cemplate

Simple C++ template engine

git clone git://git.dimitrijedobrota.com/cemplate.git

cemplate.cpp (3442B)

1 #include <format> 2 #include <iostream> 3 #include <stack> 4 #include <unordered_set> 5 6 #include "cemplate/cemplate.hpp" 7 8 namespace 9 { 10 11 static std::uint64_t indent_lvl = 0; // NOLINT 12 13 auto indent(std::uint64_t lvl = indent_lvl) 14 { 15 return std::string(lvl * 2, ' '); 16 } 17 18 void warning(const std::string& message, const std::string& addition) // NOLINT 19 { 20 std::cerr << "Warning: " << message; 21 if (!addition.empty()) { 22 std::cerr << " - " + addition; 23 } 24 std::cerr << '\n' << std::flush; 25 } 26 27 } // namespace 28 29 namespace cemplate 30 { 31 32 Pragma::operator std::string() const 33 { 34 return std::format("#pragma {}\n", m_value); 35 } 36 37 Include::operator std::string() const 38 { 39 return std::format("#include <{}>\n", m_header); 40 } 41 42 IncludeL::operator std::string() const 43 { 44 return std::format("#include \"{}\"\n", m_header); 45 } 46 47 Namespace::operator std::string() const 48 { 49 static std::unordered_set<std::string> seen; 50 static std::stack<std::string> stk; 51 52 if (stk.empty() || stk.top() != m_name) { 53 if (seen.contains(m_name)) { 54 warning("nesting namespaces of the same name", m_name); 55 } 56 57 seen.insert(m_name); 58 stk.push(m_name); 59 60 return std::format("namespace {}\n{{\n\n", m_name); 61 } 62 63 seen.erase(m_name); 64 stk.pop(); 65 return std::format("\n}} // namespace {}\n\n", m_name); 66 } 67 68 Return::operator std::string() const 69 { 70 return std::format("{}return {};\n", indent(), m_value); 71 } 72 73 String::operator std::string() const 74 { 75 return std::format(R"("{}")", m_value); 76 } 77 78 Declaration::operator std::string() const 79 { 80 return std::format("{}{} {} = {};\n", indent(), m_type, m_name, m_value); 81 } 82 83 Call::operator std::string() const 84 { 85 return std::format("{}({})", func(), join(args(), ", ")); 86 } 87 88 Statement::operator std::string() const 89 { 90 return std::format("{}{};\n", indent(), m_content); 91 } 92 93 std::string Initlist::format(uint64_t lvl) const 94 { 95 const auto eval = []<typename T>(const T& val, std::uint64_t llvl) 96 { 97 if constexpr (std::is_same_v<T, std::string>) { 98 return std::format("{}{},\n", indent(llvl), val); 99 } else if (std::is_same_v<T, Initlist>) { 100 return std::format( 101 "{}{{\n{}{}}},\n", indent(llvl), val.format(llvl + 1), indent(llvl)); 102 } else { 103 return std::string(); 104 } 105 }; 106 107 std::string res; 108 109 for (const auto& elem : values) { 110 std::visit([&](const auto& val) { res += eval(val, lvl + 1); }, 111 elem.value()); 112 } 113 114 return res; 115 } 116 117 Initlist::operator std::string() const 118 { 119 return std::format("{{\n{}{}}}", format(indent_lvl + 1), indent()); 120 } 121 122 Function::operator std::string() const 123 { 124 static std::string last; 125 126 if (!last.empty()) { 127 if (last != name()) { 128 warning("function is not closed", last); 129 } 130 131 last.clear(); 132 indent_lvl--; 133 return "}\n\n"; 134 } 135 136 if (ret().empty()) { 137 warning("function should have a return type", name()); 138 } 139 140 last = name(); 141 indent_lvl++; 142 return std::format("{} {}({})\n{{\n", ret(), name(), join(params(), ", ")); 143 } 144 145 FunctionD::operator std::string() const 146 { 147 return std::format("{} {}({});\n", ret(), name(), join(params(), ", ")); 148 } 149 150 Template::operator std::string() const 151 { 152 return std::format("{}template <{}>\n", indent(), join(m_params, ", ")); 153 } 154 155 TemplateD::operator std::string() const 156 { 157 return std::format("{}<{}>", m_var, join(m_params, ", ")); 158 } 159 160 Requires::operator std::string() const 161 { 162 return std::format("{}requires {}\n", indent(indent_lvl + 1), m_value); 163 } 164 165 } // namespace cemplate