C++ library fixes

1 files changed, 139 insertions, 0 deletions

diff --git a/cpp/examples/all_functions.cpp b/cpp/examples/all_functions.cpp
new file mode 100644
index 0000000..326ae39
--- /dev/null
+++ b/cpp/examples/all_functions.cpp
@@ -0,0 +1,139 @@
+// Demonstrates almost all of libpom++'s API
+
+#include <pom.hpp>
+#include <fcntl.h>
+#include <unistd.h>
+#include <iostream>
+
+class FdReader: public pom::Reader {
+public:
+	explicit FdReader(const char *path) {
+		m_fd = open(path, O_RDONLY);
+		if (m_fd == -1) {
+			throw "file doesn't exist";
+		}
+	}
+	~FdReader() { close(m_fd); }
+	size_t read(char *buf, size_t size) {
+		size_t total_read = 0;
+		while (true) {
+			// must call read in a loop to fill buf up as much as possible!
+			// (read isn't guaranteed to read len bytes even if it could)
+			ssize_t ret = ::read(m_fd, buf, size);
+			if (ret < 0) {
+				// read error
+				throw "read error";
+			} else if (ret == 0) {
+				// end-of-file
+				break;
+			} else {
+				total_read += ret;
+				buf += ret;
+				size -= ret;
+			}
+		}
+		return total_read;
+	}
+private:
+	int m_fd;
+};
+
+int main(void) {
+	try {
+		// ordinary usage: load from a path
+		pom::Configuration conf("conf.pom");
+		// get a key
+		std::optional<std::string> indentation_type = conf.get("indentation-type");
+		std::cout << "Indentation type: " << indentation_type.value_or("(none)") << "\n";
+
+		// load configuration with custom settings and a custom reader
+		pom::Settings settings = {};
+		settings.set_error_language("fr"); // erreurs en français
+		FdReader reader("conf.pom");
+		conf = pom::Configuration(
+			"conf.pom", // file name for error messages
+			reader, // object used to read file
+			&settings // settings
+		);
+
+		// nicer way of doing what we did above
+		std::cout << "Indentation type: "
+			<< conf.get_or_default("indentation-type", "(none)")
+			<< "\n";
+
+		// parse value as signed integer
+		std::optional<int64_t> tab_size = conf.get_int("tab-size");
+		std::cout << "tab size: ";
+		if (tab_size.has_value())
+			std::cout << tab_size.value();
+		else
+			std::cout << "(none set)";
+		std::cout << "\n";
+
+		// parse value as unsigned integer, use default of 2
+		std::cout << "padding pixels: "
+			<< conf.get_uint_or_default("padding-pixels", 2)
+			<< "\n";
+
+		// parse value as double
+		std::cout << "font size: "
+			<< conf.get_float_or_default("font-size", 12.5)
+			<< "\n";
+
+		// parse value as boolean
+		std::cout << "show line numbers: "
+			<< (conf.get_bool_or_default("show-line-numbers", true) ? "yes" : "no")
+			<< "\n";
+
+		// extract section out of configuration
+		pom::Configuration file_extensions = conf.section("file-extensions");
+
+		// parse value as list
+		std::vector<std::string> Cpp_extensions = file_extensions.get_list_or_default("Cpp", {});
+		if (!Cpp_extensions.empty()) {
+			for (const std::string &extension: Cpp_extensions)
+				std::cout << "C++ extension: " << extension << "\n";
+		} else {
+			printf("no extensions defined for C++\n");
+		}
+
+		// iterate over keys in section
+		pom::Configuration plugins = conf.section("plug-in");
+		for (std::string &key: plugins.keys()) {
+			pom::Configuration plugin = plugins.section(key);
+			auto path = plugin.get_or_default("path", "(none)");
+			bool enabled = plugin.get_bool_or_default("enabled", true);
+			// get location where key was defined
+			pom::Location location = plugins.location(key).value();
+
+			std::cout << location.file() << ":" << location.line()
+				<< ": plug-in " << key
+				<< " (path = " << path <<
+				", enabled = " << enabled << ")\n";
+		}
+
+		// load config from string
+		pom::Configuration overrides("<built-in overrides>", "tab-size = 12");
+
+		// merge configurations
+		conf.merge(overrides);
+
+		// iterate over items (key-value pairs) in configuration
+		for (const auto &item: conf.items()) {
+			if (item->key().find('b') != std::string_view::npos)
+				std::cout << item->key() << ": " << item->value() << "\n";
+		}
+
+		// iterate over all the keys which haven't been accessed directly
+		for (const std::string &key: conf.unread_keys()) {
+			std::cout << "unrecognized key " << key << "\n";
+		}
+	} catch (pom::Error &error) { // error from libpom++
+		std::cerr << error;
+		return EXIT_FAILURE;
+	} catch (const char *error) { // error from FdReader
+		std::cerr << error << "\n";
+		return EXIT_FAILURE;
+	}
+	return 0;
+}