preprocessor_definition_from_string.cs

//----------------------------------------------------------------------------------------------------------
//----------------------------------------------------------------------------------------------------------
// Overview
//----------------------------------------------------------------------------------------------------------
// GeneratePreProcessorDefinition takes an input string and returns a C++ style pre-processor definition
//----------------------------------------------------------------------------------------------------------
// Usage
//----------------------------------------------------------------------------------------------------------
// string PreProcessorDefinition = GeneratePreProcessorDefinition("Input String");
//----------------------------------------------------------------------------------------------------------
// Examples
//----------------------------------------------------------------------------------------------------------
//                 MyPluginName --> SOME_PREFIX_MY_PLUGIN_NAME
//                MyPluginName1 --> SOME_PREFIX_MY_PLUGIN_NAME_1
//             MyPluginAIModule --> SOME_PREFIX_MY_PLUGIN_AI_MODULE
//                     AIWidget --> SOME_PREFIX_AI_WIDGET
//                    AI1Widget --> SOME_PREFIX_AI_1_WIDGET
//                  AIWidgetFoo --> SOME_PREFIX_AI_WIDGET_FOO
//          MyPluginName1Module --> SOME_PREFIX_MY_PLUGIN_NAME_1_MODULE
//               My Plugin Name --> SOME_PREFIX_MY_PLUGIN_NAME
//              My Plugin1 Name --> SOME_PREFIX_MY_PLUGIN_1_NAME
//              My Plugin 1Name --> SOME_PREFIX_MY_PLUGIN_1_NAME
// lowercase string with spaces --> SOME_PREFIX_LOWERCASE_STRING_WITH_SPACES
//----------------------------------------------------------------------------------------------------------
//----------------------------------------------------------------------------------------------------------

static string GeneratePreProcessorDefinition(string Input)
{
    Func<char, bool> IsSpaceOrSeparator = C => (C == ' ' || C == '_' || C == '-');
    string Output = "SOME_PREFIX_";
    char[] InputChars = Input.ToCharArray();
    for(int i = 0; i < InputChars.Length; ++i)
    {
        char CurrentChar = InputChars[i];
        if(IsSpaceOrSeparator(CurrentChar))
        {
            continue; // Ignore spaces
        }
        else if(i > 0)
        {
            char PreviousChar = InputChars[i - 1];
            if(char.IsUpper(CurrentChar) && i < (InputChars.Length - 1))
            {
                char NextChar = InputChars[i + 1];
                if(char.IsLower(NextChar) || char.IsLower(PreviousChar) || IsSpaceOrSeparator(PreviousChar))
                {
                    // Insert _ if uppercase and previous or next character are lowercase
                    // Insert _ if uppercase and previous character is separator
                    Output += "_";
                }
            }
            else if(char.IsNumber(CurrentChar) && !char.IsNumber(PreviousChar))
            {
                Output += "_"; // Insert _ if this is the first number in a sequence
            }
            else if(PreviousChar == ' ')
            {
                Output += "_"; // Insert _ in place of space
            }
        }
        Output += char.ToUpper(CurrentChar);
    }
    return Output;
}