key(variables, ident) ? variables.at(ident) : outer_->get_variable(ident);
return variables.at(ident);
}
return outer_->get_variable(ident);
} }
shared_ptr<Environment> outer_; shared_ptr<Environment> outer_;
@ -130,7 +132,7 @@ struct Interpreter
case "while"_: exec_while(ast, env); break; case "while"_: exec_while(ast, env); break;
case "out"_: exec_out(ast, env); break; case "out"_: exec_out(ast, env); break;
case "in"_: exec_in(ast, env); break; case "in"_: exec_in(ast, env); break;
default: throw logic_error("invalid Ast type"); default: exec(ast->nodes[0], env); break;
} }
} }
@ -280,7 +282,7 @@ private:
case "term"_: return eval_term(ast, env); case "term"_: return eval_term(ast, env);
case "ident"_: return eval_ident(ast, env); case "ident"_: return eval_ident(ast, env);
case "number"_: return eval_number(ast, env); case "number"_: return eval_number(ast, env);
default: throw logic_error("invalid Ast type"); default: return eval(ast->nodes[0], env);
} }
} }
@ -315,8 +317,7 @@ private:
case '/': case '/':
if (rval == 0) { if (rval == 0) {
string msg = "divide by 0 error"; string msg = "divide by 0 error";
string s = format_error_message(ast->path, ast->line, ast->column, msg); throw runtime_error(format_error_message(ast->path, ast->line, ast->column, msg));
throw runtime_error(s);
} }
val = val / rval; val = val / rval;
break; break;
@ -329,8 +330,7 @@ private:
const auto& ident = ast->token; const auto& ident = ast->token;
if (!env->has_value(ident)) { if (!env->has_value(ident)) {
string msg = "undefined variable '" + ident + "'..."; string msg = "undefined variable '" + ident + "'...";
string s = format_error_message(ast->path, ast->line, ast->column, msg); throw runtime_error(format_error_message(ast->path, ast->line, ast->column, msg));
throw runtime_error(s);
} }
return env->get_value(ident); return env->get_value(ident);
} }
@ -340,19 +340,6 @@ private:
} }
}; };
bool read_file(const char* path, vector<char>& buff)
{
ifstream ifs(path, ios::in | ios::binary);
if (ifs.fail()) {
return false;
}
buff.resize(static_cast<unsigned int>(ifs.seekg(0, ios::end).tellg()));
if (!buff.empty()) {
ifs.seekg(0, ios::beg).read(&buff[0], static_cast<streamsize>(buff.size()));
}
return true;
}
int main(int argc, const char** argv) int main(int argc, const char** argv)
{ {
if (argc < 2) { if (argc < 2) {
@ -378,9 +365,6 @@ int main(int argc, const char** argv)
// Parse the source and make an AST // Parse the source and make an AST
shared_ptr<Ast> ast; shared_ptr<Ast> ast;
if (parser.parse_n(source.data(), source.size(), ast, path)) { if (parser.parse_n(source.data(), source.size(), ast, path)) {
vector<string> filters = { "program", "statement", "statements", "term", "factor" };
ast = AstOptimizer(false, filters).optimize(ast);
if (argc > 2 && string("--ast") == argv[2]) { if (argc > 2 && string("--ast") == argv[2]) {
ast->print(); ast->print();
} }