cpp-peglib/docs/native.cpp
2021-01-21 20:56:05 -05:00

89 lines
2.4 KiB
C++

#include "../peglib.h"
#include <cstdio>
#include <emscripten/bind.h>
#include <functional>
#include <iomanip>
#include <sstream>
// https://stackoverflow.com/questions/7724448/simple-json-string-escape-for-c/33799784#33799784
std::string escape_json(const std::string &s) {
std::ostringstream o;
for (auto c : s) {
if (c == '"' || c == '\\' || ('\x00' <= c && c <= '\x1f')) {
o << "\\u" << std::hex << std::setw(4) << std::setfill('0') << (int)c;
} else {
o << c;
}
}
return o.str();
}
std::function<void(size_t, size_t, const std::string &)>
makeJSONFormatter(std::string &json, bool &init) {
init = true;
return [&](size_t ln, size_t col, const std::string &msg) mutable {
if (!init) { json += ","; }
json += "{";
json += R"("ln":)" + std::to_string(ln) + ",";
json += R"("col":)" + std::to_string(col) + ",";
json += R"("msg":")" + escape_json(msg) + R"(")";
json += "}";
init = false;
};
}
bool parse_grammar(const std::string &text, peg::parser &peg,
std::string &json) {
bool init;
peg.log = makeJSONFormatter(json, init);
json += "[";
auto ret = peg.load_grammar(text.data(), text.size());
json += "]";
return ret;
}
void parse_code(const std::string &text, peg::parser &peg, std::string &json,
std::shared_ptr<peg::Ast> &ast) {
peg.enable_ast();
bool init;
peg.log = makeJSONFormatter(json, init);
json += "[";
auto ret = peg.parse_n(text.data(), text.size(), ast);
json += "]";
}
std::string lint(const std::string &grammarText, const std::string &codeText, bool opt_mode) {
std::string grammarResult;
std::string codeResult;
std::string astResult;
std::string astResultOptimized;
peg::parser peg;
auto ret = parse_grammar(grammarText, peg, grammarResult);
if (ret && peg) {
std::shared_ptr<peg::Ast> ast;
parse_code(codeText, peg, codeResult, ast);
if (ast) {
astResult = escape_json(peg::ast_to_s(ast));
astResultOptimized = escape_json(
peg::ast_to_s(peg.optimize_ast(ast, opt_mode)));
}
}
std::string json;
json += "{";
json += "\"grammar\":" + grammarResult;
if (!codeResult.empty()) {
json += ",\"code\":" + codeResult;
json += ",\"ast\":\"" + astResult + "\"";
json += ",\"astOptimized\":\"" + astResultOptimized + "\"";
}
json += "}";
return json;
}
EMSCRIPTEN_BINDINGS(native) { emscripten::function("lint", &lint); }