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Diffstat (limited to 'tomlplusplus/examples/error_printer.cpp')
| -rw-r--r-- | tomlplusplus/examples/error_printer.cpp | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/tomlplusplus/examples/error_printer.cpp b/tomlplusplus/examples/error_printer.cpp new file mode 100644 index 0000000000..c73ea75881 --- /dev/null +++ b/tomlplusplus/examples/error_printer.cpp @@ -0,0 +1,210 @@ +// This file is a part of toml++ and is subject to the the terms of the MIT license. +// Copyright (c) Mark Gillard <mark.gillard@outlook.com.au> +// See https://github.com/marzer/tomlplusplus/blob/master/LICENSE for the full license text. +// SPDX-License-Identifier: MIT + +// This example shows the error messages the library produces by forcing a set of specific parsing +// failures and printing their results. + +#include "examples.hpp" +#include <toml++/toml.hpp> +#include <cctype> // For iscntrl. +#include <iomanip> // For setfill, hex, etc. +#include <optional> + +using namespace std::string_view_literals; + +namespace +{ + inline constexpr auto invalid_parses = std::array{ + "########## comments and whitespace"sv, + "# bar\rkek"sv, + "# bar\bkek"sv, + "# DEL character: '\x7f'"sv, + "# \xf1\x63"sv, + "# val1 = 1\fval2 = 2"sv, + "foo = 1\n\u2000\nbar = 2"sv, + + "########## inline tables"sv, + "val = {,}"sv, + "val = {a='b',}"sv, // allowed when TOML_ENABLE_UNRELEASED_FEATURES == 1 + "val = {a='b',,}"sv, + "val = {a='b',"sv, + "val = {a='b',\n c='d'}"sv, // allowed when TOML_ENABLE_UNRELEASED_FEATURES == 1 + "val = {?='b'}"sv, + "foo = {} \n [foo.bar]"sv, + + "########## tables"sv, + "[]"sv, + "[foo"sv, + "[foo] ?"sv, + "[foo] [bar]"sv, + "[foo]\n[foo]"sv, + "? = 'foo' ?"sv, + "[ [foo] ]"sv, + + "########## arrays"sv, + "val = [,]"sv, + "val = ['a',,]"sv, + "val = ['a',"sv, + + "########## key-value pairs"sv, + "val = 'foo' ?"sv, + "val = "sv, + "val "sv, + "val ?"sv, + "val = ]"sv, + "[foo]\nbar = 'kek'\nbar = 'kek2'"sv, + "[foo]\nbar = 'kek'\nbar = 7"sv, + "[foo.bar]\n[foo]\nbar = 'kek'"sv, + "[foo]\nbar = 'kek'\nbar.kek = 7"sv, + "[foo]\nbar.? = 'kek'"sv, + R"('''val''' = 1)"sv, + R"(a."""val""" = 1)"sv, + "1= 0x6cA#+\xf1"sv, + R"(😂 = 3)"sv, // allowed when TOML_ENABLE_UNRELEASED_FEATURES == 1 + + "########## values"sv, + "val = _"sv, + "val = G"sv, + "PATHOLOGICALLY_NESTED"sv, // generated inline + + "########## strings"sv, + "val = \" \r \""sv, + R"(val = ")"sv, + R"(val = "\g")"sv, + R"(val = "\x20")"sv, // allowed when TOML_ENABLE_UNRELEASED_FEATURES == 1 + R"(val = "\uFFF")"sv, + R"(val = "\uFFFG")"sv, + R"(val = "\UFFFFFFF")"sv, + R"(val = "\UFFFFFGF")"sv, + R"(val = "\uD801")"sv, + R"(val = "\U00110000")"sv, + R"(val = """ """""")"sv, + R"(val = ''' '''''')"sv, + "val = '\n'"sv, + + "########## integers"sv, + R"(val = -0b0)"sv, + R"(val = -0o0)"sv, + R"(val = -0x0)"sv, + R"(val = +0b0)"sv, + R"(val = +0o0)"sv, + R"(val = +0x0)"sv, + R"(val = 1-)"sv, + R"(val = -1+)"sv, + R"(val = -+1)"sv, + R"(val = 1_0_)"sv, + R"(val = 1_0_ )"sv, + R"(val = 01 )"sv, + R"(val = 0b10000000_00000000_00000000_00000000_00000000_00000000_00000000_00000000 )"sv, + R"(val = 0o1000000000000000000000 )"sv, + R"(val = 9223372036854775808 )"sv, + R"(val = 0x8000000000000000 )"sv, + + "########## floats"sv, + R"(val = 100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.0)"sv, + }; + + inline constexpr auto divider = + "################################################################################"sv; + + void print_string(std::string_view str) + { + for (char c : str) + { + if (std::optional<std::string_view> escape_sequence = (c == '\\') ? "\\\\"sv + : (c == '\a') ? "\\a"sv + : (c == '\b') ? "\\b"sv + : (c == '\f') ? "\\f"sv + : (c == '\n') ? "\\n"sv + : (c == '\r') ? "\\r"sv + : (c == '\t') ? "\\t"sv + : (c == '\v') ? "\\v"sv + : std::optional<std::string_view>{}) + { + std::cout << *escape_sequence; + } + else + { + if (c >= 0 && std::iscntrl(c)) + { + // Print a string, just like `toml::impl::control_char_escapes[c]`. + std::ostringstream stream; + stream << "\\u00"sv << std::setfill('0') << std::setw(2) << std::hex << std::uppercase << int{ c }; + std::cout << stream.str(); + } + else + { + std::cout << c; + } + } + } + } + + void print_parse_error(std::string_view doc, const toml::parse_error& err) + { + std::cout << err; + + auto line_num = err.source().begin.line; + + if (auto line = toml::get_line(doc, line_num)) + { + std::cout << "\nLine "sv << line_num << ": "sv; + print_string(*line); + } + std::cout << "\n\n"sv; + } +} + +int main() +{ + const auto parse_and_print_if_error = [](std::string_view str) + { +#if TOML_EXCEPTIONS + try + { + auto result = toml::parse(str); + static_cast<void>(result); + } + catch (const toml::parse_error& err) + { + print_parse_error(str, err); + } +#else + if (auto result = toml::parse(str); !result) + print_parse_error(str, result.error()); +#endif + }; + + for (auto str : invalid_parses) + { + if (str.empty()) + continue; + + // section headings + if (str.substr(0, 10) == "##########"sv) + { + std::cout << divider << '\n'; + std::cout << "# "sv << str.substr(11) << '\n'; + std::cout << divider << "\n\n"sv; + } + + // error messages + else + { + toml::parse_result result; + + if (str == "PATHOLOGICALLY_NESTED"sv) + { + std::string s(1000u, '['); + constexpr auto start = "array = "sv; + memcpy(s.data(), start.data(), start.length()); + parse_and_print_if_error(s); + } + else + parse_and_print_if_error(str); + } + } + return 0; +} |