From 16493a99bbd5c373a26e74752f204c901d286905 Mon Sep 17 00:00:00 2001 From: Maxime Coste Date: Thu, 25 Nov 2021 08:56:52 +1100 Subject: [PATCH] small regex impl code style tweak --- src/regex_impl.cc | 62 +++++++++++++++++++++-------------------------- 1 file changed, 28 insertions(+), 34 deletions(-) diff --git a/src/regex_impl.cc b/src/regex_impl.cc index 5507273c..2161d113 100644 --- a/src/regex_impl.cc +++ b/src/regex_impl.cc @@ -179,11 +179,10 @@ private: NodeIndex disjunction(uint32_t capture = -1) { - NodeIndex index = new_node(ParsedRegex::Alternation); - get_node(index).value = capture; + NodeIndex index = add_node(ParsedRegex::Alternation, capture); while (true) { - alternative(); + alternative(ParsedRegex::Sequence); if (at_end() or *m_pos != '|') break; ++m_pos; @@ -193,10 +192,10 @@ private: return index; } - NodeIndex alternative(ParsedRegex::Op op = ParsedRegex::Sequence) + NodeIndex alternative(ParsedRegex::Op op) { - NodeIndex index = new_node(op); - while (auto t = term()) + NodeIndex index = add_node(op); + while (term()) {} get_node(index).children_end = m_parsed_regex.nodes.size(); @@ -248,18 +247,18 @@ private: switch (*m_pos) { - case '^': ++m_pos; return new_node(ParsedRegex::LineStart); - case '$': ++m_pos; return new_node(ParsedRegex::LineEnd); + case '^': ++m_pos; return add_node(ParsedRegex::LineStart); + case '$': ++m_pos; return add_node(ParsedRegex::LineEnd); case '\\': if (m_pos+1 == m_regex.end()) return {}; switch (*(m_pos+1)) { - case 'b': m_pos += 2; return new_node(ParsedRegex::WordBoundary); - case 'B': m_pos += 2; return new_node(ParsedRegex::NotWordBoundary); - case 'A': m_pos += 2; return new_node(ParsedRegex::SubjectBegin); - case 'z': m_pos += 2; return new_node(ParsedRegex::SubjectEnd); - case 'K': m_pos += 2; return new_node(ParsedRegex::ResetStart); + case 'b': m_pos += 2; return add_node(ParsedRegex::WordBoundary); + case 'B': m_pos += 2; return add_node(ParsedRegex::NotWordBoundary); + case 'A': m_pos += 2; return add_node(ParsedRegex::SubjectBegin); + case 'z': m_pos += 2; return add_node(ParsedRegex::SubjectEnd); + case 'K': m_pos += 2; return add_node(ParsedRegex::ResetStart); } break; case '(': @@ -306,10 +305,7 @@ private: { case '.': ++m_pos; - if (m_flags & Flags::DotMatchesNewLine) - return new_node(ParsedRegex::AnyChar); - else - return new_node(ParsedRegex::AnyCharExceptNewLine); + return add_node((m_flags & Flags::DotMatchesNewLine) ? ParsedRegex::AnyChar : ParsedRegex::AnyCharExceptNewLine); case '(': { uint32_t capture_group = -1; @@ -347,7 +343,7 @@ private: if (contains("^$.*+?[]{}", cp) or (cp >= 0xF0000 and cp <= 0xFFFFF)) parse_error(format("unexpected '{}'", cp)); ++m_pos; - return new_node(ParsedRegex::Literal, cp); + return add_node(ParsedRegex::Literal, cp); } } @@ -380,12 +376,12 @@ private: if (cp == 'Q') { - auto escaped_sequence = new_node(ParsedRegex::Sequence); + auto escaped_sequence = add_node(ParsedRegex::Sequence); constexpr StringView end_mark{"\\E"}; auto quote_end = std::search(m_pos.base(), m_regex.end(), end_mark.begin(), end_mark.end()); while (m_pos != quote_end) - new_node(ParsedRegex::Literal, *m_pos++); + add_node(ParsedRegex::Literal, *m_pos++); get_node(escaped_sequence).children_end = m_parsed_regex.nodes.size(); if (quote_end != m_regex.end()) @@ -397,33 +393,33 @@ private: // CharacterClassEscape auto class_it = find_if(character_class_escapes, [cp](auto& c) { return c.cp == cp; }); if (class_it != std::end(character_class_escapes)) - return new_node(ParsedRegex::CharType, (Codepoint)class_it->ctype); + return add_node(ParsedRegex::CharType, (Codepoint)class_it->ctype); // CharacterEscape for (auto& control : control_escapes) { if (control.name == cp) - return new_node(ParsedRegex::Literal, control.value); + return add_node(ParsedRegex::Literal, control.value); } if (cp == '0') - return new_node(ParsedRegex::Literal, '\0'); + return add_node(ParsedRegex::Literal, '\0'); else if (cp == 'c') { if (at_end()) parse_error("unterminated control escape"); Codepoint ctrl = *m_pos++; if (('a' <= ctrl and ctrl <= 'z') or ('A' <= ctrl and ctrl <= 'Z')) - return new_node(ParsedRegex::Literal, ctrl % 32); + return add_node(ParsedRegex::Literal, ctrl % 32); parse_error(format("Invalid control escape character '{}'", ctrl)); } else if (cp == 'x') - return new_node(ParsedRegex::Literal, read_hex(2)); + return add_node(ParsedRegex::Literal, read_hex(2)); else if (cp == 'u') - return new_node(ParsedRegex::Literal, read_hex(6)); + return add_node(ParsedRegex::Literal, read_hex(6)); if (contains("^$\\.*+?()[]{}|", cp)) // SyntaxCharacter - return new_node(ParsedRegex::Literal, cp); + return add_node(ParsedRegex::Literal, cp); parse_error(format("unknown atom escape '{}'", cp)); } @@ -542,16 +538,16 @@ private: if (character_class.ctypes == CharacterType::None and not character_class.negative and character_class.ranges.size() == 1 and character_class.ranges.front().min == character_class.ranges.front().max) - return new_node(ParsedRegex::Literal, character_class.ranges.front().min); + return add_node(ParsedRegex::Literal, character_class.ranges.front().min); if (character_class.ctypes != CharacterType::None and not character_class.negative and character_class.ranges.empty()) - return new_node(ParsedRegex::CharType, (Codepoint)character_class.ctypes); + return add_node(ParsedRegex::CharType, (Codepoint)character_class.ctypes); auto class_id = m_parsed_regex.character_classes.size(); m_parsed_regex.character_classes.push_back(std::move(character_class)); - return new_node(ParsedRegex::CharClass, class_id); + return add_node(ParsedRegex::CharClass, class_id); } ParsedRegex::Quantifier quantifier() @@ -604,8 +600,7 @@ private: } } - NodeIndex new_node(ParsedRegex::Op op, Codepoint value = -1, - ParsedRegex::Quantifier quantifier = {ParsedRegex::Quantifier::One}) + NodeIndex add_node(ParsedRegex::Op op, Codepoint value = -1, ParsedRegex::Quantifier quantifier = {ParsedRegex::Quantifier::One}) { constexpr auto max_nodes = std::numeric_limits::max(); const NodeIndex res = m_parsed_regex.nodes.size(); @@ -616,13 +611,12 @@ private: return res; } - bool at_end() const { return m_pos == m_regex.end(); } - ParsedRegex::Node& get_node(NodeIndex index) { return m_parsed_regex.nodes[index]; } + bool at_end() const { return m_pos == m_regex.end(); } [[gnu::noreturn]] void parse_error(StringView error) const