From 45024d3aaa687e69c1d5793a418691de143ea26b Mon Sep 17 00:00:00 2001 From: yhirose Date: Wed, 11 Feb 2015 23:57:00 -0500 Subject: [PATCH] Added error handling. --- peglib.h | 130 +++++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 93 insertions(+), 37 deletions(-) diff --git a/peglib.h b/peglib.h index 1950045..e11f69e 100644 --- a/peglib.h +++ b/peglib.h @@ -13,10 +13,10 @@ #include #include #include -#include #include #include #include +#include namespace peglib { @@ -352,18 +352,19 @@ private: */ struct Match { - Match(bool _ret, size_t _len, size_t _id) : ret(_ret), len(_len), id(_id) {} - bool ret; - size_t len; - size_t id; + bool ret; + size_t len; + size_t choice; + const char* ptr; + const std::string msg; }; -Match success(size_t len, size_t id = 0) { - return Match(true, len, id); +Match success(size_t len, size_t choice = 0) { + return Match{ true, len, choice, nullptr, std::string() }; } -Match fail() { - return Match(false, 0, -1); +Match fail(const char* ptr, std::string msg = std::string()) { + return Match{ false, 0, (size_t)-1, ptr, msg }; } /* @@ -411,7 +412,7 @@ public: for (const auto& ope : opes_) { auto m = ope->parse(s + i, l - i, v); if (!m.ret) { - return fail(); + return fail(m.ptr, m.msg); } i += m.len; } @@ -462,7 +463,7 @@ public: } id++; } - return fail(); + return fail(s, "no choice candidate was matched"); } size_t size() const { return opes_.size(); } @@ -500,7 +501,7 @@ public: Match parse_core(const char* s, size_t l, Values& v) const { auto m = ope_->parse(s, l, v); if (!m.ret) { - return fail(); + return fail(m.ptr, m.msg); } auto i = m.len; while (l - i > 0) { @@ -541,7 +542,7 @@ public: if (m.ret) { return success(0); } else { - return fail(); + return fail(m.ptr, m.msg); } } @@ -557,7 +558,7 @@ public: Match parse_core(const char* s, size_t l, Values& v) const { auto m = ope_->parse(s, l, v); if (m.ret) { - return fail(); + return fail(s); } else { return success(0); } @@ -576,7 +577,7 @@ public: auto i = 0u; for (; i < lit_.size(); i++) { if (i >= l || s[i] != lit_[i]) { - return fail(); + return fail(s); } } return success(i); @@ -594,7 +595,7 @@ public: Match parse_core(const char* s, size_t l, Values& v) const { // TODO: UTF8 support if (l < 1) { - return fail(); + return fail(s); } auto ch = s[0]; auto i = 0u; @@ -611,7 +612,7 @@ public: i += 1; } } - return fail(); + return fail(s); } private: @@ -626,7 +627,7 @@ public: Match parse_core(const char* s, size_t l, Values& v) const { // TODO: UTF8 support if (l < 1 || s[0] != ch_) { - return fail(); + return fail(s); } return success(1); } @@ -641,7 +642,7 @@ public: Match parse_core(const char* s, size_t l, Values& v) const { // TODO: UTF8 support if (l < 1) { - return fail(); + return fail(s); } return success(1); } @@ -730,6 +731,11 @@ public: return *this; } + Match parse_with_match(const char* s, size_t l) const { + Values v; + return holder_->parse(s, l, v); + } + template bool parse(const char* s, size_t l, T& val) const { Values v; @@ -800,7 +806,7 @@ private: assert(!outer_->actions.empty()); - auto id = m.id + 1; + auto id = m.choice + 1; const auto& ac = (id < outer_->actions.size() && outer_->actions[id]) ? outer_->actions[id] : outer_->actions[0]; @@ -979,7 +985,27 @@ inline Grammar make_peg_grammar() return g; } -inline std::shared_ptr make_grammar(const char* syntax, std::string& start) +inline std::pair find_line(const char* s, const char* ptr) { + auto p = s; + auto col_ptr = p; + auto no = 1; + + while (p < ptr) { + if (*p == '\n') { + no++; + col_ptr = p + 1; + } + p++; + } + + auto col = p - col_ptr + 1; + + return std::make_pair(no, col); +} + +inline std::shared_ptr make_grammar( + const char* syntax, size_t syntax_len, std::string& start, + std::function log = nullptr) { Grammar peg = make_peg_grammar(); @@ -988,7 +1014,7 @@ inline std::shared_ptr make_grammar(const char* syntax, std::string& st start.clear(); // Setup actions - std::set refs; + std::map refs; peg["Definition"] = [&](const std::vector& v) { const auto& name = v[0].get(); @@ -1051,9 +1077,16 @@ inline std::shared_ptr make_grammar(const char* syntax, std::string& st }; peg["Primary"].actions = { - [&](const std::vector& v) { return v[0]; }, - [&](const std::vector& v) { refs.insert(v[0]); return ref(*grammar, v[0]); }, - [&](const std::vector& v) { return v[1]; } + [&](const std::vector& v) { + return v[0]; + }, + [&](const char* s, size_t l, const std::vector& v) { + refs[v[0]] = s; + return ref(*grammar, v[0]); + }, + [&](const std::vector& v) { + return v[1]; + } }; peg["IdentCont"] = [](const char*s, size_t l) { @@ -1081,16 +1114,35 @@ inline std::shared_ptr make_grammar(const char* syntax, std::string& st return any(); }; - if (peg["Grammar"].parse(syntax)) { - for (const auto& name : refs) { - if (grammar->find(name) == grammar->end()) { - return nullptr; + auto m = peg["Grammar"].parse_with_match(syntax, syntax_len); + if (!m.ret) { + if (log) { + auto line = find_line(syntax, m.ptr); + log(line.first, line.second, m.msg.empty() ? "syntax error" : m.msg); + } + return nullptr; + } + + for (const auto& x : refs) { + const auto& name = x.first; + auto ptr = x.second; + if (grammar->find(name) == grammar->end()) { + if (log) { + auto line = find_line(syntax, ptr); + log(line.first, line.second, "'" + name + "' is not defined."); } + return nullptr; } - return grammar; } - return nullptr; + return grammar; +} + +inline std::shared_ptr make_grammar( + const char* syntax, std::string& start, + std::function log = nullptr) +{ + return make_grammar(syntax, strlen(syntax), start, log); } /*----------------------------------------------------------------------------- @@ -1104,8 +1156,8 @@ public: return grammar_ != nullptr; } - bool load_syntax(const char* syntax) { - grammar_ = make_grammar(syntax, start_); + bool load_syntax(const char* s, size_t l, std::function log) { + grammar_ = make_grammar(s, l, start_, log); return grammar_ != nullptr; } @@ -1145,11 +1197,15 @@ private: std::string start_; }; -inline Parser make_parser(const char* syntax) { +inline Parser make_parser(const char* s, size_t l, std::function log = nullptr) { Parser parser; - if (!parser.load_syntax(syntax)) { - throw std::logic_error("PEG syntax error."); - } + parser.load_syntax(s, l, log); + return parser; +} + +inline Parser make_parser(const char* s, std::function log = nullptr) { + Parser parser; + parser.load_syntax(s, strlen(s), log); return parser; }