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--- vulcan:defines [2018/05/29 06:25] – created wolfgangriedmann
+++ vulcan:defines [2018/05/29 12:30] (current) – wolfgangriedmann
@@ Line 18: / Line 18: @@
 If you are using the VO compatible class libraries and therefore need the defines from the VO SDK, you should include the library ''SDK_DEFINES.dll'' to your application. You can find this in your VO Xporter folder, probably in the C:\Program Files (x86)\XSharp\VOXPorter folder.
+In a discussion about this Robert wrote the following:
+For me the most important reason to switch back from #define to DEFINE is the way it was implemented and the consequences of this implementation.
+In Vulcan the preprocessor (and the X# preprocessor a well) do a "dumb" Search and Replace for defines and this has unwanted side effects.
+Consider the following code:
+<code>#define DELETE 1
+Function Delete(nRec as LONG) AS LOGIC</code>
+If the preprocessor compatibility command line option (/vo8) is switched on, then this will be preprocessor to:
+<code>FUNCTION 1(nRec as LONG) AS LOGIC</code>
+Please note how the name of the function was replaced by the value of the define.
+This causes many cryptic error messages, making it very difficult for new users to get started.
+Without /vo8 this would only happen if the function name was written in ALL CAPITAL letters.
+The way VO does it (and the way the DEFINE In X# is implemented) this is not handled by te preprocessor. In a later compiler phase the "binder" will lookup names and will find the value and substitute the name in the parse tree with the values.
+The DEFINE itself is stored as a global const value inside the same class where GLOBALs and FUNCTIONs are stored.
+This does not have this side effect.