Added api sketch

src/conversion.cpp

@@ -0,0 +1,89 @@
+#include "yaml-cpp/conversion.h"
+#include <algorithm>
+
+////////////////////////////////////////////////////////////////
+// Specializations for converting a string to specific types
+
+namespace
+{
+	// we're not gonna mess with the mess that is all the isupper/etc. functions
+	bool IsLower(char ch) { return 'a' <= ch && ch <= 'z'; }
+	bool IsUpper(char ch) { return 'A' <= ch && ch <= 'Z'; }
+	char ToLower(char ch) { return IsUpper(ch) ? ch + 'a' - 'A' : ch; }
+
+	std::string tolower(const std::string& str)
+	{
+		std::string s(str);
+		std::transform(s.begin(), s.end(), s.begin(), ToLower);
+		return s;
+	}
+
+	template <typename T>
+	bool IsEntirely(const std::string& str, T func)
+	{
+		for(std::size_t i=0;i<str.size();i++)
+			if(!func(str[i]))
+				return false;
+
+		return true;
+	}
+
+	// IsFlexibleCase
+	// . Returns true if 'str' is:
+	//   . UPPERCASE
+	//   . lowercase
+	//   . Capitalized
+	bool IsFlexibleCase(const std::string& str)
+	{
+		if(str.empty())
+			return true;
+
+		if(IsEntirely(str, IsLower))
+			return true;
+
+		bool firstcaps = IsUpper(str[0]);
+		std::string rest = str.substr(1);
+		return firstcaps && (IsEntirely(rest, IsLower) || IsEntirely(rest, IsUpper));
+	}
+}
+
+namespace YAML
+{
+	bool Convert(const std::string& input, bool& b)
+	{
+		// we can't use iostream bool extraction operators as they don't
+		// recognize all possible values in the table below (taken from
+		// http://yaml.org/type/bool.html)
+		static const struct {
+			std::string truename, falsename;
+		} names[] = {
+			{ "y", "n" },
+			{ "yes", "no" },
+			{ "true", "false" },
+			{ "on", "off" },
+		};
+
+		if(!IsFlexibleCase(input))
+			return false;
+
+		for(unsigned i=0;i<sizeof(names)/sizeof(names[0]);i++) {
+			if(names[i].truename == tolower(input)) {
+				b = true;
+				return true;
+			}
+
+			if(names[i].falsename == tolower(input)) {
+				b = false;
+				return true;
+			}
+		}
+
+		return false;
+	}
+	
+	bool Convert(const std::string& input, _Null& /*output*/)
+	{
+		return input.empty() || input == "~" || input == "null" || input == "Null" || input == "NULL";
+	}
+}
+